TY - JOUR
A1 - Chakraborty, Gouri
A1 - Das, Prasenjit
A1 - Bhattacharya, Biswajit
A1 - Prinz, Carsten
A1 - Emmerling, Franziska
A1 - Thomas, Arne
T1 - Room-temperature superprotonic conductivity in COOH-functionalized multicomponent covalent organic frameworks
N2 - In solid materials, the development of hydrogen bonding (H-bonding) networks within pores is crucial for efficient proton conductance. In this study, a chemically stable carboxylic acid-functionalized, quinoline-linked 2D microporous covalent organic framework (COF) (Qy-COOH) was synthesized using the Doebner multicomponent reaction (MCR) and compared to a similar framework lacking the –COOH functionality (Qy-H), prepared via an MC Domino reaction. The proton conductivity of the –COOH-functionalized MCR-COF was significantly enhanced, reaching 10−2 S cm−1, attributed to strong H-bonding interactions between water molecules and the dangling –COOH groups within the COF pores. In contrast, the analogous Qy-H framework exhibited a much lower proton conductivity of 10−5 S cm−1, while an imine-based COF showed only 10−6 S cm−1. This work represents the first demonstration of a general strategy to achieve efficient proton conduction in a class of layered 2D –COOH-functionalized COFs, offering superprotonic conductivity without requiring additives at room temperature. The MCR-COF design approach provides a promising pathway for developing highly stable and high-performance proton-conducting materials.
KW - Multicomponebt
KW - COF
KW - Proton Conductivity
KW - Superprotonic
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-653526
DO - https://doi.org/10.1039/D5SC06953J
SN - 2041-6520
SP - 1
EP - 9
PB - Royal Society of Chemistry (RSC)
AN - OPUS4-65352
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Bartczak, Dorota
A1 - Sikora, Aneta
A1 - Goenaga-Infante, Heidi
A1 - Altmann, Korinna
A1 - Drexel, Roland
A1 - Meier, Florian
A1 - Alasonati, Enrica
A1 - Lelong, Marc
A1 - Cado, Florence
A1 - Chivas-Joly, Carine
A1 - Fadda, Marta
A1 - Sacco, Alessio
A1 - Rossi, Andrea Mario
A1 - Pröfrock, Daniel
A1 - Wippermann, Dominik
A1 - Barbero, Francesco
A1 - Fenoglio, Ivana
A1 - Booth, Andy M.
A1 - Sørensen, Lisbet
A1 - Igartua, Amaia
A1 - Wouters, Charlotte
A1 - Mast, Jan
A1 - Barbaresi, Marta
A1 - Rossi, Francesca
A1 - Piergiovanni, Maurizio
A1 - Mattarozzi, Monica
A1 - Careri, Maria
A1 - Caebergs, Thierry
A1 - Piette, Anne-Sophie
A1 - Parot, Jeremie
A1 - Giovannozzi, Andrea Mario
T1 - Multiparameter characterisation of a nano-polypropylene representative test material with fractionation, light scattering, high-resolution microscopy, spectroscopy, and spectrometry methods
N2 - Reference and quality control materials with comparable physicochemical properties to nanoplastic contaminants present in environmental and food nanoplastics are currently lacking. Here we report a nanoplastic polypropylene material prepared using a top-down approach involving mechanical fragmentation of larger plastics. The material was found to be homogeneous and stable in suspension and has been characterised for average particle size, size distribution range, particle number concentration, polypropylene mass fraction and inorganic impurity Content using a wide range of analytical methods, including AF4, cFFF, PTA, (MA)DLS, MALS, SEM, AFM, TEM, STEM, EDS,Raman, ICP-MS and pyGC-MS. The material was found to have a broad size distribution, ranging from 50 nm to over 200 nm, with the average particle size value dependent on the technique used to determine it. Particle number concentration ranged from 1.7–2.4 × 1010 g−1 , according to PTA. Spectroscopy techniques confirmed that the material was polypropylene, with evidence of aging due to an increased level of oxidation. The measured mass fraction was found to depend on the marker used and ranged between 3 and 5 μg g−1 . Inorganic impurities such as Si, Al, Mg, K, Na, S, Fe, Cl and Ca were also identified at ng g−1 levels. Comparability and complementarity across the measurement methods and techniques is also discussed.
KW - Polypropylene
KW - Nanoplastics
KW - Analytics
KW - Reference material
KW - Scattering methods
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-654680
DO - https://doi.org/10.1039/D5EN00917K
SN - 2051-8153
SP - 1
EP - 15
PB - Royal Society of Chemistry (RSC)
AN - OPUS4-65468
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Krause, Christina
A1 - Szymoniak, Paulina
A1 - Lohstroh, W.
A1 - Juranyi, F.
A1 - Zamponi, M.
A1 - Frick, B.
A1 - Al-Sabbagh, Dominik
A1 - Emmerling, Franziska
A1 - Zorn, R.
A1 - Schönhals, Andreas
T1 - Complex molecular dynamics of symmetric model discotic liquid crystals: Comparison of Hexakis(hepta-alkanoyloxy)triphenylene (HOT6) with Hexakis(hexa-alkyloxy)triphenylene (HAT6)
N2 - This study investigates the complex molecular dynamics of discotic liquid crystals (DLCs) by comparing two structurally similar compounds: Hexakis(hepta-alkanoyloxy)triphenylene (HOT6) and Hexakis(hexa-alkyloxy)triphenylene (HAT6) having the same triphenyl core and the same length of the alkyl side chain. The difference of both materials is that the alkyl chain is linked by an oxygen bridge to the triphenylene core for HAT6 and by a ester group for HOT6. Using a combination of broadband dielectric spectroscopy, differential scanning calorimetry, X-ray scattering, and neutron scattering techniques, the research explores the glass transition phenomena and relaxation processes in these materials. HOT6, featuring ester linkages, exhibits distinct dynamic behavior compared to HAT6, including two separate glass transitions indicated by the 1- and 2-relaxation found by dielectric spectroscopy which are assigned to the glassy dynamics of the alkyl side chain in the intercolumnar space and that of the columns, respectively. The study reveals that the ester group in HOT6 leads to increased molecular rigidity and altered packing in the intercolumnar space, as evidenced by X-ray scattering and the vibrational density of states. Neutron scattering confirms localized methyl group rotations and a further relaxation process which relates to the -relaxation revealed by dielectric spectroscopy. The findings contribute to a deeper understanding of glassy dynamics in partially ordered systems and highlight the influence of molecular architecture on relaxation behavior in DLCs.
KW - Discotic Liquid Crystals
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-655171
DO - https://doi.org/10.1039/d5sm01247c
SN - 1744-6848
SP - 1
EP - 17
PB - Royal Society of Chemistry (RSC)
AN - OPUS4-65517
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Shovo, Redoy Gazi
A1 - Thünemann, Andreas
A1 - Katcharava, Zviadi
A1 - Marinvo, Anja
A1 - Hoppe, Richard
A1 - Woltersdorf, Georg
A1 - Du, Mengxue
A1 - Androsch, Rene
A1 - de Souza e Silva, Juliana Martins
A1 - Busse, Karste
A1 - Binder, Wolfgang H.
T1 - Generating Tagged Micro- and Nanoparticles of Poly(ethylene furanoate) and Poly(ethylene terephthalate) as Reference Materials
N2 - Detecting nanoplastic particles in environmental samples and biological tissues remains a significant challenge, especially in view of newly emerging polymers, not yet commercially exploited. Fluorescent labeling provides a tagging strategy to overcome this limitation by reducing the detection limit of individual particles, especially for small-sized particles. We present a method for producing labeled nanoparticles (NP/MP) of poly(ethylene terephthalate) (PET) and poly(ethylene furanoate) (PEF), tagged with Alexa Fluor 633 or Alexa Fluor 647. Our preparations used mechanical grinding or solvent-based approaches (confined impinging jet mixing, ((CIJ, precipitation), generating particles with hydrodynamic diameters of 200–700 nm, displaying long-term stability in water of up to 57 days. Stable suspensions with concentrations of the particles ranging from 10 µg/mL (surfactant-free, by solvent mixing) to 5.88 mg/mL (precipitation, containing surfactant) were generated with zeta-potentials from −5 to −50 mV. Characterization of the nanoparticles by SEC, DSC, and XRD showed no significant changes in molecular weight, thermal behavior, or crystallinity via the solvent-based methods, compared to the pristine polymer, highlighting their suitability for producing standardized nanoparticle dispersions. Fluorescence spectroscopy of the Alexa-dye-labeled particles confirmed the successful incorporation of the Alexa dyes, so improving monitoring of their biological profiles of the PEF-MP/NPs. s-SNOM (near field imaging) could identify individual PEF-particles sized ∼200 nm by direct imaging.
KW - Reference Materials
KW - Nanoplastics
KW - Microplastics
KW - Polymer
KW - Fluorescence
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-655531
DO - https://doi.org/10.1002/marc.202500839
SN - 1521-3927
VL - 47
IS - 4
SP - 1
EP - 11
PB - Wiley VHC-Verlag
CY - Weinheim
AN - OPUS4-65553
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Schwibbert, Karin
A1 - de Eulate Pérez, Elisa García
A1 - Wen, Keqing
A1 - Voss, Heike
A1 - Thiele, Dorothea
A1 - Richter, Anja M.
A1 - Bonse, Jörn
T1 - Escherichia coli repellence via laser-induced periodic surface structures (LIPSS) on titanium: Critical role of biofilm-associated gene expression
N2 - The inconsistency in the observed bacteria-repellent effects of laser-induced surface textures remains a subject of scientific debates. With E. coli TG1 as test strain, we performed biofilm formation assays on ultrashort pulse laser textured titanium. Samples covered with low spatial frequency LIPSS (LSFL) of periods around 750 nm or with high spatial frequency LIPSS (HSFL) featuring smaller periods around 100 nm were processed on polished samples. While LSFL significantly reduce the number of adhering bacteria compared to the polished reference, HSFL do not. Simultaneously, we concentrate our study on bacterial strategies employed for biofilm formation, that is the transcription of the biofilm-associated genes csgB, involved in primary adhesion to a surface, and wza, participating in biofilm maturation. Promoter regions of these genes were cloned into a promotor probe plasmid with the green fluorescent protein GFP+ as reporter and transferred into the test strain. As indicated by the fluorescence intensity of the reporter protein, among the bacteria colonizing LSFL-covered areas, a markedly higher proportion of cells transcribing csgB or wza were detected, compared to the bacterial populations colonizing the polished or HSFL-covered areas. To our knowledge, this is the first study indicating that the antifouling effect of LSFL topographies can be counteracted when bacteria activate biofilm-associated genes.
KW - Laser-induced periodic surface structures (LIPSS)
KW - Titanium
KW - Biofilm
KW - Antifouling
KW - Gene expression
KW - Fluorescence microscopy
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-655572
DO - https://doi.org/10.1016/j.apsusc.2026.166363
SN - 0169-4332
VL - 730
SP - 1
EP - 9
PB - Elsevier B.V.
AN - OPUS4-65557
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Resch-Genger, Ute
T1 - How to get it right with photoluminescence measurements in the UV/VIS/NIR
N2 - Optical measurements of transparent solutions of organic dyes and semiconductor quantum dots and scattering materials such as luminescent nanocomposites and microparticles and phosphors dispersed in liquid and solid matrices play an important role in energy conversion, solid-state lighting, medical diagnostics, and security barcoding. A key performance parameter is the photoluminescence quantum yield QY, i.e., the number of emitted per number of absorbed photons. QY of transparent luminophore solutions can be obtained relative to a fluorescence QY standard of known QY. Such relative QY measurements require a calibrated spectrofluorometer. Here, we address typical sources of uncertainty for luminescence measurements and relative and absolute QY measurements from the instrument and material side and provide recommendations to circumvent or at least minimize them for transparent and scattering samples in the UV/vis/NIR/SWIR.
T2 - Workshop "Photoluminescence Spectroscopy and its application in Materials Research"
CY - Vienna, Austria
DA - 19.02.2026
KW - Quality assurance
KW - Reference material
KW - Fluorescence
KW - Dye
KW - Traceability
KW - Metrology
KW - Calibration
KW - Reference data
KW - Reference product
KW - Digital certificate
KW - NIR
KW - Instrument performance validation
PY - 2026
AN - OPUS4-65575
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Eddah, Mustapha
A1 - Markötter, Henning
A1 - Mieller, Björn
A1 - Widjaja, Martinus Putra
A1 - Beckmann, Jörg
A1 - Bruno, Giovanni
T1 - Multi-Energy High Dynamic Range (HDR) Synchrotron X-ray Computed Tomography applied to LTCC samples
N2 - Synchrotron X-ray computed tomography (SXCT) is regularly used in materials science to correlate structural properties with macroscopic properties and to optimize manufacturing processes. The X-ray beam energy must be adapted to the sample properties, such as size and density. If both strongly and weakly absorbing materials are present, the contrast to the weakly absorbing materials is lost, resulting in image artifacts and a poor signal-to-noise ratio (SNR). One example is a low-temperature co-fired ceramics (LTCC), in which metal connections are embedded in a ceramic matrix and form 3-dimensional conducting structures. This article describes a method of combining SXCT scans acquired at different beam energies, significantly reducing metal artifacts, and improving image quality. We show how to solve the difficult task of merging the scans at low and high beam energy. Our proposed merging approach achieves up to 35% improvement in SNR within ceramic regions adjacent to metallic conductors. In this way, previously inaccessible regions within the ceramic structure close to the metallic conductors are made accessible. The paper further discusses methodological requirements, limitations, and potential extensions of the presented multienergy SXCT merging technique.
T2 - iCT 2026
CY - Linz, Austria
DA - 10.02.2026
KW - Synchrotron x-ray CT
KW - Multi-energy CT
KW - Low-Temperature cofired ceramics
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-655848
SP - 1
EP - 7
CY - e-Journal of Nondestructive Testing
AN - OPUS4-65584
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Kärcher, Victor
A1 - Reiker, Tobias
A1 - da Costa, Pedro F.G.M.
A1 - de Camargo, Andrea S.S.
A1 - Zacharias, Helmut
T1 - Quantum control in size selected semiconductor quantum dot thin films
N2 - We introduce a novel technique for coherent control that employs resonant internally generated fields in CdTe quantum dot (QD) thin films at the L-point. The bulk band gap of CdTe at the L-point amounts to 3.6 eV, with the transition marked by strong Coulomb coupling. Third harmonic generation (λ3 = 343 nm, hν = 3.61 eV) for a fundamental wavelength of λ 1 = 1,030 nm is used to control quantum interference of three-photon resonant paths between the valence and conduction bands. Different thicknesses of the CdTe QDs are used to manipulate the phase relationship between the external fundamental and the internally generated third harmonic, resulting in either suppression or strong enhancement of the resonant third harmonic, while the nonresonant components remain nearly constant. This development could pave the way for new quantum interference–based applications in ultrafast switching of nanophotonic devices.
KW - Nonlinear nanophotonics
KW - Quantum interference
KW - Third harmonic
KW - Coherent control
KW - Thin films
KW - Quantum dots
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-625859
DO - https://doi.org/10.1515/nanoph-2024-0529
VL - 14
IS - 2
SP - 229
EP - 239
PB - Walter de Gruyter GmbH
AN - OPUS4-62585
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Arai, Marylyn Setsuko
A1 - Ravaro, Leandro Piaggi
A1 - Brambilla, Gabriel
A1 - Maia, Lauro June Queiroz
A1 - Reza Dousti, Mohammad
A1 - de Camargo, Andrea Simone Stucchi
T1 - Upconverting Nanoparticles and Cu(I) Complex-Based Platform for Oxygen Sensing, Thermometry, and Emission Color Tuning
N2 - Multifunctional nanoplatforms combine different material properties to meet a wide range of applications, allowing highly customizable systems. In this rapidly advancing research field, we introduce a multifunctional nanomaterial based on the synergy between Tm3+-doped upconverting nanoparticles (UCNPs) and a Cu(I) complex (CuCom). This material is designed for oxygen sensing, optical thermometry, and emission color tuning. In various concentrations, the CuCom complex was electrostatically integrated into a mesoporous silica shell surrounding the core UCNPs (UCNP@mSiO2). The optimized system, UCNP@mSiO2@CuCom-10, was evaluated for different applications. Due to the spectral overlap between the CuCom absorption and the nanoparticles emission, excitation at 980 nm allows most of the UV-blue emission output from the UCNPs to be transferred to the CuCom via luminescent resonance energy transfer (LRET), producing red emission from the molecule. The remaining Tm3+ emission enables optical thermometry, while CuCom’s sensitivity to molecular oxygen supports its application in gas sensing. In upconversion mode, the nanoplatform achieved a Stern−Volmer constant for O2 sensing of 1.64 and demonstrated thermometric relative sensitivities of 0.9% and 1% K−1 at room temperature, with a linear response from 193 to 373 K. Additionally, the emission color of UCNP@mSiO2@CuCom-10 can be tuned from blue to white and yellow, by varying the excitation and temperature, adding further functionality to the system. This multifunctional platform suggests promising applications in biology, medicine, and environmental monitoring.
KW - M
KW - O2 sensing
KW - Upconversion
KW - Luminescence resonance energy transfer (LRET)
KW - Optical thermometry
KW - Mesoporous silica shell
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-625869
SN - 2574-0970
DO - https://doi.org/10.1021/acsanm.4c06351
VL - 8
SP - 854
EP - 862
PB - American Chemical Society (ACS)
AN - OPUS4-62586
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Omar, Hassan
A1 - Ahmadi, Shayan
A1 - Szymoniak, Paulina
A1 - Schönhals, Andreas
T1 - Molecular Mobility of Thin Films of Poly (bisphenol-A carbonate) Capped and with one Free Surface: From Bulk-like Samples down to the Adsorbed Layer
N2 - The molecular mobility of thin films of poly(bisphenol A carbonate) (PBAC) was systematically investigated using broadband dielectric spectroscopy, employing two distinct electrode configurations. First, films were prepared in a capped geometry between aluminum electrodes employing a crossed electrode capacitor (CEC) configuration, down to film thicknesses of 40 nm. The Vogel temperature, derived from the temperature dependence of relaxation rate of the α-relaxation, increases with decreasing film thickness characterized by an onset thickness. The onset thickness depends on the annealing conditions, with less intense annealing yielding a lower onset thickness. Additionally, a broadening of the β-relaxation peak was observed with decreasing thickness, attributed to the interaction of phenyl groups with thermally evaporated aluminum, resulting in a shift of certain relaxation modes to higher temperatures relative to the bulk material. A novel phenomenon, termed the slow Arrhenius process (SAP), was also identified in proximity to the α-relaxation temperature.
For films with thicknesses below 40 nm, nanostructured electrodes (NSE) were utilized, incorporating nanostructured silica spacers to establish a free surface with air. This free surface causes an enhancement in the molecular mobility for the 40 nm sample, preserving the β-relaxation as a distinct peak. The α-relaxation was detectable in the dielectric loss down to 18 nm, shifting to higher temperatures as film thickness is decreased. Notably, the onset thickness for the increase in Vogel temperature was lower in the NSE configuration compared to the CEC setup, attributed to the presence of the polymer-air interface.
KW - Thin polymer films
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-623422
DO - https://doi.org/10.1039/d4sm01238k
SN - 1744-6848
VL - 21
IS - 2
SP - 241
EP - 254
PB - RSC
AN - OPUS4-62342
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - McGonigle, Rebecca
A1 - Glasgow, Jodie
A1 - Houston, Catriona
A1 - Cameron, Iain
A1 - Homann, Christian
A1 - Black, Dominic J.
A1 - Pal, Robert
A1 - MacKenzie, Lewis E.
ED - MacKenzie, Lewis E.
T1 - Autoclave reactor synthesis of upconversion nanoparticles, unreported variables, and safety considerations
N2 - Autoclave reactors are widely used across chemical and biological sciences, including for the synthesis of upconversion nanoparticles (UCNPs) and other nanomaterials. Yet, the details of how autoclave reactors are used in such synthesis are rarely reported in the literature, leaving several key synthesis variables widely unreported and thereby hampering experimental reproducibility. In this perspective, we discuss the safety considerations of autoclave reactors and note that autoclaves should only be used if they are (a) purchased from reputable suppliers/manufacturers and (b) have been certified compliant with relevant safety standards. Ultimately, using unsuitable autoclave equipment can pose a severe physical hazard and may breach legal safety requirements. In addition, we highlight several parameters in autoclave synthesis that should be reported as standard to maximise the reproducibility of autoclave synthesis experiments across materials and chemistry research. We encourage users of autoclave synthesis vessels to: (1) adopt high-safety autoclaves and (2) report the many experimental variables involved to enhance experimental reproducibility.
KW - Reference material
KW - Nano
KW - Particle
KW - Shell
KW - Fluorescence
KW - Lifetime
KW - Decay kinetics
KW - Synthesis
KW - Quality assurance
KW - Method
KW - Energy transfer
KW - Upconversion
KW - Autoclave synthesis
KW - Data comparability
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-625672
DO - https://doi.org/10.1038/s42004-025-01415-3
VL - 8
IS - 1
SP - 1
EP - 7
PB - Springer Science and Business Media LLC
AN - OPUS4-62567
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Xu, Q.
A1 - Szymoniak, Paulina
A1 - Kolmangadi, Mohamed A.
A1 - Yang, Z.
A1 - Wang, S.
A1 - Gao, Y.
A1 - Shang, J.
A1 - Hunger, J.
A1 - Aldiyarov, A.
A1 - Schönhals, Andreas
A1 - Ge, Y.
A1 - Qi, Z.
T1 - Molecular engineering of supramolecular polymer adhesive with confined water and a single crown ether
N2 - Here, we report a water-induced supramolecular polymer built from confined structural water and an intrinsic amphiphilic macrocyclic self-assembly in a nanophase separated structure. The newly designed crown ether macrocycle, featuring strong hydrophilic hydrogen bonding receptor selenoxide and a synergistical hydrophobic selenium-substituted crown core, confines the structural water in a segregated, interdigitated architecture. Although water molecules typically freeze around 0 °C, the confined structural water in this supramolecular polymer remains in a liquid-like state down to 80 °C. Previous studies suggest that multiple crown ether units are needed to generate structural water. However, here, one unit is sufficient to control the formation and disappearance of structural water and consequent supramolecular polymerization. Typically, the DC conductivity of water shows Arrhenius temperature dependency (lnσDC ∝ 1/T). In contrast, this new crown unit maintains water in confined states, which exhibit a Vogel/Fulcher/Tammann behavior (lnσDC ∝ 1/(T-T0)) at temperatures above the glass transition temperature. Moreover, this water-induced supramolecular polymer exhibits remarkable adhesion properties to hydrophilic surfaces and maintains tough adhesion at low temperatures. These findings show how a single small macrocycle can govern the complex structure and functionality of water in supramolecular systems.
KW - Supramolecular polymerization
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-623631
DO - https://doi.org/10.1039/D4SC06771A
SN - 2041-6539
VL - 16
SP - 1
EP - 9
PB - RSC
AN - OPUS4-62363
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Duarte Bernardino, Carolina
A1 - Lee, Mihyun
A1 - Ren, Qun
A1 - Ruehle, Bastian
T1 - Facile Spray-Coating of Antimicrobial Silica Nanoparticles for High-Touch Surface Protection
N2 - The rising threat from infectious pathogens poses an ever-growing challenge. Metal-based nanomaterials have gained a great deal of attention as active components in antimicrobial coatings. Here, we report on the development of readily deployable, sprayable antimicrobial surface coatings for high-touch stainless steel surfaces that are ubiquitous in many healthcare facilities to combat the spread of pathogens. We synthesized mesoporous silica nanoparticles (MSNs) with different surface functional groups, namely, amine (MSN-NH2), carboxy (MSN-COOH), and thiol groups (MSN-SH). These were chosen specifically due to their high affinity to copper and silver ions, which were used as antimicrobial payloads and could be incorporated into the mesoporous structure through favorable host−guest interactions, allowing us to find the most favorable combinations to achieve antimicrobial efficacy against various microbes on dry or semidry high-touch surfaces. The antimicrobial MSNs were firmly immobilized on stainless steel through a simple two-step spray-coating process. First, the stainless steel surfaces are primed with sprayable polyelectrolyte solutions acting as adhesion layers, and then, the loaded nanoparticle dispersions are spray-coated on top. The employed polyelectrolytes were selected and functionalized specifically to adhere well to stainless steel substrates while at the same time being complementary to the MSN surface groups to enhance the adhesion, wettability, homogeneity, and stability of the coatings. The antimicrobial properties of the nanoparticle suspension and the coatings were tested against three commonly found pathogenic bacteria, Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli, as well as a fungal pathogen, Candida albicans. Especially MSN-SH loaded with silver ions showed excellent antimicrobial efficacy against all tested pathogens under application-relevant, (semi)dry conditions. The findings obtained here facilitate our understanding of the correlation between the surface properties, payloads, and antimicrobial activity and show a new pathway toward simple and easily deployable solutions to combat the spread of pathogens with the help of sprayable antimicrobial surface coatings.
KW - Mesoporous silica nanoparticles
KW - Thin films
KW - Antimicrobial coatings
KW - Spray-coating
KW - Infectious diseases
KW - Pathogen transmission
KW - High-touch surfaces
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-626269
DO - https://doi.org/10.1021/acsami.4c18916
SN - 1944-8252
SP - 1
EP - 13
PB - ACS Publications
CY - Washington, DC
AN - OPUS4-62626
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Senbill, Haytham
A1 - Gangan, Amr
A1 - Saeed, Ahmed M.
A1 - Gad, Mohammed E.
A1 - Zeb, Jehan
A1 - Fahmy, Alaa
T1 - Effects of copper/graphene oxide core-shell nanoparticles on Rhipicephalus ticks and their detoxification enzymes
N2 - Nanopesticides have been recently introduced as novel pesticides to overcome the drawbacks of using traditional synthetic pesticides. The present study evaluated the acaricidal activity of Copper/Graphene oxide core-shell nanoparticles against two tick species, Rhipicephalus rutilus and Rhipicephalus turanicus. The Copper/Graphene oxide core-shell nanoparticles were synthetized through the solution plasma (SP) method under different conditions. The nanoparticles synthesized at 180 W and 45 min were highly toxic to Rh. rutilus and Rh. turanicus, with 50% lethal concentration (LC50) values of 248.1 and 195.7 mg ml−1, respectively, followed by those which were synthesized at 120 W/30 mins (LC50 = 581.5 and 526.5 mg ml−1), 120 W/15 mins (LC50 = 606.9 and 686.7 mg ml−1), and 100/45 mins (LC50 = 792.9 and 710.7 mg ml−1), after 24 h of application. The enzyme assays revealed that 180 W/45 min treatment significantly inhibited the activity of acetylcholinesterase (115 ± 0.81 and 123 ± 0.33 U/ mg protein/min) and superoxide dismutase (290 ± 0.18 and 310 ± 0.92 U/ mg protein/min) in Rh. rutilus and Rh. turanicus, respectively, as compared with the negative control. The results also revealed a significantly increased catalase activity (895 ± 0.37 and 870 ± 0.31 U/ mg protein/min) in Rh. rutilus and Rh. turanicus, respectively. The above results indicated that Copper/Graphene oxide core-shell nanoparticles could be a promising alternatives for the management of ticks.
KW - Copper/graphene oxide
KW - Nanopesticides
KW - Rhipicephalus rutilus
KW - Rhipicephalus turanicus
KW - Acetylcholinesterase
KW - Antioxidants
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-629359
DO - https://doi.org/10.1038/s41598-025-86560-4
SN - 2045-2322
VL - 15
SP - 1
EP - 12
PB - Springer Nature
CY - London
AN - OPUS4-62935
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Hörmann, Anja Franziska
T1 - GISAXS and XRR for STOP - M30 update
N2 - With a representative set of samples measured in reflection geometry at the MOUSE we lead through our recent advances in this talk. A thin polystyrene film serves as an example for X-ray reflectivity and we show the effect of polishing on the reflectivity of stainless steel. Polystyrene spheres spin-coated onto different substrates including the polished stainless steel are demonstrated to show the characteristic scattering of spherical particles in GISAXS. We conclude with the first GISAXS data from laser-induced periodic surface structures (LIPSS) recorded at the MOUSE.
T2 - M30 project meeting Surface Transfer of Pathogens (STOP)
CY - Sofia, Bulgaria
DA - 27.02.2025
KW - X-ray reflectivity
KW - Substrate roughness
KW - Grazing incidence
KW - Particle-based coating
PY - 2025
AN - OPUS4-62777
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Ruehle, Bastian
T1 - Natural language processing for automated workflow and knowledge graph generation in self-driving labs
N2 - Natural language processing with the help of large language models such as ChatGPT has become ubiquitous in many software applications and allows users to interact even with complex hardware or software in an intuitive way. The recent concepts of Self-Driving Labs and Material Acceleration Platforms stand to benefit greatly from making them more accessible to a broader scientific community through enhanced user-friendliness or even completely automated ways of generating experimental workflows that can be run on the complex hardware of the platform from user input or previously published procedures. Here, two new datasets with over 1.5 million experimental procedures and their (semi)automatic annotations as action graphs, i.e., structured output, were created and used for training two different transformer-based large language models. These models strike a balance between performance, generality, and fitness for purpose and can be hosted and run on standard consumer-grade hardware. Furthermore, the generation of node graphs from these action graphs as a user-friendly and intuitive way of visualizing and modifying synthesis workflows that can be run on the hardware of a Self-Driving Lab or Material Acceleration Platform is explored. Lastly, it is discussed how knowledge graphs – following an ontology imposed by the underlying node setup and software architecture – can be generated from the node graphs. All resources, including the datasets, the fully trained large language models, the node editor, and scripts for querying and visualizing the knowledge graphs are made publicly available.
KW - Natural Language Processing
KW - Large Language Models
KW - Self-Driving Labs
KW - Materials Acceleration Platforms
KW - Workflows
KW - Nanomaterials
KW - Advanced Materials
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-631947
UR - https://github.com/BAMresearch/MAPz_at_BAM/tree/main/Minerva-Workflow-Generator
DO - https://doi.org/10.1039/d5dd00063g
SN - 2635-098X
SP - 1
EP - 10
PB - Royal Society of Chemistry (RSC)
AN - OPUS4-63194
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Zaki, Mohammad
T1 - Nano- And Advanced Materials Synthesis In A Self-driving Lab (SDL)
N2 - Development of new nano- and advanced materials - or improvement of existing ones - are important drivers in materials research due to the high importance of these material classes for various applications. Traditional laboratory methods for material development often suffer from reproducibility issues, inefficiencies, human errors, and long experimental optimization times. To overcome these challenges and thus accelerate and optimize the process of material synthesis and discovery, we are building a Self-Driving Lab (SDL), in which we integrate robotics for autonomous nanomaterial synthesis, and automated characterization and data analysis for a complete and reliable nanomaterial synthesis workflow. We also leverage artificial intelligence (AI) and machine learning (ML) algorithms to analyze characterization results and plan new experiments to optimize material properties in an ML-guided active learning feedback loop.
Our SDL is very agnostic towards the types of nano- and advanced materials it can synthesize. On the same SDL platform, we successfully synthesized Stober silica, mesoporous silica, copper-oxide, and gold nanoparticles, as well as metal-organic frameworks and more complex structures from multi-step reactions, such as Au@SiO2 and CuO@SiO2 core-shell nanoparticles. All these material syntheses showed excellent reproducibility when run on the SDL platform multiple times.
Automated, in-line characterization measurements of hydrodynamic diameter, zeta potential, and optical properties (absorbance, fluorescence) of the nanomaterials have also been incorporated in the SDL, along with automating data analysis of at-line or off-line characterization techniques such as electron microscopy image analyses [1]. Incorporating these characterization results alongside a machine learning feedback loop that suggests new experimental parameters for obtaining materials with target properties is a key step for developing autonomous, closed-loop optimization processes. In such a process, we typically start by using random sampling to suggest initial experimental parameters, followed by ML-guided active learning algorithms such as Bayesian optimization, artificial neural networks, or downhill simplex optimizers (e.g., Nelder-Mead) that suggest new synthesis parameters to finally arrive at a material with the targeted or enhanced properties. Further improvement and optimization of our SDL has the potential to mitigate challenges faced by traditional approaches and open a way for rapid and reproducible nano- and advanced material synthesis, optimization, and discovery.
T2 - ANAKON Conference 2025
CY - Leipzig, Germany
DA - 10.03.2025
KW - Self-driving laboratories
KW - Materials acceleration platforms
KW - Nanomaterials
KW - Advanced materials
KW - Automation
KW - Robotics
KW - In-line characterization
PY - 2025
AN - OPUS4-62737
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Schoenhals, Andreas
T1 - The bahvior of inonic liquid crystals as investigated by broadband dielectric spectroscopy and complementary methodas
N2 - The behavior of liquid crystals based on phenylbenzoate was investigated using broadband dielectric spectroscopy and advanced calorimetry. The length of the alkyl side chain was systematically varied from 8 to 16 carbon atoms. The experimental results were compared with those obtained from molecular dynamics simulations.
T2 - Sympoium: "Dipoles is soft matter - How they move and organize"
CY - Leuven, Belgium
DA - 06.06.2025
KW - Ionic liquid crystals
PY - 2025
AN - OPUS4-63316
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Szymoniak, Paulina
A1 - Juranyi, F.
A1 - Kruteva, M.
A1 - Zorn, R.
A1 - Schönhals, Andreas
T1 - Low-Frequency Vibrational Density of States of Nanophase- Separated Poly(n‑alkyl methacrylate)s: Confined Phonons and Relationship to Specific Heat
N2 - This study investigates the low-frequency vibrational Density of states of nanophase-separated poly(n-alkyl methacrylate)s (PnMAs) and its relationship to specific heat. This system undergoes a nanophase separation for n > 1 in alkyl side chain-rich domains and a backbone-rich matrix. Using inelastic neutron scattering, the low-frequency vibrational density of states (Boson peak, BP) of PnMAs with varying alkyl side chain lengths (methyl, butyl, hexyl, and octyl) is measured. The results reveal that the BP shifts to higher frequencies with increasing side chain length reaching a maximum. This result indicates a counterbalance of confinement effects and the scattering of the matrix. The behavior of the Boson peak of the PnMAs is compared to other nanophase-separated systems, such as Janus-polynorbornenes and hexakis(n-alkyloxy)triphenylene discotic liquid crystals. The study also explores the connection between the BP and specific heat capacity, showing a linear relationship between the maximum frequency of the BP and the maximum temperature of the specific heat capacity anomaly. Moreover, from the measured vibrational density of states, the specific heat capacity is calculated and compared to experimental results. The comparison reveals qualitative agreement between the calculated and experimental data. These findings provide evidence for the sound wave interpretation of the Boson peak.
KW - Inelastic Neutron Scattering
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-636928
DO - https://doi.org/10.1021/acs.macromol.5c00898
SN - 1520-5835
SP - 1
EP - 12
PB - ACS Publications
AN - OPUS4-63692
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Gawek, Marcel
A1 - Szymoniak, Paulina
A1 - Hülagü, Deniz
A1 - Hertwig, Andreas
A1 - Schönhals, Andreas
T1 - Molecular Mobility of Thin Films and the Adsorbed Layer of Poly(2-vinylpyridine)
N2 - The molecular dynamics of thin films and the adsorbed layer of poly(2-vinylpyridine) (P2VP) were investigated using broadband dielectric spectroscopy (BDS) and spectroscopic ellipsometry. Thin films of P2VP were prepared on silicon substrates and characterized to understand the influence of film thickness on the thermal glass transition temperature (Tg) and molecular mobility. The ellipsometric study revealed a decrease in Tg with decreasing film thickness, attributed to the enhanced mobility at the polymer/air interface. The adsorbed layer, prepared via the solvent leaching approach, exhibited a higher Tg compared to the bulk, indicating reduced molecular mobility due to strong polymer substrate interactions. The dielectric measurements were carried out in two different electrode configurations, crossed electrode capacitors (CEC) and nanostructured electrodes (NSE), where the latter allows for a free surface layer at the polymer/air interface. The relaxation rates of the α-relaxation measured in the CEC geometry collapse into one chart independent from the film thickness. For the thin films measured in the NSE arrangement the relaxation rates slow down with decreasing film thickness which was discussed as related to a stronger interaction of the P2VP segments with the native SiO2 at the surface of the silicon substrate compared to aluminum. It is worth to note that the effect of the enhanced mobility at the polymer/air interface is not observed in the dielectric measurements. BDS measurements in NSE geometry identified an additional relaxation process (α*-relaxation) in thin films, which was more pronounced in the adsorbed layer. This process is hypothesized to be related to molecular fluctuations within the adsorbed layer including the adsorption/desorption dynamics of segments or to a Slow Arrhenius Process (SAP) related to the equilibration dynamics deep in the glassy state.
KW - Thin polymer films
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-637181
DO - https://doi.org/10.1039/d5sm00539f
SN - 1744-6848
SP - 1
EP - 12
PB - Royal Society of Chemistry (RSC)
AN - OPUS4-63718
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Szymoniak, Paulina
A1 - Kolmangadi, Mohamed A.
A1 - Böhning, Martin
A1 - De Souza, N. R.
A1 - Juranyi, F.
A1 - Zorn, R.
A1 - Schönhals, Andreas
T1 - Inelastic and Quasielastic Neutron Scattering on Polynorbornenes with Bulky Carbocyclic Side groups
N2 - This study investigates the molecular mobility and vibrational properties of polynorbornenes with bulky carbocyclic side groups using inelastic and quasielastic neutron scattering techniques. The polymers, synthesized via metathesis and addition polymerization, exhibit varying degrees of microporosity, which ignificantly influences their gas separation performance. By inelastic neutron scattering experiments, it could be shown that all considered polymers have excess contributions to the low frequency vibrational density of states known as the Boson peak. The maximum frequency of the Boson peak correlates to the microporosity of the polymers.
This correlation supports the sound wave interpretation of the Boson peak, suggesting that the microporous structure enhances the compressibility of the material at a microscopic length scale. The molecular mobility, particularly the methyl group rotation, was characterized using elastic scans and quasielastic neutron scattering. The study revealed a temperature dependent relaxation process, with the onset of molecular fluctuations observed around 200 K for the polymer containing methyl groups. For the polymer having no methyl groups only elastic scattering is observed. The methyl group rotation was analyzed in terms of a jump diffusion in a threefold potential with three equivalent energy minima. This leads to an almost correct description of the q dependence of the elastic incoherent scattering function when the number of hydrogen nuclei undergoing the methyl group rotation is considered. It was further evidenced that the fraction of methyl undergoing the methyl group rotation increases with increasing temperature.
KW - Polymers of Intrinsic Microporosity
KW - Neutron scattering
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-630297
DO - https://doi.org/10.1016/j.polymer.2025.128358
SN - 1873-2291
VL - 328
SP - 241
PB - Elsevier Ltd.
AN - OPUS4-63029
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Stühler, Merlin R.
A1 - Makki, Hesam
A1 - Silbernagl, Dorothee
A1 - Dimde, Mathias
A1 - Ludwig, Kai
A1 - Tegner, Bengt E.
A1 - Greve, Christopher
A1 - Rausch, Konstantin
A1 - Herzig, Eva M.
A1 - Köhler, Anna
A1 - Plajer, Alex J.
T1 - Flexibility and Dynamicity Enhances and Controls Supramolecular Self-Assembly of Zinc(II) Metallogels
N2 - Supramolecular self-assembly of stacked architectures is typically achieved through hydrogen bonding or π–π interactions between monomers constructed from stable and inert bonds. In contrast, coordinative interactions of early metals promise distinct self-assembly behaviour due to more flexible bonding geometries and a wider range of stabilities and exchange kinetics. In this report we demonstrate that tailoring the flexible coordination sphere of Zinc(II) complexes via subtle ligand modification promotes not only one but also three-dimensional self-assembly both thermodynamically and kinetically into higher-order fibrous morphologies, the latter being elucidated by electron tomography. As a result, coordination chemistry can be translated into both nanoscopic (fibre stiffness) and macroscopic (thermal gel stability) material properties. Utilizing dynamicity enables gelation via subcomponent self-assembly, constructing the supramolecular polymer network simultaneously with the monomer. Furthermore, coordinative dis- and reassembly via metal-ligand exchange reactions involving the first and second coordination spheres allows for control over gelation and emission of the system. Our report links concepts in supramolecular self-assembly and coordination chemistry by leveraging the unique bonding interactions that cannot be achieved for traditional monomers, promising applications in stimuli-responsive optoelectronics.
KW - Nanomaterial
KW - AFM
KW - Organometallic
KW - Gel
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-634221
DO - https://doi.org/10.1002/adfm.202507793
SN - 1616-301X
SP - 1
EP - 10
PB - Wiley-VCH GmbH
CY - Weinheim
AN - OPUS4-63422
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Hörmann, Anja Franziska
T1 - My surface at a glance: grazing incidence scattering applications
N2 - Three literature examples are presented to demonstrate the wide range of applications of grazing incidence scattering. These examples concern 1) the determination of the density of a porous film, 2) how orientation of conducting polymers is observed in grazing incidence scattering, and 3) how the three-dimensional order of nanoparticles is reflected in the data. To conclude we show recent data from the MOUSE lab demonstrating the new capability to observe intermolecular distances in thin films using the molybdenum X-ray source.
T2 - Surface Transfer of Pathogens (STOP) - M37 meeting
CY - Turin, Italy
DA - 11.09.2025
KW - Grazing incidence
KW - GISAXS
KW - Applications
PY - 2025
AN - OPUS4-64115
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Hussein, S.
A1 - Kühl, A. A.
A1 - Golusda, L.
A1 - Plattner, C.
A1 - Heinze, N.
A1 - Sturm, G.
A1 - Freise, C.
A1 - Traub, Heike
A1 - Schannor, Mathias
A1 - Trajanoski, Z.
A1 - Taupitz, M.
A1 - Siegmund, B.
A1 - Paclik, D.
T1 - Phenotype and function of human monocytes remain mainly unaffected by very small superparamagnetic iron oxide particles
N2 - The field of medical application of organic or inorganic nanoparticles is extensive. Medical nanoparticles offer benefits but pose risks. For safe use in diagnostics and therapy, they should be inert, non-immunogenic, non-aggregating, and avoid long-term accumulation in sensitive tissues like bone marrow or the brain. We have developed in-house very small superparamagnetic iron oxide nanoparticles (VSOP), 7 nm in size, which have been successfully used in preclinical magnetic resonance imaging (MRI) to detect intestinal inflammation, neuroinflammation and atherosclerosis. This study examines nanoparticle effects on human blood cells focusing on monocytes in vitro as a first step toward clinical application. Whole blood and monocytes from healthy donors and patients with inflammatory bowel disease were treated with VSOP in vitro and analyzed for changes in their transcriptome, phenotype and function. RNA sequencing of monocytes identified the transferrin receptor as one of the most significantly downregulated genes after VSOP treatment, likely to limit iron uptake. Whereas whole blood RNA sequencing showed significant changes only in three non-coding genes. CyTOF analysis confirmed that VSOP-treated monocytes remain inactive, with no increased proliferation or altered migration. Metabolically, VSOP uptake enhanced the oxygen consumption rate. This effect was likely due to phagocytosis rather than effects mediated by the VSOP itself, as phagocytosis of latex beads showed comparable results. In summary, the analysis of peripheral blood mononuclear cells and monocytes suggests that VSOP treatment has no major impact on immune cell phenotype or function indicating VSOP as a promising diagnostic tool in MRI for inflammatory bowel disease.
KW - Imaging
KW - Nanoparticle
KW - Monocytes
KW - Contrast agent
KW - Diagnostics
KW - ICP-MS
KW - LA-ICP-MS
KW - VSOP
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-632012
DO - https://doi.org/10.3389/fnano.2025.1584000
SN - 2673-3013
VL - 7
SP - 1
EP - 16
PB - Frontiers Media
CY - Lausanne
AN - OPUS4-63201
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Hülagü, Deniz
A1 - Ermilova, Elena
A1 - Weise, Matthias
A1 - de Préville, Sophie
A1 - Hoffmann, Johannes
A1 - Morán-Meza, José
A1 - Piquemal, Francois
A1 - Hertwig, Andreas
T1 - Characterization of electrical properties in microstructured ITO layers using spectroscopic ellipsometry
N2 - Thin indium tin oxide (ITO) layers are essential in optoelectronics due to their good electrical conductivity, optical transparency in the visible and near infrared regions, substrate adherence and chemical stability. They are widely used in photovoltaic cells, displays, and organic LEDs, and as low emissivity coatings in smart windows and energy-efficient buildings. For nanophotonic devices, understanding the interplay of ITO’s optical and electrical properties is crucial. Electrical resistivity can be tuned by modifying deposition conditions and layer thickness. However, measuring these properties, especially on microstructured surfaces, remains challenging due to the issues like homogeneity and instability during etching.
Spectroscopic ellipsometry (SE), a non-destructive and phase-sensitive optical technique, offers precise measurement of thin film thickness and dielectric properties. In this study, we investigated the layer thickness, optical constants, and sheet resistance of unstructured and microstructured ITO thin layers using SE. Unstructured layers were deposited via DC-magnetron sputtering on silicon (Si) substrates in argon (Ar) atmospheres with varying oxygen (O2) flows.
This multi-technique approach enhances the understanding of ITO layer structuring and provides robust methodologies for correlating optical and electrical properties, advancing metrology for nanotechnology applications and material science. It also opens the pathway to new reference samples and calibration methods for electrical properties involving device-like structured samples.
T2 - ICSE10 - 10th International Conference on Spectroscopic Ellipsometry
CY - Boulder, CO, USA
DA - 08.06.2025
KW - Ellipsometry
KW - Indium tin oxide (ITO)
KW - Scanning microwave microscopy (SMM)
KW - Sheet resistance calibration standards
KW - ITO wet etching
PY - 2025
AN - OPUS4-63631
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Schmitt, Johannes
T1 - Data acquisition system for single particle inductively coupled plasma mass spectrometry (spICP-MS) with nanosecond time resolution
N2 - This study presents our data acquisition system prototype for single particle inductively coupled plasma mass spectrometry (spICP-MS) with nanosecond time resolution (nanoDAQ) and a matching data processing approach for time-resolved data in the nanosecond range. The system continuously samples the secondary electron multiplier (SEM) detector signal with a dwell time of approximately 2 ns and enables detection of gold nanoparticles (AuNP) as small as 7.5 nm with a commercial single quadrupole ICP-MS instrument. [1]
Analysis of acquired transient data is based on the temporal distance between detector events and a derived ion event density. It was shown that the inverse logarithm of the distance between detector events is proportional to particle size. Also, the number of detector events per particle can be used to calibrate and determine the particle number concentration (PNC) of a nanoparticle dispersion.
Particle-by-particle-based analysis of ion event density and other parameters derived from nanosecond time resolution show promising results. High data acquisition frequency of the systems allows recording of a statistically significant number of data points in 60 s or less, which leaves only the sample uptake and rinsing steps as remaining factors for limiting the total measurement time.
T2 - 20th European Winter Conference on Plasma Spectrochemistry
CY - Berlin, Germany
DA - 02.03.2025
KW - ICP-MS
KW - Instrumentation
KW - Nano
KW - Nanoparticle Characterization
PY - 2025
AN - OPUS4-63599
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Speight, Isaiah R.
A1 - Ardila-Fierro, Karen J.
A1 - Hernández, José G.
A1 - Emmerling, Franziska
A1 - Michalchuk, Adam A. L.
A1 - García, Felipe
A1 - Colacino, Evelina
A1 - Mack, James
T1 - Ball milling for mechanochemical reactions
N2 - Mechanochemistry is an emerging field with the potential to pave the way for sustainable chemistry. Although the use of mechanical force to initiate chemical reactions has been recognized for millennia, it has often taken a backseat to thermal and photonic methods. Over the past 30 years, mechanochemistry has seen a resurgence of interest, attracting researchers across the globe. Despite its proven ability to address numerous challenges within the chemical community, mechanochemistry remains on the periphery. This Primer serves as a valuable guide for conducting mechanochemical reactions by ball milling, offering an overview of the processes, methods, tools and terminology necessary to embark on research in this field. It also highlights persistent hurdles such as equipment standardization, understanding the impact of new discoveries and the lack of predictability of reaction outcomes. The Primer’s focus is on how mechanochemical ball milling is used in various chemical transformations, distinguishing it from other forms of mechanochemistry discussed in the literature. With a promising future, this Primer serves as a gateway for those aspiring to contribute to the field’s advancement.
KW - Mechanochemistry
KW - Ball milling
KW - Upscaling
PY - 2025
DO - https://doi.org/10.1038/s43586-025-00401-2
SN - 2662-8449
VL - 5
IS - 1
SP - 1
EP - 18
PB - Springer Science and Business Media LLC
AN - OPUS4-63447
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Rosenbusch, Ivo
A1 - Arai, Marylyn Setsuko
A1 - Rizzo, Fabio
A1 - de Camargo, Andrea S. S.
A1 - Ravoo, Bart Jan
T1 - A host–guest approach to ratiometric pH sensing using upconversion nanoparticles
N2 - A new pH nanosensor based on β-NaYF4:Yb3+/Tm3+ upconversion nanoparticles functionalized with cyclodextrin and a pH-sensitive adamantane-modified nitrobenzoxadiazole dye (NBD-Ad).
KW - Host-guest materials
KW - Upconversion nanoparticles
KW - Ratiometric optical sensors
KW - pH sensing
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-637722
DO - https://doi.org/10.1039/d5na00145e
SN - 2516-0230
VL - 7
IS - 13
SP - 4142
EP - 4151
PB - Royal Society of Chemistry (RSC)
AN - OPUS4-63772
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Go, Eun Sul
A1 - Hong, Eun Ji
A1 - Lee, Ji Yeong
A1 - Stolar, Tomislav
A1 - Peterson, Gregory I.
A1 - Emmerling, Franziska L.
A1 - Kim, Kyoungsoo
A1 - Kim, Jeung Gon
T1 - Insights into Mechanochemical Solid-State Ball-Milling Reaction: Monitoring Transition from Heterogeneous to Homogeneous Conditions
N2 - As mechanochemical synthesis has advanced significantly, there has been intense interest in understanding the underlying mechanisms of these reactions. Given that many mechanochemical processes are conducted in the solid-state without solvation yet sometimes yield faster reactions than those in solution, we sought to address the following question: Are mechanochemical reactions homo- or heterogeneous? To investigate, we employed a model system involving the mixing and copolymerization of l-lactide (LLA) and d-lactide (DLA), monitored through powder X-ray diffraction (PXRD), nuclear magnetic resonance, and differential scanning calorimetry. In situ and ex situ PXRD analyses of the mixture of LLA and DLA showed that vibratory ball milling rapidly transformed the initially heterogeneous lactide mixture into a homogeneous phase within one min due to collisions between the balls and the jar. By varying the milling conditions, we were able to regulate the level of mixing, which subsequently influenced the copolymerization outcomes. In the solid-state ball-milling copolymerization of LLA and DLA in the presence of a catalyst and initiator, multiblock copolymers of poly(l-lactic acid) and poly(d-lactic acid) were formed within one min during the early stage of the reaction, when incomplete mixing of the monomers led to a process governed by phase heterogeneity. In contrast, prolonged polymerization promoted conditions approaching homogeneity, ultimately yielding atactic poly(lactic acid). This transition from heterogeneous to homogeneous reactions is a distinctive feature compared to conventional homogeneous reactions, potentially leading to mechano-exclusive reaction designs.
KW - Mechanochemistry
KW - Ball-milling
KW - Homogeneous reaction
KW - Heterogeneous reaction
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-638008
DO - https://doi.org/10.1021/jacsau.5c00322
SN - 2691-3704
VL - 5
IS - 6
SP - 2720
EP - 2727
PB - American Chemical Society (ACS)
AN - OPUS4-63800
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Deffo, Gullit
A1 - Tamo, Arnaud Kamdem
A1 - Fotsop, Cyrille Ghislain
A1 - Tchoumi, Honorine Hortense Bougna
A1 - Talla, Donald Eric Njiajo
A1 - Wabo, Calice Gildas
A1 - Deussi, Marcel Cédric Ngaha
A1 - Temgoua, Ranil Clément Tonleu
A1 - Doungmo, Giscard
A1 - Njanja, Evangeline
A1 - Tonle, Ignas Kenfack
A1 - Puzari, Panchanan
A1 - Birkemeyer, Claudia
A1 - Ngameni, Emmanuel
T1 - Metal-organic framework-based materials: From synthesis and characterization routes to electrochemical sensing applications
N2 - Metal-organic frameworks (MOFs) are formed by coordination bonds between organic ligands and metal ions or clusters. Their key properties, including high surface area, porosity, and adjustable functionalities, enable diverse applications in gas separation, catalysis, energy storage, luminescence, and more recently, the development of electrochemical sensors. In this review, we provide an overview of various electrochemical methods and discuss different MOF-based electrochemical sensors reported in the literature. We focus on the synthesis of MOFs, their characterization, and the preparation of MOF-based working electrodes for electroanalysis. A brief history of MOFs, along with their nomenclature, classifications, and features, is discussed to provide a chronological understanding of MOFs before delving into their electroanalytical uses. Recent advancements in the use of MOFs as electrode materials for electrochemical sensing have been extensively reviewed and documented, highlighting their increasing relevance in various analytical fields. This review investigates the key properties of MOFs that make them suitable candidates for sensing applications and the ability for post-synthesis modifications to improve their selectivity and sensitivity. It also examines the challenges associated with the synthesis and modification of MOFs, including issues related to scalability, eproducibility, and the stability of the materials under operational conditions. Furthermore, the review discusses potential future directions for the use of MOFs in electrochemical sensing, emphasizing their role as electrode materials to enhance the sensitivity and selectivity of modified sensors for sustainable applications.
KW - Metal-organic frameworks (MOFs)
KW - MOF synthesis and characterization
KW - Electrochemical sensors
KW - Electroanalysis
PY - 2025
DO - https://doi.org/10.1016/j.ccr.2025.216680
SN - 0010-8545
VL - 536
SP - 1
EP - 78
PB - Elsevier B.V.
AN - OPUS4-63742
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Ruehle, Bastian
T1 - Workflow generation, management, and semantic description for Self-Driving Labs
N2 - The software backend that controls the robotic hardware and runs the synthesis workflows is a very important component of any Self-Driving Lab (SDL). On the one hand, it has to deal with orchestrating and managing complex and task-specific hardware through low-level communication protocols and plan and use the available resources as efficiently as possible while executing (parallelized) workflows, on the other hand, it is the interface the users use to communicate with this highly complex platform, and as such, it needs to be as helpful and user-friendly as possible. This includes the AI-aided experimental design in which the system helps the user to decide which experiment to run next, providing automated data analysis from characterization measurements, and offering easy to understand tools and graphical user interfaces for generating the workflows that are executed on the platform. Lastly, the specificity of the workflows and their dependence on the hardware and software of the SDLs necessitates a common description or ontology for making them easily interchangeable and interoperable between different platforms and labs.
In this contribution, we present several key aspects of “Minerva-OS”, the central backend that orchestrates the syntheses workflows of our SDL for Nano- and Advanced Materials Syntheses [1]. One key feature is the resource management or “traffic control” for scheduling and executing parallel reactions in a multi-threaded environment. Another is the interface with data analysis algorithms from in-line, at-line, and off-line measurements. Here, we will give examples of how automatic image segmentation of electron microscopy images with the help of AI [2] can be used for reducing the “data analysis bottleneck” from an off-line measurement. We will also discuss, compare, and show benchmarks of various machine learning (ML) algorithms that are currently implemented in the backend and can be used for ML-guided, closed-loop material optimization in our SDL. Lastly, we will show our recent efforts [3] in making the workflow generation on SDLs more user-friendly by using large language models to generate executable workflows automatically from synthesis procedures given in natural language and user-friendly graphical user interfaces based on node editors that also allow for knowledge graph extraction from the workflows. In this context, we are currently also working on an ontology for representing the process steps of the workflows, which will greatly facilitate the semantic description and interoperability of workflows between different SDL hardware and software platforms.
T2 - Accelerate 2025
CY - Toronto, Canada
DA - 11.08.2025
KW - Nanomaterials
KW - Advanced Materials
KW - Workflows
KW - Machine Learning
KW - SDL
PY - 2025
AN - OPUS4-63936
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Ruehle, Bastian
T1 - Nano- and Advanced Materials Synthesis in a Self-Driving Lab (SDL)
N2 - Nano- and advanced materials have been recognized as a key enabling technology of the 21st century, due to their high potential of driving innovations in new clean energy technologies, sustainable manufacturing by substitution of critical raw materials and replacement of hazardous substances, breakthroughs in energy conversion and storage, improvement of the environmental performance of products and processes, and facilitation of circularity. Consequently, improving tools that enhance the development and optimization cycle of nano- and advanced materials is crucial.
In this contribution, we present our Self-Driving Lab (SDL) for Nano and Advanced Materials [1], that integrates robotics for batched autonomous synthesis – from molecular precursors to fully purified nanomaterials – with automated characterization and data analysis, for a complete and reliable nanomaterial synthesis workflow. By fully automating these three process steps for seven different materials from five representative, completely different classes of nano- and advanced materials (metal, metal oxide, silica, metal organic framework, and core–shell particles) that follow different reaction mechanisms, we demonstrate the great versatility and flexibility of the platform. The system also exhibits high modularity and adaptability in terms of reaction scales and incorporates in-line characterization measurement of hydrodynamic diameter, zeta potential, and optical properties (absorbance, fluorescence) of the nanomaterials. We discuss the excellent reproducibility of the various materials synthesized on the platform in terms of particle size and size distribution, and the adaptability and modularity that allows access to a diverse set of nanomaterial classes. These features underscore the SDL’s potential as a transformative tool for advancing and accelerating the development of nano- and advanced materials, offering solutions for a sustainable and environmentally responsible future.
T2 - Accelerate 2025
CY - Toronto, Canada
DA - 11.08.2025
KW - Nanomaterials
KW - Advanced Materials
KW - Automation
KW - SDL
KW - MAP
PY - 2025
AN - OPUS4-63935
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Huber, Norbert
T1 - Testing and analysis of materials and components ‒ an expedition from lab to field in a digitally transforming world
N2 - In an era where digital transformation is reshaping every facet of our lives, the field of material science and engineering is no exception. This presentation delves into the exciting journey of material and component testing, tracing its path from the confines of the laboratory to the vast expanse of real-world applications, with a particular focus on enhancing safety and reliability. We will explore how modern techniques are pushing the boundaries of conventional material testing, revealing new dimensions of material behavior and performance that are crucial for ensuring safety. The integration of in situ quality control within production processes is revolutionizing manufacturing, ensuring unparalleled precision and reliability, which are essential for maintaining high safety standards.
As we venture into the realm of Structural Health Monitoring (SHM), discover how cutting-edge technologies are being deployed in field applications, from infrastructure to renewable energy sectors, to monitor and ensure the safety and integrity of critical systems. The presentation will also offer a glimpse into the future, where centralized systems for research data management and innovative digital initiatives promise to transform the landscape of material testing and analysis, further bolstering safety measures. Join us to uncover how these advancements are not only enhancing safety and reliability but also paving the way for a digitally interconnected world.
T2 - MaterialsWeek 2025
CY - Frankfurt am Main, Germany
DA - 02.04.2025
KW - Characterization
KW - Materials testing
KW - In situ quality control
KW - Digitalization
PY - 2025
AN - OPUS4-63918
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Lemiasheuski, Anton
A1 - Wehrkamp, F.
A1 - Bajer, Evgenia
A1 - Sonnenburg, Elke
A1 - Göbel, Artur
A1 - Porohovoj, Ilja
A1 - Bettge, Dirk
A1 - Pfennig, Anja
T1 - Practical application of an automated 3D metallography system for the reconstruction and microstructural analysis of porosity in a sintered steel
N2 - In the 3D microstructural analysis of a digital twin of porosity in the sintered steel Astaloy CrA, pore shape, average pore size as well as pore distribution will be analyzed. Porosity plays a major role in powder-metallurgical materials since it greatly impacts the mechanical properties of these materials and therefore represents a key parameter in their characterization. Based on the robot-assisted automated serial sectioning and imaging (RASI) system of the Federal Institute for Materials Research and Testing (BAM, Bundesanstalt für Materialforschung und Prüfung) in Berlin, the technique of metallographic serial sectioning will be used to image the microstructure and reconstruct a digital 3D twin from the stack of images obtained. Compared with an individual 2D microsection, the quantitative microstructural analysis of this 3D twin will enable more accurate conclusions on the shape, size and distribution of pores. This paper will detail the key steps in 3D microstructural analysis, including the metallographic preparation routine, the imaging technique, image alignment as well as the segmentation of pores. After the methodology has been described, the results of the quantitative microstructural analysis will be presented and the validity of quantitative parameters of 3D and 2D images will be compared and discussed. The analysis of more than 10,000 pores revealed a correlation between pore shape and pore size. It was also found that a 2D representation of the material surface is insufficient for a precise quantitative characterization of porosity.
N2 - In der 3D-Gefügeanalyse eines digitalen Zwillings von Poren in einem Sinterstahl des Typs Astaloy CrA werden sowohl die Porenform als auch die durchschnittliche Porengröße und -verteilung analysiert. Die Porosität spielt in pulvermetallurgischen Werkstoffen eine große Rolle, da sie erheblich die mechanischen Eigenschaften beeinflusst und daher bei der Charakterisierung dieser Werkstoffe ein wichtiger Parameter ist. Basierend auf der Verwendung des Robot-Assisted Automated Serial-Sectioning and Imaging (RASI)-Systems der Bundesanstalt für Materialforschung und Prüfung (BAM) in Berlin, wird das metallographische Serienschnittverfahren genutzt, um das Gefüge aufzunehmen und aus dem Bildstapel einen digitalen 3D-Zwilling zu rekonstruieren. Verglichen zu einem 2D-Einzelschliff ermöglicht die quantitative Gefügeanalyse dieses 3D-Zwillings präzisere Aussagen zu Porenform, -größe und -verteilung. Diese Arbeit beschreibt die wesentlichen Schritte, die für eine 3D-Gefügeanalyse nötig sind, darunter die metallografische Präparationsroutine, das Bildgebungs-Verfahren, das Alignment der Bilder sowie die Segmentierung der Poren. Im Anschluss an die methodische Darstellung werden die Ergebnisse der quantitativen Gefügeanalyse präsentiert und ein Vergleich zwischen der Aussagekraft der quantitativen Parameter von 3D- und 2D-Abbildungen diskutiert. Bei der Analyse von über 10.000 Poren konnte eine Korrelation zwischen der Form und der Porengröße aufgezeigt werden. Weiterhin konnte aufgezeigt werden, dass eine 2D-Abbildung der Werkstoffoberfläche nicht ausreichend für eine eindeutige quantitative Beschreibung der Porosität ist.
KW - 3D Metallographie
KW - RASI
KW - Porenstruktur
PY - 2025
DO - https://doi.org/10.1515/pm-2025-0049
SN - 2195-8599
VL - 62
IS - 8
SP - 516
EP - 535
PB - De Gruyter Brill
AN - OPUS4-63930
LA - mul
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Ruehle, Bastian
T1 - Nano- and Advanced Materials Synthesis in a Self-Driving Lab (SDL)
N2 - Nano- and advanced materials have been recognized as a key enabling technology of the 21st century, due to their high potential of driving innovations in new clean energy technologies, sustainable manufacturing by substitution of critical raw materials and replacement of hazardous substances, breakthroughs in energy conversion and storage, improvement of the environmental performance of products and processes, and facilitation of circularity. Consequently, improving tools that enhance the development and optimization cycle of nano- and advanced materials is crucial.
In this contribution, we present our Self-Driving Lab (SDL) for Nano and Advanced Materials [1], that integrates robotics for batched autonomous synthesis – from molecular precursors to fully purified nanomaterials – with automated characterization and data analysis, for a complete and reliable nanomaterial synthesis workflow. By fully automating these three process steps for seven different materials from five representative, completely different classes of nano- and advanced materials (metal, metal oxide, silica, metal organic framework, and core–shell particles) that follow different reaction mechanisms, we demonstrate the great versatility and flexibility of the platform. The system also exhibits high modularity and adaptability in terms of reaction scales and incorporates in-line characterization measurement of hydrodynamic diameter, zeta potential, and optical properties (absorbance, fluorescence) of the nanomaterials. We discuss the excellent reproducibility of the various materials synthesized on the platform in terms of particle size and size distribution, and the adaptability and modularity that allows access to a diverse set of nanomaterial classes. These features underscore the SDL’s potential as a transformative tool for advancing and accelerating the development of nano- and advanced materials, offering solutions for a sustainable and environmentally responsible future.
T2 - Accelerate 2025
CY - Toronto, Canada
DA - 11.08.2025
KW - Nanomaterials
KW - Advanced Materials
KW - Automation
KW - SDL
KW - MAP
PY - 2025
AN - OPUS4-63934
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Walter, Keven
A1 - Hoch, Dominik P.
A1 - Hertweck, Leon
A1 - Balasubramanian, Kannan
A1 - Geisler, Jonas
A1 - Röllig, Mathias
A1 - Neubert, Tilmann J.
A1 - Börner, Hans G.
T1 - Unlocking the Essence of Lignin: High‐Performance Adhesives That Bond via Thiol‐Catechol Connectivities and Debond on Electrochemical Command
N2 - AbstractThe next generation of adhesives requires effective debonding capabilities that can be triggered on demand to enable advanced circular repair and recycling strategies. A new class of lignin‐inspired, two‐component (2K) structural adhesives offers bonding strengths of up to 20 MPa and clean, on‐command electrochemical debonding within 5–30 min. The debonding is induced by a distinct electrochemical oxidation of thiol‐catechol connectivities (TCCs) within the entire adhesive network, enforcing rapid and clean adhesive failure on the cathodic substrate side. The TCC‐functionalities are formed during curing by a thiol‐quinone Michael‐type polyaddition, reacting polyester‐based trithiols with tris‐quinones as lignin‐inspired minimal building blocks. The structural adhesive can be fine‐tuned by adjusting the formulation. The addition of carbon black and ionic liquids facilitates the desired electrochemical transformation of TCC‐catechols to TCC‐quinones. Applying only 9 V for 5–30 min, leads to clean debonding with 72–86% loss of shear strength. A comprehensive study of curing, bonding, and debonding behavior by rheological, spectroscopic, and electrochemical investigations reveals the debonding mechanism by correlating catechol oxidation to adhesive performance. The electrochemical debonding capability of TCC‐structural adhesives is demonstrated in a functional prototype, where on‐command detachment of a cover glass from a display device is achieved within 6.5 min.
KW - Lignin-inspired
KW - Electrochemical-Debonding
KW - Thiol-Catechol-Connectivity (TCC)
KW - Michael-Type Polyaddition
KW - On-Demand Adhesive Failure
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-639674
DO - https://doi.org/10.1002/adma.202510463
SN - 0935-9648
SP - 1
EP - 10
PB - Wiley VHC-Verlag
CY - 69451 Weinheim
AN - OPUS4-63967
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Yildirim, Arda
A1 - Haug, T. C. V.
A1 - Fröba, M.
A1 - Huber, P.
A1 - Schönhals, Andreas
T1 - Molecular fluctuations in mixed-metal MOF-74: influence of the metal composition
N2 - A selected series of metal–organic frameworks M-MOF-74 (M = Mg, Co, Ni) and mixed metal MM-MOF-74 (Mg/Co or Mg/Ni) with different compositions of metal atoms have been prepared and further investigated by broadband dielectric spectroscopy (BDS) in a wide temperature range. The dielectric spectra show at least two relaxation processes. Process-A is observed only for the Ni-containing MOFs and is attributed to localized fluctuations of the metal oxide corners. Relaxation processes-B and -C are observed for all prepared MOFs, except that process-B is not observed for Ni-MOF-74. Large-angle fluctuations such as free rotations of the linkers can be excluded due to the structure of MOF-74, but small-angle fluctuations such as torsions are possible. According to numerical simulations carried out for MOF-74, process-B can be attributed to inward and outward fluctuations of the linkers relative to the pore center.
Process-C is related to small-angle rotational fluctuations of the linker together with co-rotations of the metal nodes. The latter interpretation is supported by the dependence of the activation energy of the relaxation rate of process-C on the metal composition of the MOFs, which is discussed in terms of the bond lengths between the metal atoms and the linker which decrease in the sequence Mg, Co and Ni.
KW - Metal Organic Frameworks
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-639378
DO - https://doi.org/10.1039/d5ra05357a
SN - 2046-2069
VL - 15
IS - 35
SP - 29109
EP - 29118
PB - Royal Society of Chemistry (RSC)
AN - OPUS4-63937
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Kolmangadi, Mohamed A.
A1 - Raab, A. R.
A1 - Szymoniak, Paulina
A1 - Li, Z.
A1 - Huber, P.
A1 - Laschat, S.
A1 - Schönhals, Andreas
T1 - Molecular mobility and electrical conductivity of amino acid-based (DOPA) ionic liquid crystals in the bulk state and nanoconfinement
N2 - This study explores the molecular mobility, phase behavior, and electrical conductivity of dihydroxyphenylalanine-based ionic liquid crystals (DOPAn, with alkyl side chains n = 12, 14, 16) featuring cyclic guanidiniumchloride headgroups, in both bulk and nanoconfined states. Using broadband dielectric spectroscopy, differential scanning calorimetry, and fast scanning calorimetry, the research uncovers a complex interplay between molecular structure, self-assembly, and molecular mobility. In bulk, DOPAn shows a phase sequence from plastic crystalline to hexagonal columnar and isotropic phases, driven by superdisc formation and columnar organization. Multiple relaxation processes are identified: localized side-chain dynamics (γ-relaxation), ionic headgroup or core motions (α1-relaxation), and cooperative alkyl domain fluctuations (α2-relaxation). Conductivity decreases with increasing side chain length. Under nanoconfinement in anodic aluminum oxide membranes, phase behavior changes: the Colh–Iso transition is suppressed, and a new α3-relaxation appears, linked to dynamics in an adsorbed interfacial layer. DC conductivity drops by up to four orders of magnitude due to confinement effects, altered molecular orientation, and phase transitions—especially the emergence of a nematic-like state in DOPA16. These findings highlight the importance of molecular design, pore geometry, and surface chemistry in tuning ionic liquid crystal properties for advanced applications in nanofluidics, ion transport, and responsive materials.
KW - Ionic Liquid Crystals
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-639657
DO - https://doi.org/10.1039/d5cp02406d
SN - 1463-9084
SP - 1
EP - 17
PB - Royal Society of Chemistry (RSC)
AN - OPUS4-63965
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Szymoniak, Paulina
T1 - Bio-Based Vitrimers: Cracking the Code of Recyclability, Exchange Reactions and Flame Retardancy
N2 - Vitrimers are a promising class of sustainable materials that offer an alternative to traditional epoxy thermosets in line with circular economy principles. Built on covalent adaptive networks (CANs), they can rearrange their chemical bonds in response to external stimuli, giving them properties like recyclability, shape-memory, and self-healing. These materials combine the strength of thermosets with the reprocessability of thermoplastics, making them attractive for next-generation applications.
This study focuses on a bio-based vitrimer made from glycerol triglycidyl ether (GTE) and a vanillin-derived imine hardener (VA), which reacts through catalyst-free imine metathesis. To better understand the recyclability mechanisms of such systems, especially the dynamic bond exchange, we apply a comprehensive suite of techniques including dielectric spectroscopy, neutron scattering, mechanical analysis, and calorimetry. By linking molecular dynamics with macroscopic performance, the work aims to support the development of vitrimers as practical, recyclable materials.
T2 - EPF2025 - European Polymer Congress
CY - Groningen, The Netherlands
DA - 22.06.2025
KW - Polymer recycling
PY - 2025
AN - OPUS4-63859
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Hülagü, Deniz
A1 - Ermilova, Elena
A1 - Weise, Matthias
A1 - de Préville, Sophie
A1 - Hoffmann, Johannes
A1 - Morán‐Meza, José
A1 - Piquemal, François
A1 - Hertwig, Andreas
T1 - Multimethod Electrical Characterization of Thin Indium Tin Oxide Films: Structuring and Calibration Sample Development for Scanning Probe Microscopy
N2 - Indium tin oxide (ITO), a transparent conductive oxide, is widely used in optoelectronic applications due to its electrical conductivity, optical transparency, and chemical stability. This study employs spectroscopic ellipsometry (SE) to analyze ITO layers, enabling nondestructive determination of film thickness, dielectric functions, and bulk conductivity. Electrical properties derived from SE are compared with those obtained using the four‐point probe method (4PM) to improve metrological tools for nanotechnology applications and optimize deposition process monitoring for better control of film properties. This work also investigates the chemical stability of ITO layers under etching conditions and explores the development of new sheet resistance standards for scanning microwave microscopy (SMM). The results show that ITO resistivity, calculated from fitted SE data, increases with oxygen flow rate up to 5 cm3(STP) min−1. Good agreement is observed between sheet resistance values obtained by SE and 4PM up to 3 cm3(STP) min−1. Additionally, the sheet resistance values of a distinct set of microstructured ITO samples with different ITO layer thicknesses are determined by SMM, which are highly consistent with those obtained by the 4PM.
KW - Ellipsometry
KW - Indium tin oxide (ITO)
KW - Scanning microwave microscopy (SMM)
KW - Sheet resistance calibration standards
KW - ITO wet etching
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-626242
DO - https://doi.org/10.1002/pssa.202400871
SN - 1862-6300
VL - 222
IS - 14
SP - 1
EP - 18
PB - Wiley
CY - Hoboken, New Jersey, USA
AN - OPUS4-62624
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Szymoniak, Paulina
T1 - Nanoscale Confinement Effects in Thin Films of Rigid-Backbone Polymers
N2 - Thin polymer films play a crucial role in modern technologies, with applications spanning flexible electronics, membranes, coatings, and nanodevices. Their reduced dimensions result in unique physical behavior, often deviating significantly from bulk properties due to confinement and interfacial effects. In this study, we investigate how nanoscale confinement and polymer–substrate interactions influence the structural and dynamic properties of supported thin films of two rigid-backbone polymers: poly(bisphenol A carbonate) (PBAC) and polysulfone (PSU). Emphasis was placed on the development of adsorbed interfacial layers, molecular mobility, and the glass transition behavior as functions of film thickness and thermal history. Using a multimodal experimental approach—including Atomic Force Microscopy (AFM), Broadband Dielectric Spectroscopy (BDS), Differential and Fast Scanning Calorimetry (DSC, FSC), and Ellipsometry—we characterized adsorption kinetics, desorption processes, and segmental dynamics across a wide range of thicknesses and annealing conditions. Special attention was given to the formation and growth regimes of the adsorbed polymer layers, including a newly observed pre-growth stage, and their effect on thermal and dielectric relaxation behavior. To probe dynamics in ultrathin films, two dielectric electrode configurations—crossed electrode capacitors and nanostructured electrodes—were employed, enabling measurements down to 10 nm and isolated adsorbed layer. This comprehensive analysis provides insight into how one-dimensional confinement and interfacial interactions modulate macromolecular behavior, which is critical for the design of functional nanostructured polymeric systems in advanced applications.
T2 - 10th International Discussion Meeting on Relaxations in Complex Systems (10thIDMRCS)
CY - Barcelona, Spanien
DA - 20.06.2025
KW - Thin films
PY - 2025
AN - OPUS4-63858
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Kamoun, E.
A1 - Afifi, K.
A1 - Szymoniak, Paulina
A1 - Schönhals, Andreas
A1 - Fahmy, Alaa
T1 - Structure-property relationship of cross-linked chitosan-ethyl cellulose membranes
N2 - Intensive research is focused on creating cost-effective, high-performance polyelectrolyte membranes (PEMs) for electrochemical devices designed to generate and/or store electrical energy. On the other hand, biopolymer materials have been utilized in a wide range of applications across medical and engineering fields, as well as in the textile and energy sectors. Therefore, in this study, chemically cross-linked chito-san/ethyl cellulose-citric acid (CS-EC-CA) membranes were prepared by a casting technique. The structure-property relationship of CS-EC/CA has been discussed based on the molar ratio of CS. The structural properties of the resultant membrane were characterized using Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy, thermal stability was assessed using thermogravimetric analysis.
Moreover, the ion exchange capacity (IEC) and water uptake of the membrane were studied. FTIR analysis revealed a significant broadening of absorption peaks in the range of 3200–3500 cm-1 , corresponding to -OH groups, presence of CA. A new peak at 1725 cm-1 confirmed the formation of chemical linkages between CA and CS-EC. The results of the thermal analysis revealed that a thermally stable membrane was obtained when it was chemically cross-linked compared to non-cross-linked membranes. The IEC values of the modified membranes were enhanced significantly, increasing from 0.08 mmol/g for pure CS to 0.5 mmol/g for CS (50%) and 0.8 mmol/g for CS (50%) cross-linked withCA. Furthermore, the cross-linked membranes demonstrated the lowest water and ethanol uptake values, emphasizing their suitability for fuel cell applications.
KW - Polyelectrolyte membranes
PY - 2025
DO - https://doi.org/10.1063/5.0279022
SN - 1089-7666
VL - 37
IS - 8
SP - 1
EP - 11
PB - AIP Publishing
AN - OPUS4-63890
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Gugin, Nikita
T1 - Advancing Industrial Mechanochemistry: Real-Time Insights for Sustainable, Solvent-Free Manufacturing
N2 - Mechanochemistry is an environmentally friendly synthetic approach that enables the sustainable production of a wide range of chemicals while reducing or eliminating the need for solvents. Reactive extrusion aims to move mechanochemistry from its conventional gram-scale batch reactions, typically performed in laboratory ball mills, to a continuous, large-scale process. Meeting this challenge requires in situ monitoring techniques to gain insights into reactive extrusion and its underlying processes. While the effectiveness of in situ Raman spectroscopy in providing molecular-level information has been demonstrated, our study uses energy-dispersive X-ray diffraction to monitor reactive extrusion in real time at the crystalline level. Our results provide previously unavailable control over thereactiveextrusion process, promoting its perception as an industrially feasible green alternative to traditional solventbased syntheses.
T2 - #RSCPoster 2025
CY - Online meeting
DA - 04.03.2025
KW - Mechanochemistry
PY - 2025
AN - OPUS4-63803
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Gugin, Nikita
T1 - Advancing Industrial Mechanochemistry: Real-Time Insights for Sustainable, Solvent-Free Manufacturing
N2 - Reactive extrusion has emerged as a continuous approach for conducting mechanochemical reactions on a large scale. However, the use of this method under industrial conditions is hindered by limited understanding. In this study, we unveil the black box of reactive extrusion by employing energy-dispersive X-ray diffraction (EDXRD) to collect time- and spatially resolved in situ data. Our findings demonstrate the EDXRD method’s applicability to a range of chemical transformations and conditions associated with reactive extrusion.
T2 - Chemie-Kolloquium & IfC Science Day
CY - Berlin, Germany
DA - 22.01.2025
KW - Mechanochemistry
PY - 2025
AN - OPUS4-63801
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Nicolai, Marcel
T1 - Investigating Lamb wave mode repulsion with a spring-based model
N2 - Lamb waves are widely utilized in material characterization, non-destructive testing (NDT), and structural health monitoring (SHM). A unique feature of Lamb waves is mode repulsion, where dispersion curves approach each other but do not cross. This phenomenon is observed in both single and multilayer plates and is influenced by wave coupling. While mode repulsion in single plates has been linked to symmetry-breaking effects, its underlying mechanism in multilayer systems remains unclear. This study investigates mode repulsion in a coupled aluminum-polycarbonate plate system using a spring-based interface model. Dispersion curves are computed via the Scaled Boundary Finite Element Method, and time-domain simulations are used to analyze the interface dynamics. Results indicate that repulsion depends on interface stiffness, distinguishing between opening and closing repulsion regions. The study further reveals that mode repulsion corresponds to distinct oscillatory behaviors in the interface, where certain wave modes induce increased coupling spring elongation, leading to localized strain. A coupled harmonic oscillator model effectively explains opening repulsion regions but does not fully capture closing regions. Findings suggest that mode repulsion could be leveraged for non-destructive evaluation of adhesive interfaces, offering insights into bond strength characterization. This research contributes to a deeper understanding of wave interactions in multilayer structures and provides a theoretical foundation for advancing NDT and SHM techniques.
T2 - ICU2025 - International Congress on Ultrasonics 2025
CY - Paderborn, Germany
DA - 21.09.2025
KW - Lamb waves
KW - Mode repulsion
KW - Coupled plates
KW - Dispersion curves
KW - Elastic Interfaces
PY - 2025
AN - OPUS4-64225
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Azimzada, Agil
A1 - Meermann, Björn
T1 - AF4/ICP-ToF-MS for the investigation of species-specific adsorption of organometallic contaminants on natural colloidal particles
N2 - Organotin (OT) compounds, while crucial in many industrial applications, pose substantial risks to the environment and human health. The toxicity and environmental behaviour of OTs depend on their chemical form, i.e., the type and number of organic substituents. Each species thus exhibits distinct toxicity profiles and varying binding affinities to environmental colloids, which influence their mobility, bioavailability, and environmental impacts. To date, however, most studies addressed speciation and colloidal characterization separately, leaving the combined determinations of organometallics along with their carrier colloids largely elusive. Here, we develop and validate an on-line measurement system to quantify the adsorption dynamics of 10 OT species on natural colloidal particles (<500 nm). The approach integrates a versatile fractionation technique (AF4), with a state-of-the-art multi-element analyzer (ICP-ToF-MS), achieving Sn detection limits as low as 6.0 ng/L. The method separates colloid-free OT species from those bound to colloids and enables the determination of OT interactions with distinct colloidal fractions. Validated in both fractionation and detection, the method provides reliable data that could elucidate the species-specific and temporal aspects of species-colloids adsorption processes. The results feature comparative studies of 10 OT species, offering critical insights into OT mobility and distribution in environmental systems.
KW - Fractionation
KW - Speciation
KW - Adsorption
KW - Colloids
KW - Organotin
KW - AF4
KW - Nanoparticle characterization
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-625244
DO - https://doi.org/10.1016/j.jhazmat.2025.137320
SN - 1873-3336
VL - 488
SP - 1
EP - 11
PB - Elsevier B.V.
AN - OPUS4-62524
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Wimmer, L
A1 - Hoang, M V N
A1 - Schwarzinger, J
A1 - Jovanovic, V
A1 - Adelkovic, B
A1 - Velickovic, T C
A1 - Meisel, T C
A1 - Waniek, T
A1 - Weimann, Christiane
A1 - Altmann, Korinna
A1 - Dailey, L A
T1 - A quality-by-design inspired approach to develop PET and PP nanoplastic test materials for use in in vitro and in vivo biological assays
N2 - Micro- and nanoplastics have become environmental pollutants of concern, receiving increased attention from consumers, scientists, and policymakers. The lack of knowledge about possible impacts on wildlife and human health requires further research, for which well-characterized testmaterials are needed. A quality-bydesign (QbD) driven approachwas used to produce sterile, endotoxinmonitored nanoplastics of polyethylene terephthalate (PET) and polypropylene (PP) with a size fraction of >90% below 1 μm and high yield of >90%. Glycerol was used as a versatile and biocompatible liquid storage medium which requires no further exogenous dispersing agent andmaintained colloidal stability, sterility (0 CFU mL−1), and low endotoxin levels (<0.1 EU mL−1) for more than one year of storage at room temperature. Further, the glycerol vehicle showed no biological effect on the tested human bronchial cell line Calu-3 up to 0.8% (w/v). Given the concentration of 40 mg g−1 nanoplastics in the glycerol stock, this corresponds to a nanoplastic concentration of 320 μg mL−1. The surfactant-free nanoplastics are dispersible in bio-relevant media from the glycerol stock without changing size characteristics and are suitable for in vitro and in vivo research.
KW - Microplastics
KW - Reference materials
KW - Nanoplastics
KW - Polymer 3R
KW - Glycerol
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-629934
DO - https://doi.org/10.1039/D4EN01186D
SN - 2051-8161
VL - 12
IS - 5
SP - 2667
EP - 2686
PB - Royal Society of Chemistry
CY - Cambridge
AN - OPUS4-62993
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Engelhard, Carsten
T1 - On ICP-MS with Nanosecond Time Resolution: From Nanoparticles to Microplastics
N2 - In this presentation, recent developments in inductively coupled plasma mass spectrometry (ICP-MS) instrumentation for particle characterization in complex mixtures will be reviewed. The current state-of-the-art in single-particle (sp) ICP-MS instrumentation for the detection and characterization of nanoparticles (NP) and microplastics (MPs) as well as remaining challenges will be discussed.
While millisecond dwell times were used in the advent of spICP-MS, the use of microsecond dwell times helped to improve nanoparticle data quality and particle size detection limits. We could show that a custom-built high-speed data acquisition unit with microsecond time resolution (μsDAQ) can be used to successfully address issues of split-particle events and particle coincidence, to study the temporal profile of individual ion clouds, and to extend the linear dynamic range by compensating for dead time related count losses.
Our latest development is an in-house built data acquisition system with nanosecond time resolution (nanoDAQ). Recording of the SEM signal by the nanoDAQ is performed on the nanosecond time scale with a dwell time of approximately 2 ns and enables detection of gold nanoparticles (AuNP) as small as 7.5 nm with a commercial single quadrupole ICP-MS instrument. [1] Analysis of acquired transient data is based on the temporal distance between detector events and a derived ion event density. It was shown that the inverse logarithm of the distance between detector events is proportional to particle size. Also, the number of detector events per particle can be used to calibrate and determine the particle number concentration (PNC) of a nanoparticle dispersion. In addition to inorganic nanoparticles, first results on the detection of microplastics with spICP-MS will be discussed.
T2 - ANAKON 2025
CY - Leipzig, Germany
DA - 10.03.2025
KW - Nano
KW - Microplastics
KW - Nanoparticle Characterization
KW - ICP-MS
KW - Instrumentation
PY - 2025
AN - OPUS4-63580
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Engelhard, Carsten
T1 - From Particles to PFAS: Recent Advances in Plasma-based Instrumentation Development
N2 - In this presentation, recent advances in plasma spectrochemistry with hot and cold plasma sources for the direct detection of nanoparticles as well as per- and polyfluoroalkyl substances (PFAS) will be discussed. In the first part, single-particle inductively coupled plasma mass spectrometry (spICP-MS) with an in-house built data acquisition system with nanosecond time resolution (nanoDAQ) will be presented. In the second part, we turn to a cooler plasma source. Specifically, a flowing atmospheric-pressure afterglow source (FAPA) and its application for the direct mass spectrometric analysis of PFAS will be discussed.
T2 - 20th European Winter Conference on Plasma Spectrochemistry
CY - Berlin, Germany
DA - 02.03.2025
KW - ICP-MS
KW - Instrumentation
KW - Nano
KW - Nanoparticle Characterization
KW - PFAS
PY - 2025
AN - OPUS4-63581
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Schmitt, Johannes
T1 - Data acquisition system for single particle inductively coupled plasma mass spectrometry (spICP-MS) with nanosecond time resolution
N2 - This study presents our data acquisition system prototype for single particle inductively coupled plasma mass spectrometry (spICP-MS) with nanosecond time resolution (nanoDAQ) and a matching data processing approach for time-resolved data in the nanosecond range. The system continuously samples the secondary electron multiplier (SEM) detector signal with a dwell time of approximately 2 ns and enables detection of gold nanoparticles (AuNP) as small as 7.5 nm with a commercial single quadrupole ICP-MS instrument. [1]
Analysis of acquired transient data is based on the temporal distance between detector events and a derived ion event density. It was shown that the inverse logarithm of the distance between detector events is proportional to particle size. Also, the number of detector events per particle can be used to calibrate and determine the particle number concentration (PNC) of a nanoparticle dispersion. [1]
Particle-by-particle-based analysis of ion event density and other parameters derived from nanosecond time resolution show promising results. High data acquisition frequency of the systems allows recording of a statistically significant number of data points in 60 s or less, which leaves only the sample uptake and rinsing steps as remaining factors for limiting the total measurement time.
T2 - ANAKON 2025
CY - Leipzig, Germany
DA - 10.03.2025
KW - ICP-MS
KW - Instrumentation
KW - Nano
KW - Nanoparticle Characterization
PY - 2025
AN - OPUS4-63603
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Rhode, Michael
T1 - Characterization of hydrogen trapping in a CoCrFeMnNi high-entropy alloy charged up to 1000 bar high-pressure hydrogen
N2 - First studies on the mechanical behavior of high-entropy alloys (HEAs) in high-pressure hydrogen environment are available. In contrast, the underlying hydrogen absorption, diffusion and trapping in these HEAs like the Cantor-alloy was less in the scientific scope so far. For that reason, the CoCrFeMnNi-HEA was compared to a conventional AISI 316L austenitic steel, by exposing to high-pressure hydrogen charging at 200 bar and very-high pressure at 1,000 bar. Thermal desorption analysis (TDA) was applied with different heating rates (0.125 K/s to 0.500 K/s), see Fig. 1a to d. The underlying TDA spectra were analyzed in terms of a reasonable peak deconvolution to into a defined number of peaks and the calculation of the activation energies for the respective and predominant hydrogen trap sites. Both materials show a comparable hydrogen diffusivity. The obtained activation energies suggest that in case of the CoCrFeMnNi-HEAs an interaction of the austenitic phase as well as the direct atomic bonding of hydrogen to the metal atoms are the dominant traps, since “impurities” such as carbides or inclusions are only present in trace amounts. Available literature suggests that the Cr and Mn-content is here of special interest for the direct hydrogen bonding at solute atoms. In addition, the trap occupancy rate must be considered in terms of a pressure-related hydrogen absorption. The derived apparent hydrogen solubility was in the order: 316L < CoCrFeMnNi-HEA for both charging pressures. Especially, the 1,000 bar values lead to noteworthy results with > 70 wt.ppm for the AISI 316L and >130 wt.ppm for the CoCrFeMnNi. In fact, both the hydrogen diffusion and trapping data on gaseous high-pressure hydrogen charged HEAs are rare so far. The results of the present study allow a deeper understanding of hydrogen trapping in the regarded CoCrFeMnNi-system.
T2 - 78th IIW Annual Assembly and International Conference
CY - Genoa, Italy
DA - 26.06.2025
KW - Hydrogen
KW - Thermal desorption analysis
KW - High-pressure charging
KW - Trapping
KW - Diffusion
PY - 2025
AN - OPUS4-63542
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Schilling, Markus
T1 - Data-Driven Materials Science: Reproducibility and Standardization
N2 - Advancing development and digitalization in materials science requires to focus on quality assurance, interoperability, and compliance with FAIR principles. Semantic technologies offer effective solutions for these challenges by enabling the storage, processing, and contextualization of data in machine-actionable and human-readable formats – essential for robust data management.
This presentation highlights the PMD Core Ontology 3.0 (PMDco 3.0), developed specifically for the field of materials science and engineering, and its implementation within generic knowledge representation frameworks. Demonstrators such as standardized mechanical testing, material processing workflows, and the Orowan Demonstrator exemplify the ontology’s practical applications. The use of graph patterns, able to be compiled into rule-based semantic shapes, supports a unified and automated approach to managing heterogeneous experimental data across domains.
T2 - Persson Group Seminar
CY - Berkeley, CA, USA
DA - 23.06.2025
KW - Semantic Data
KW - Data Integration
KW - Digitalization
KW - Data Interoperability
KW - PMD Core Ontology
KW - Graph Patterns
PY - 2025
AN - OPUS4-63484
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Pauw, Brian Richard
T1 - A place for everything: traceable science using metadata from syntheses and characterisation
N2 - In our laboratory, we rely heavily on automation for synthesis and measurement. Done right, automation can deliver reliable quantities of excruciatingly detailed data, produced in a reproducible and traceable way. This data then needs sorting and organising, and a good structure of metadata is a good start to long-lasting data.
This metadata collection is an essential part of our “holistic experimentation”-approach. In this approach, we try to ensure that all aspects of the experimental chain are performed to a high standard, so that experimental integrity is maintained. In other words: as a failure in one of the components of the chain can make an entire experiment worthless, we must ensure each component is done (and documented) well.
In this talk, we show how we 1) synthesise well-documented sample series, 2) apply a complete end-to-end X-ray scattering characterisation methodology to those samples, and 3) can link the data from the synthesis to the structural details obtained from the scattering experiments in a visual dashboard. Furthermore, we will show examples on how data can be organised in hierarchical structures in HDF5-based datafiles, and how this helps move towards more trustworthy, traceable science.
About the speaker: Brian Pauw is a full-stack X-ray scattering expert with over 15 years of experience in materials science. After earning a Ph.D. in Chemical Engineering from the Technical University of Denmark in 2009, Brian advanced scattering techniques at Japan’s National Institute for Materials Science before joining BAM (Federal Institute for Materials Research and Testing) in Germany as a permanent researcher.
At BAM, Brian focuses on small-angle scattering of polymers, metals, catalysts, and more – developing precise methodologies for data collection, correction, and analysis. They also lead efforts in laboratory automation, including robotic systems for reproducible sample preparation, aiming to enhance the efficiency and reliability of experimental workflows.
T2 - Helmholtz Metadata Collaboration: FAIR Friday Lecture Series
CY - Online meeting
DA - 09.05.2025
KW - Methodology
KW - X-ray scattering
KW - Traceability
KW - Data provenance
KW - Metadata
KW - Lab automation
KW - Holistic science
PY - 2025
AN - OPUS4-63078
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Pauw, Brian Richard
T1 - NeXus at the core of the HExX-lab
N2 - Through bottom-up, comprehensive digitalisation of all aspects of an experiment, the HEX-lab improves the trustworthiness (traceability, reproducibility, quality) of scientific findings.
The five main parts that make up a materials science experiment, i.e. Sample preparation, Measurements, Processing, Analysis, and Interpretation, each have been addressed in thorough and unique ways in this lab, building up a foundation for a wide range of materials science collaborations. Improvements span the spectrum.
Hardware developments include new sample environments and stages, such as grazing incidence motion towers, electrochemistry cells and flow-through holders, electronic components such as safety interlocks and multipurpose I/O controllers, and liquid handling systems such as coolant flow cross-over systems.
Software developments include:
1) a new comprehensive control system operating on both the RoWaN as well as the MOUSE allowing for full Python control and sequencing of all experimentation,
2) Automated scripts for instrument optimization, sample alignments and measurements,
3) revamped data pipelines and analysis software, standalone or launched as part of operations sequencing dashboards on servers, and
4) meticulously structured archival datafiles, fully documenting sample preparation, measurements, processing and analyses. These allow for holistic databases and dashboards to be constructed to investigate the links between synthesis parameters and resulting morphology.
This presentation will highlight some of the tools and techniques developed and available in the HEX-lab over the years, from sample environments to overarching experiment and data organisation structures.
T2 - Materials Science Core Facility Synergy Forum 2025
CY - Bremen, Germany
DA - 26.02.2025
KW - Digitalization
KW - Automation
KW - HDF5
KW - Traceability
KW - Data stewardship
KW - Lab automation
KW - Holistic science
KW - Methodology
PY - 2025
AN - OPUS4-62676
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Pauw, Brian Richard
T1 - Reimagining user-driven science
N2 - The materials scientists we work with do not want (or need) to learn the ways of the scatterer; they are primarily interested in obtaining trustworthy, authoritative answers. In particular, they need structural understanding in light of the wider framework of their experiment(s). Our interest, therefore, lies in helping them attain this this interconnected understanding, while using such investigations to further hone our methodology to approximate perfection.
While perfection is by definition an unattainable goal, we have spent the last 15+ years exploring and expanding on many of its constituent aspects (often together with likeminded people) [1]. These aspects include:
developing various visualization and simulation tools,
deconstructing data corrections and uncertainty estimation,
advancing analysis methods,
quantifying questions on traceability, documentation,
reproducible automation of synthesis-, measurement- and data pipelines,
data visualization, exploration and education,
and many more…
As we explored these individual aspects, it has become clear that high quality output demands involving ourselves in the entire experimental workflow, with all associated aspects. This allows you to establish trustworthy links between parameters, structure, and performance. Through multiple cross-checks and validations, we can furthermore assign a degree of confidence to our findings. This is what we call the holistic approach.
This talk will briefly define perfection in scattering experiments, expand on the holistic approach, and show examples to demonstrate its benefits.
T2 - Invited talk - special event
CY - Trieste, Italy
DA - 15.05.2025
KW - X-ray scattering
KW - Holistic experiments
KW - Laboratory management
KW - Laboratory automation
KW - Data stewardship
KW - User support
PY - 2025
AN - OPUS4-63372
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Pauw, Brian Richard
T1 - and now it's bigger…: setting up for large scale experimentation
N2 - In our laboratory, we rely heavily on automation for synthesis and measurement. Done right, automation can deliver reliable quantities of excruciatingly detailed data, produced in a reproducible and traceable way. This data then needs sorting and organising, and a good structure of metadata is a good start to long-lasting data.
This metadata collection is an essential part of our “holistic experimentation”-approach. In this approach, we try to ensure that all aspects of the experimental chain are performed to a high standard, so that experimental integrity is maintained. In other words: as a failure in one of the components of the chain can make an entire experiment worthless, we must ensure each component is done (and documented) well.
In this talk, we show how we 1) synthesise well-documented sample series, 2) apply a complete end-to-end X-ray scattering characterisation methodology to those samples, and 3) can link the data from the synthesis to the structural details obtained from the scattering experiments in a visual dashboard. Furthermore, we will show examples on how data can be organised in hierarchical structures in HDF5-based datafiles, and how this helps move towards more trustworthy, traceable science.
T2 - Future Labs Live 2025
CY - Basel, Switzerland
DA - 27.05.2025
KW - Lab automation
KW - Holistic experiments
KW - Synthesis
KW - Traceability
KW - Data stewardship
PY - 2025
AN - OPUS4-63373
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Monroy, José del Refugio
A1 - Deshpande, Tejas
A1 - Schlecht, Joël
A1 - Douglas, Clara
A1 - Stirling, Robbie
A1 - Grabicki, Niklas
A1 - Smales, Glen Jacob
A1 - Kochovski, Zdravko
A1 - Fabozzi, Filippo Giovanni
A1 - Hecht, Stefan
A1 - Feldmann, Sascha
A1 - Dumele, Oliver
T1 - Homochiral versus racemic 2D covalent organic frameworks
N2 - The synthesis of homochiral two-dimensional covalent organic frameworks (2D COFs) from chiral π-conjugated building blocks is challenging, as chiral units often lead to misaligned stacking interactions. In this work, we introduce helical chirality into 2D COFs using configurationally stable enantiopure and racemic [5]helicenes as linkers in the backbone of 2D [5]HeliCOFs as powders and films. Through condensation with 1,3,5-triformylbenzene (TFB) or 1,3,5-triformylphloroglucinol (TFP), our approach enables the efficient formation of a set of homochiral and racemic 2D [5]HeliCOFs. The resulting carbon-based crystalline and porous frameworks exhibit distinct structural features and different properties between homochiral and racemic counterparts. Propagation of helical chirality into the backbone of the crystalline frameworks leads to the observation of advanced chiroptical properties in the far-red visible spectrum, along with a less compact structure compared with the racemic frameworks. Homogeneous thin films of [5]HeliCOFs disclosed photoluminescent properties arising from the controlled growth of highly ordered π-conjugated lattices. The present study offers insight into general chiral framework formation and extends the Liebisch−Wallach rule to 2D COFs.
KW - Chirality
KW - Covalent organic frameworks
KW - Diffraction
KW - Lattices
KW - Thin films
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-633755
DO - https://doi.org/10.1021/jacs.5c01004
SN - 0002-7863
VL - 147
IS - 21
SP - 17750
EP - 17763
PB - American Chemical Society (ACS)
CY - Washington, DC
AN - OPUS4-63375
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Khropost, Diana
A1 - Riethmüller, Franziska
A1 - Döhring, Thorsten
A1 - Flachs, Dennis
A1 - Hülagü, Deniz
A1 - Hertwig, Andreas
A1 - Cotroneo, Vincenzo
A1 - gibertini, eugenio
T1 - Polydopamine – a bio-inspired polymer for X-ray mirror coatings and other technical applications
N2 - Although the organic molecule dopamine (3,4-dihydroxyphenethylamine) is commonly known as one of the “hormones of happiness”, thin polymer films of polydopamine (PDA) also have interesting technical properties. PDA is a very strong glue that sticks on almost everything, even under water. In nature, PDA is found in the byssal thread cuticles of mussels. When produced by dip-coating, the self-organizing PDA layers grow in a reproducible thickness of single or multiple molecule monolayers of a few nanometres thickness only. Here we present an optimized preparation regime as derived from polymerization analysis through absorption spectroscopy. One application is the use of thin PDA overcoatings to increase the soft X-ray reflectivity of astronomical X-ray mirrors. Furthermore, we give an outlook to other technical applications for this interesting material, presenting this bio-inspired organic polymer as an innovative technical solution for the future, with applications such as PDA-based super-capacitors and its promising role in enhancing separator materials for batteries.
T2 - SPIE Optics + Optoelectronics 2025
CY - Prague, Czech Republic
DA - 07.04.2025
KW - X-ray mirrors
KW - Reflectivity
KW - Polydopamine
KW - Ellipsometry
PY - 2025
DO - https://doi.org/10.1117/12.3056298
VL - 13531
SP - 1
EP - 11
PB - SPIE
AN - OPUS4-63630
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Khropost, Diana
A1 - Riethmüller, Franziska
A1 - Stanik, Eva
A1 - Döhring, Thorsten
A1 - Hertwig, Andreas
A1 - Hülagü, Deniz
T1 - Polydopamine -a bionic material and its potential applications for batteries
N2 - Polydopamine (PDA) recently came into focus as an innovative material for applications in various technical fields. It is a very strong glue that sticks on almost everything, even under water: In nature, PDA is found in the byssal thread cuticles of mussels. In 2007, Lee et al. first showed that dipping substrates into a solution of dopamine results in the formation of thin PDA films on numerous materials. The simple preparation and the high durability of these coatings have stimulated growing research interest and a wide variety of applications in energy, biomedical and environmental science, and other fields.
We have investigated thin layers of PDA with different methods including ellipsometry, tactile measurements of the layer thickness and in situ absorption measurements during the polymerization process. During polymerization the dopamine solution shows a progressive colour change from transparent to brown that has been monitored by spectrometric measurements. The increasing absorption of the cuvette with dopamine solution can be seen in figure 1. The absorption levels off after approximately 2,5 h of polymerization time, thus indicating termination of the primary formation of the PDA film. This data shows that for homogeneous layer growth it is advantageous to interrupt the process after two hours. To generate a higher layer thickness, the samples need to be cleaned and immersed in a fresh dopamine solution subsequently. In addition, ellipsometry measurements on polydopamine layers could determine the corresponding coating thickness as well as its complex refractive index over a broad wavelength range.
T2 - Materials Week 2025
CY - Frankfurt am Main, Germany
DA - 02.04.2025
KW - Polydopamine
KW - Ellipsometry
KW - Leyer thickness
PY - 2025
AN - OPUS4-63636
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Mangarova, Dilyana B.
A1 - Kaufmann, Jan O.
A1 - Brangsch, Julia
A1 - Kader, Avan
A1 - Möckel, Jana
A1 - Heyl, Jennifer L.
A1 - Verlemann, Christine
A1 - Adams, Lisa C.
A1 - Ludwig, Antje
A1 - Reimann, Carolin
A1 - Poller, Wolfram C.
A1 - Niehaus, Peter
A1 - Karst, Uwe
A1 - Taupitz, Matthias
A1 - Hamm, Bernd
A1 - Weller, Michael G.
A1 - Makowski, Marcus R.
T1 - ADAMTS4-Specific MR Peptide Probe for the Assessment of Atherosclerotic Plaque Burden in a Mouse Model
N2 - Introduction
Atherosclerosis is the underlying cause of multiple cardiovascular pathologies. The present-day clinical imaging modalities do not offer sufficient information on plaque composition or rupture risk. A disintegrin and metalloproteinase with thrombospondin motifs 4 (ADAMTS4) is a strongly upregulated proteoglycan-cleaving enzyme that is specific to cardiovascular diseases, inter alia, atherosclerosis.
Materials and Methods
Male apolipoprotein E-deficient mice received a high-fat diet for 2 (n = 11) or 4 months (n = 11). Additionally, a group (n = 11) receiving pravastatin by drinking water for 4 months alongside the high-fat diet was examined. The control group (n = 10) consisted of C57BL/6J mice on standard chow. Molecular magnetic resonance imaging was performed prior to and after administration of the gadolinium (Gd)-based ADAMTS4-specific probe, followed by ex vivo analyses of the aortic arch, brachiocephalic arteries, and carotid arteries. A P value <0.05 was considered to indicate a statistically significant difference.
Results
With advancing atherosclerosis, a significant increase in the contrast-to-noise ratio was measured after intravenous application of the probe (mean precontrast = 2.25; mean postcontrast = 11.47, P < 0.001 in the 4-month group). The pravastatin group presented decreased ADAMTS4 expression. A strong correlation between ADAMTS4 content measured via immunofluorescence staining and an increase in the contrast-to-noise ratio was detected (R2 = 0.69). Microdissection analysis revealed that ADAMTS4 gene expression in the plaque area was significantly greater than that in the arterial wall of a control mouse (P < 0.001). Laser ablation–inductively coupled plasma–mass spectrometry confirmed strong colocalization of areas positive for ADAMTS4 and Gd.
Conclusions
Magnetic resonance imaging using an ADAMTS4-specific agent is a promising method for characterizing atherosclerotic plaques and could improve plaque assessment in the diagnosis and treatment of atherosclerosis.
N2 - Einleitung
Atherosklerose ist die Ursache für zahlreiche Herz-Kreislauf-Erkrankungen. Die derzeitigen klinischen Bildgebungsverfahren liefern keine ausreichenden Informationen über die Zusammensetzung von Plaques oder das Risiko einer Ruptur. A Disintegrin and Metalloproteinase with Thrombospondin Motifs 4 (ADAMTS4) ist ein stark hochreguliertes Proteoglykan-spaltendes Enzym, das unter anderem bei Herz-Kreislauf-Erkrankungen wie Atherosklerose spezifisch auftritt.
Materialien und Methoden
Männliche Apolipoprotein-E-defiziente Mäuse erhielten 2 (n = 11) oder 4 Monate lang (n = 11) eine fettreiche Ernährung. Zusätzlich wurde eine Gruppe (n = 11) untersucht, die 4 Monate lang neben der fettreichen Ernährung Pravastatin über das Trinkwasser erhielt. Die Kontrollgruppe (n = 10) bestand aus C57BL/6J-Mäusen, die mit Standardfutter ernährt wurden. Vor und nach der Verabreichung der gadolinium (Gd)-basierten ADAMTS4-spezifischen Sonde wurde eine molekulare Magnetresonanztomographie durchgeführt, gefolgt von Ex-vivo-Analysen des Aortenbogens, der Arteria brachiocephalica und der Arteria carotis. Ein P-Wert < 0,05 wurde als statistisch signifikanter Unterschied gewertet.
Ergebnisse
Mit fortschreitender Atherosklerose wurde nach intravenöser Anwendung der Sonde ein signifikanter Anstieg des Kontrast-Rausch-Verhältnisses gemessen (Mittelwert vor Kontrastmittelgabe = 2,25; Mittelwert nach Kontrastmittelgabe = 11,47, P < 0,001 in der 4-Monats-Gruppe). Die Pravastatin-Gruppe zeigte eine verminderte ADAMTS4-Expression. Es wurde eine starke Korrelation zwischen dem mittels Immunfluoreszenzfärbung gemessenen ADAMTS4-Gehalt und einem Anstieg des Kontrast-Rausch-Verhältnisses festgestellt (R2 = 0,69). Die Mikrodissektionsanalyse ergab, dass die ADAMTS4-Genexpression im Plaque-Bereich signifikant höher war als in der Arterienwand einer Kontrollmaus (P < 0,001). Laserablation-induktiv gekoppelte Plasma-Massenspektrometrie bestätigte eine starke Kolokalisierung von ADAMTS4- und Gd-positiven Bereichen.
Schlussfolgerungen
Die Magnetresonanztomographie mit einem ADAMTS4-spezifischen Kontrastmittel ist eine vielversprechende Methode zur Charakterisierung atherosklerotischer Plaques und könnte die Plaquebewertung in der Diagnose und Behandlung von Atherosklerose verbessern.
KW - Peptide Aptamer
KW - MRI Probe
KW - Magnetic resonance imaging (MRI)
KW - Peptide libraries
KW - Laser ablation–inductively coupled plasma–mass spectrometry
KW - ICP MS
KW - Imaging
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-635832
DO - https://doi.org/10.1097/RLI.0000000000001152
SN - 1536-0210
VL - 60
IS - 8
SP - 499
EP - 507
PB - Ovid Technologies (Wolters Kluwer Health)
CY - Philadelphia, Pennsylvania, USA
AN - OPUS4-63583
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Nikitin, D.
A1 - Biliak, K.
A1 - Protsak, M.
A1 - Adejube, B.
A1 - Ali-Ogly, S.
A1 - Škorvanková, K.
A1 - Červenková, V.
A1 - Katuta, R.
A1 - Tosco, M.
A1 - Hanuš, J.
A1 - Černochová, Z.
A1 - Černoch, P.
A1 - Štěpánek, P.
A1 - Boiko, O.
A1 - Szymoniak, Paulina
A1 - Schönhals, Andreas
A1 - Faupel, F.
A1 - Biedermann, H.
A1 - Vahl, A.
A1 - Choukourov, A.
T1 - Unveiling the Fundamental Principles of Reconfigurable Resistance States in Silver/Poly(ethylene glycol) Nanofluids
N2 - Developing novel memristive systems aims to implement key principles of biological neuron assemblies – plasticity, adaptivity, and self-organization – into artificial devices for parallel, energy-efficient computing. Solid-state memristive devices, such as crossbar arrays and percolated nanoparticle (NP) networks, already demonstrate these properties. However, closer similarity to neural networks is expected from liquid-state systems, including polymer melts, which remain largely unexplored. Here, the resistive switching in silver/poly(ethylene glycol) (Ag/PEG) nanofluids, prepared by depositing gas-aggregated Ag NPs into PEGs of varying molecular mass, is investigated.
These systems form long-range conductive NP bridges with reconfigurable resistance states in response to an electric field. The zeta-potential of Ag NPs and molecular mobility of PEG determine the prevalence of low resistance (ohmic) state, high resistance states (poor conductance) or intermediate transition states governed by space-charge-limited conduction or electron tunneling. The occurrence of these states is given by the interparticle gaps, which are determined by the conformation of PEG molecules adsorbed on the NPs. It is presented, for the first time, an equivalent circuit model for the Ag/PEG system. These findings pave the way to adopt polymer melts as matrices for neuromorphic engineering and bio-inspired electronics.
KW - Nanofluids
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-635351
DO - https://doi.org/10.1002/advs.202505103
VL - 12
SP - 1
EP - 14
PB - Wiley
AN - OPUS4-63535
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Schlögl, Johanna
A1 - Krappe, Alexander R.
A1 - Fürstenwerth, Paul C.
A1 - Brosius, Amelie L.
A1 - Fasting, Carlo
A1 - Hoffmann, Kurt F.
A1 - Resch-Genger, Ute
A1 - Eigler, Siegfried
A1 - Steinhauer, Simon
A1 - Riedel, Sebastian
T1 - Luminescent Perhalofluoro Trityl Radicals
N2 - In this proof-of-concept study, we show that polyfluorinated trityl radicals with the, to this date, highest fluorination grade can be accessed in quantitative yields in a straightforward manner starting from the perfluorinated trityl cation. The trityl skeleton is functionalized with trimethylsilyl halides to yield perhalofluoro trityl cations, which are subsequently reduced using commercial zinc powder. In this way, we prepare three perhalofluoro trityl radicals and analyze the impact of the fluorine ligands on their electro-optical properties, revealing some interesting trends. In comparison to literature-known polychlorinated trityl radicals, the new polyfluorinated derivatives exhibit substantially higher fluorescence quantum yields, longer luminescence lifetimes, and an expanded emission range that extends into the yellow spectral region. They further display enhanced photostability under light irradiation. In radical-stained polystyrene nanoparticles, an additional broad emission band in the red−NIR wavelength region is observed, which is attributed to excimer formation. Finally, the stability of the new radicals is investigated under ambient conditions, showing the slow conversion with atmospheric oxygen yielding the respective peroxides, which are characterized by single-crystal X-ray diffraction. All in all, our study extends the present scope of luminescent trityl radicals, as the functionalization of the perfluorinated cationic precursor unlocks the path toward a vast variety of polyfluorinated trityl radicals.
KW - Dye
KW - Fluorescence
KW - Radical
KW - Synthesis
KW - Mechanism
KW - Signal enhancement
KW - Nano
KW - Particle
KW - Characterization
KW - Quantum yield
KW - Photophysics
KW - Lifetime
KW - Polarity
KW - Polymer
KW - Solvatchromism
KW - Excimer
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-647973
DO - https://doi.org/10.1021/jacs.5c16418
SN - 0002-7863
VL - 147
IS - 46
SP - 1
EP - 8
PB - American Chemical Society (ACS)
AN - OPUS4-64797
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - GEN
A1 - Resch-Genger, Ute
A1 - Abram, Sarah-Luise
A1 - Tavernaro, Isabella
A1 - Zou, Shan
A1 - Johnston, Linda
T1 - Behind the Paper: Nanoscale Reference and Test Materials for the Validation of Characterization Methods for Engineered Nanomaterials – Current State, Limitations and Needs
N2 - Engineered nanomaterials (NMs) of different material composition, morphology, and surface chemistry are widely used in material and life sciences. For NM quality control and risk assessment, NM key properties must be characterized with validated methods, requiring reference materials (RMs).
KW - Engineered Nanomaterials
KW - Nanoscale reference materials
KW - Interlaboratory comparisons
KW - Traceability
KW - Standardization and Regulation
KW - Nano
KW - Particle
KW - Quality assurance
KW - Surface chemistry
PY - 2025
UR - https://communities.springernature.com/posts/nanoscale-reference-and-test-materials-for-the-validation-of-characterization-methods-for-engineered-nanomaterials-current-state-limitations-and-needs
SP - 1
EP - 3
PB - Springer Nature
CY - Online
AN - OPUS4-62572
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Haroun, A. A. A.
A1 - Derbala, H. A.
A1 - Bassioni, G.
A1 - Resch-Genger, Ute
A1 - Shafik, E. S.
A1 - Hassan, A. M. A.
T1 - N-aminophthalimide as a novel UV-stabilizer to promote physico-mechanical properties of highdensity polyethylene (HDPE)
N2 - This study aimed to evaluate the efficacy of Naminophthalimide (NAP) as a novel UV-stabilizer for highdensity polyethylene (HDPE) in improving its physicomechanical properties under UV exposure. NAP was synthesized by interaction between phthalimide and hydrazine hydrate. It was incorporated into HDPE with different weight ratios (1, 1.5, 2, and 3%), and its performancewas compared with Hostavin as a traditional UV stabilizer. The HDPE composites were exposed to UV irradiation for different periods (7 and 14 days) to evaluate their photodegradation behavior. Tensile strength, elongation at break were assessed before and after UV exposure. Also, oxidation induction time (OIT), melt flow rate (MFR), Vicat softening temperature were evaluated. Hostavin incorporation reduced tensile strength from 22.36 to 20.62MPa at higher concentrations. It has been found that 3% Hostavin, significantly improved elongation at break, increasing from 423% to 1,170%, suggesting enhanced flexibility. In contrast, NAP increased tensile strength to 22.9MPa and moderately enhanced elongation but slightly declined at 3%due to potential over-stabilization. Under UV exposure, retained tensile strength and elongation was improved with stabilizer content, which increasing tensile strength retention. The HDPE that containing NAP showed enhanced UV resistance and superior retention of mechanical properties compared to Hostavin.
KW - Polymer
KW - Advanced materials
KW - Quality assurance
KW - Stabilizer
KW - Synthesis
KW - Physico-mechanical properties
PY - 2025
DO - https://doi.org/10.1515/polyeng-2024-0262
SN - 2191-0340
SP - 1
EP - 8
PB - De Gruyter
CY - Berlin
AN - OPUS4-63534
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Resch-Genger, Ute
T1 - Reliable Photoluminescence Quantum Yields – New Reference Materials and Interlaboratory Comparisons
N2 - The rational design and choice of molecular and nanoscale reporters, the comparison of different emitter classes, and photophysical and mechanistic studies require quantitative photoluminescence measurements and the reliable determination of the key performance parameter photoluminescence quantum yield (QY), i.e., the number of emitted per absorbed photons. This is of special importance for all photoluminescence applications in the life and material sciences in the UV/vis/NIR/SWIR. To improve the reliability and comparability of photoluminescence and QY measurements across laboratories, pitfalls, achievable uncertainties, and material-specific effects related to certain emitter classes must be explored. Also, suitable protocols and reference materials are needed which have been validated in interlaboratory comparisons for different wavelength regions and transparent and scattering luminophores.[1]
Based on absolute and relative photoluminescence measurements of functional dyes and luminescent nanomaterials, reliable methods for determining QY of transparent and scattering luminophores, nonlinear emitters, and solid luminescent nanomaterials have been developed.[1-4] Thereby, material- and method-related uncertainties of relative and absolute QY measurements and achievable uncertainties could be quantified for linear and nonlinear UV/vis/NIR/SWIR emitters and lately for also luminescent and scattering materials and solid phoshors.
In this context, we present the development and certification of a first set of UV/vis/NIR quantum yield standards with a complete uncertainty budget,[5] which present simple tools for a better comparability of QY measurements. In addition, a first interlaboratory comparison of absolute QY measurements of solid and scattering LED converter materials with integrating sphere spectroscopy has been performed.[5] The outcome of this study is presented, thereby addressing common pitfalls and measurement uncertainties and providing recommendations for the performance of reliable QY measurements of linear and non-linear emitters in transparent, scattering, and solid samples.
T2 - Anakon 2025
CY - Leipzig, Germany
DA - 10.03.2025
KW - Quality assurance
KW - Reference material
KW - Method
KW - Fluorescence
KW - Quantum yield
KW - Absolute
KW - Integrating sphere spectroscopy
KW - Interlaboratory comparison
KW - Dye
KW - Film
KW - Nano
KW - Particle
KW - Scattering
KW - Uncertainty
KW - LED converter
PY - 2025
AN - OPUS4-62792
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Osiopova, Viktoriia
A1 - Tavernaro, Isabella
A1 - Ge, L.
A1 - Kitzmann, W. R.
A1 - Heinze, K.
A1 - Reithofer, M. R.
A1 - Resch-Genger, Ute
T1 - Complete protection of NIR-luminescent molecular rubies from oxygen quenching in air by L-arginine-mediated silica nanoparticles
N2 - The application of emerging luminophores such as near-infrared (NIR) emissive complexes based on earth-abundant chromium as central ion and triplet-triplet annihilation upconversion (TTA-UC) systems in air as optical reporters for bioimaging or photonic materials for energy conversion requires simple and efficient strategies for their complete protection from uminescence quenching by oxygen. Therefore, we explored the influence of sol–gel synthesis routes on the oxygen protection efficiency of the resulting core and core/shell silica nanoparticles (SiO2 NPs), utilizing the molecular ruby-type luminophores CrPF6 ([Cr(ddpd)2](PF6)3; ddpd = N,N'-dimethyl-N,N'-dipyridin-2-ylpyridin-2,6-diamine) and CrBF4 ([Cr(ddpd)2](BF4)3) with their oxygendependent, but polarity-, proticity-, viscosity-, and concentration-independent luminescence as optical probes for oxygen permeability. The sol–gel chemistry routes we assessed include the classical Stöber method and the underexplored Larginine approach, which relies on the controlled hydrolysis of tetraethoxysilane (TEOS) in a biphasic cyclohexane/water system with the catalyst L-arginine. As demonstrated by luminescence measurements of air- and argon-saturated dispersions of CrPF6- and CrBF4-stained SiO2 NPs of different size and particle architecture, utilizing the luminescence decay kinetics of argon-saturated solutions of CrPF6 and CrBF4 in acetonitrile (ACN) as benchmarks, only SiO2 NPs or shells synthesized by the L-arginine approach provided complete oxygen protection of the CrIII complexes under ambient conditions. We ascribe the different oxygen shielding efficiencies of the silica networks explored to differences in density and surface chemistry of the resulting nanomaterials and coatings, leading to different oxygen permeabilities. Our Larginine based silica encapsulation strategy can open the door for the efficient usage of oxygen-sensitive luminophores and TTA-UC systems as optical reporters and spectral shifters in air in the future.
KW - Quality assurance
KW - Fluorescence
KW - Quantification
KW - Advanced materials
KW - Nano
KW - Quantum yield
KW - NIR
KW - Characterization
KW - Electron microscopy
KW - Silica
KW - Synthesis
KW - Oxygen sensing
KW - Surface
KW - Doping
KW - Lifetime
KW - Cr(III) complex
KW - Shielding
KW - Sensing
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-638271
DO - https://doi.org/10.26599/NR.2025.94907241
SN - 1998-0000
VL - 18
IS - 3
SP - 1
EP - 13
PB - SciOpen
AN - OPUS4-63827
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Resch-Genger, Ute
T1 - Reliable measurements of the photoluminescence quantum yield of transparent and scattering luminophores
N2 - Optical measurements of transparent solutions of organic dyes and semiconductor quantum dots and scattering materials such as luminescent nanocomposites and microparticles and phosphors dispersed in liquid and solid matrices play an important role in energy conversion, solid-state lighting, medical diagnostics, and security barcoding. A key performance parameter is the photoluminescence quantum yield QY, i.e., the number of emitted per number of absorbed photons. QY of transparent luminophore solutions can be obtained relative to a fluorescence QY standard of known QY.[1] Meanwhile, a first set of certified fluorescence QY standards is available.[2] Such relative QY measurements require a calibrated spectrofluorometer.[1,3] For determining QY of scattering liquid and solid samples, absolute measurements of QY with a calibrated integrating sphere setup are mandatory.[1,4,5] However, scattering QY standards are not available and uncertainties of such measurements have not yet been assessed in interlaboratory comparisons (ILCs).
To determine typical sources of uncertainty of absolute QY measurements, we assessed the influence of the measurement geometry and the optical properties of the blank for determining the number of incident photons absorbed by the sample in an ILC using commercial integrating sphere setups and a custom-designed integrating sphere setup. Samples examined included transparent and scattering dye solutions, solid phosphors such as YAG:Ce optoceramics used as LED converter material, and polymer films stained with different amounts of phosphor microparticles. Matching QY values could be obtained for transparent dye solutions and scattering dispersions with a blank with scattering properties closely matching those of the sample, while QY measurements of optoceramic samples with different blanks revealed substantial differences of more than 20 %. Based on our data, we recommend non-absorbing blank materials with a high reflectivity (>95 %) such as a 2 mm-thick PTFE target placed on the sample holder as blanks.
T2 - eMRS 2025 Fall Meeting
CY - Warsaw, Poland
DA - 15.09.2025
KW - Quality assurance
KW - Fluorescence
KW - Nano
KW - Particle
KW - Advanced material
KW - Synthesis
KW - Characterization
KW - Fluorescence quantum yield
KW - Phosphor
KW - Absolute
KW - Integrating sphere spectroscopy
KW - Dye
KW - Standardization
KW - Reference material
KW - Interlaboratory comparison
KW - Uncertainty
PY - 2025
AN - OPUS4-64184
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Soyka, J. P.
A1 - Witte, J. F.
A1 - Wiesner, A.
A1 - Krappe, A. R.
A1 - Wehner, D.
A1 - Alnicola, N.
A1 - Paulus, B.
A1 - Resch-Genger, Ute
A1 - Eigler, S.
T1 - [3]Radialene Fluorophores with pH-Switchable Emission and Stable Absorption Maxima
N2 - The first push–pull quino [3]radialene fluorescent dye is reported. Herein, the novel bis(dicyanomethylene)-[3]radialene electron acceptor is connected to a benzimidazole donor. With protonation, a substantial redshift of fluorescence wavelength is observed, while the absorption maximum remains stable. This process is accompanied with an increased fluorescence quantum yield to about 70%. Further, the findings are explained by a combined experimental and theoretical approach, and it is found that vibronic coupling plays a crucial role. This study highlights the yet unexplored potential of [3]radialene-based motifs for the design of environment-responsive fluorophores.
KW - DADQ
KW - Nanographene
KW - fluorescence
KW - Nano
KW - Particle
KW - Synthesis
KW - Characterization
KW - Advanced material
KW - Quantum yield
KW - Photophysic
KW - pH
KW - Probe
KW - Sensor
KW - Lifetime
KW - Polarity
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-642147
DO - https://doi.org/10.1002/ejoc.202500669
SN - 1099-0690
SP - 1
EP - 6
PB - Wiley-VCH
CY - Weinheim
AN - OPUS4-64214
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Weinel, Kristina
A1 - Hahn, Marc Benjamin
A1 - Lubk, Axel
A1 - González Martínez, Ignacio Guillermo
A1 - Büchner, Bernd
A1 - Agudo Jácome, Leonardo
T1 - Nanoparticle Synthesis by Precursor Irradiation with Low-Energy Electrons
N2 - Nanoparticles (NPs) and their fabrication routes are intensely studied for their wide range of application in optics, chemistry, and medicine. Γ-ray and ion irradiation of precursor matter are established methods that facilitate tailored NP synthesis without complicated chemistry. Here, we develop and explore NP synthesis based on irradiating precursor microparticles with low-energy electron beams. We specifically demonstrate the fabrication of plasmonic gold nanoparticles of sizes between 3 and 350 nm on an amorphous SiOx substrate using a 30 kV electron beam. By detailed comparison with electron scattering simulations and thermodynamic modeling, we reveal the dominant role of inelastic electron–matter interaction and subsequent localized heating for the observed vaporization of the precursor gold microparticles. This general principle suggests the suitability of electron-beam irradiation for synthesizing NPs of a wide class of materials.
KW - Gold Nanoparticle
KW - Scanning Electron Microscopy
KW - In situ irradiation
KW - Thermodynamic modelling
KW - Heat Transfer
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-627609
DO - https://doi.org/10.1021/acsanm.4c06033
SN - 2574-0970
VL - 8
IS - 10
SP - 4980
EP - 4988
PB - ACS Publications
CY - Washington, DC
AN - OPUS4-62760
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Feng, Wen
A1 - Schulz, Johannes
A1 - Wolf, Daniel
A1 - Pylypenko, Sergii
A1 - Gemming, Thomas
A1 - Weinel, Kristina
A1 - Agudo Jácome, Leonardo
A1 - Büchner, Bernd
A1 - Lubk, Axel
T1 - Secondary electron emission from gold microparticles in a transmission electron microscope: comparison of Monte Carlo simulations with experimental results
N2 - We measure the electron beam-induced current to analyze the electron-induced secondary electron (SE) emission from micron-sized gold particles illuminated by 80 and 300 keV electrons in a transmission electron microscope. A direct comparison of the experimental and simulated SE emission (SEE) employing Monte Carlo scattering simulations based on the GEANT4 toolkit yields overall good agreement with a noticeable discrepancy arising from the shortcoming of the GEANT4 scattering cross sections in the low-loss regime. Thus, the electron beam-induced current analysis allows to quantify the inelastic scattering including SEE in the transmission electron microscope and provides further insight into the charging mechanisms.
KW - Electron beam-induced current
KW - Transmission electron microscopy
KW - Secondary electron emission
KW - Secondary electron yield
KW - Gold micronoparticle
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-622557
DO - https://doi.org/10.1088/1361-6463/ad9840
VL - 58
IS - 8
SP - 1
EP - 7
PB - IOP Publishing
CY - Bristol, GB
AN - OPUS4-62255
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Agudo Jácome, Leonardo
T1 - In situ electron-beam 'melting' (sublimation) of gold microparticles in the SEM
N2 - Gold micro particles have been modified in the past using the high power density of a localized electron beam of acceleration voltages above 100 kV as an energy source to transform matter at the sub-micron scale in a transmission electron microscope uses. Here, the e-beam-induced transformation of precursor microparticles employing a low-energy e-beam with an acceleration voltage of 30 kV in a scanning electron microscope is implemented. Under these conditions, the technique can be classified between e-beam lithography, where the e-beam is used to mill holes in or grow some different material onto a substrate, and e-beam welding, where matter can be welded together when overcoming the melting phase. Modifying gold microparticles on an amorphous SiOx substrate reveals the dominant role of inelastic electron-matter interaction and subsequent localized heating for the observed melting and vaporization of the precursor microparticles under the electron beam. Monte-Carlo scattering simulations and thermodynamic modeling further support the findings.
T2 - IKZ International Fellowship Award & Summer School 2025 from May 5 to 7, 2025
CY - Berlin, Germany
DA - 05.05.2025
KW - Gold Nanoparticle
KW - Scanning Electron Microscopy
KW - In situ irradiation
KW - Thermodynamic modelling
KW - Heat Transfer
PY - 2025
AN - OPUS4-63256
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Andresen, Elina
T1 - Towards Development of Reference Test Materials for Metrology in Nanomedicine
N2 - The EPM-project “MetrINo” responds to the immediate metrological needs expressed by industry, regulators and policy makers for the development and validation of traceable measurement methods and reference materials (RMs) candidates for the assessment of CQAs of nanotherapeutics. The conference talk focuses on the preparation, homogeneity and stability studies of iron oxide and multi-element nanoparticles as candidate reference materials for size measurements. The developed materials aim to support the development and harmonization of traceable methodologies for nanoparticle characterization.
T2 - NME 2025
CY - Barcelona, Spain
DA - 27.05.2025
KW - IONPs
KW - Reference materials
KW - Lanthanide-based upconverting nanoparticles
PY - 2025
AN - OPUS4-63905
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Abram, Sarah-Luise
A1 - Tavernaro, Isabella
A1 - Resch-Genger, Ute
A1 - Johnston, L. J.
A1 - Zou, S.
T1 - Nanoscale reference and test materials for the validation of characterization methods for engineered nanomaterials — current state, limitations, and needs
N2 - The rational design of engineered nanomaterials (NMs) with improved functionality and their increasing industrial application requires reliable, validated, and ultimately standardized characterization methods for their application-relevant, physicochemical key properties such as size, size distribution, shape, or surface chemistry. This calls for nanoscale (certified)
reference materials (CRMs; RMs) and well-characterized reference test materials (RTMs) termed also quality control (QC) samples, assessed, e.g., in interlaboratory comparisons, for the validation and standardization of commonly used characterization methods. Thereby, increasing concerns regarding potential risks of NMs are also addressed and the road for safe and
sustainable-by-design concepts for the development of new functional NMs and their use as nanomedicines is paved. With this respect, we will provide an overview of relevant international standardization and regulatory activities, definitions, and recommendations on characterization methods and review currently available organic or inorganic nanoscale CRMs, RMs, and RTMs, including their characterization or certification. In addition, we will highlight typical applications to streamline the regulatory approval process and improve manufacturability including the special challenges imposed by the colloidal nature and sometimes limited stability of NMs. Subsequently, we will critically assess the limitations of currently available nanoscale RMs and RTMs and address the gaps to be filled in the future such as the availability of NMs that come with reference data on properties other than commonly addressed particle size, such as surface chemistry or particle number concentration, or
more closely resemble commercially available formulations or address application-relevant matrices.
KW - Nano
KW - Particle
KW - Silica
KW - Quality assurance
KW - Reference material
KW - Review
KW - Surface chemistry
KW - Size
KW - Shape
KW - Particle number concentration
KW - Lipid nanoparticles
KW - Metal nanoparticles
KW - Liposomes
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-625746
DO - https://doi.org/10.1007/s00216-024-05719-6
SN - 1618-2650
SP - 1
EP - 21
PB - Springer
AN - OPUS4-62574
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Resch-Genger, Ute
T1 - Career Options in Public Service
N2 - In the following, an overview of possible career options for chemists is presented covering metrology institutes, departmental research institutes of ministries, Federal and state research institutes and options in areas such as Federal or state institutions in charge of occupational safety, the German armed forces, wastewater treatment plants and labs/institutes controlling water quality, and museums. Thereby also examples and personal insights of the daily work routine are provided for some employers.
T2 - Career-Workshop ChiÖD
CY - Karlsruhe, Germany
DA - 02.04.2025
KW - Quality assurance
KW - Reference analysis
KW - Standardization
KW - Metrology
KW - Reference products
KW - Reference materials
KW - Mission
PY - 2025
AN - OPUS4-62867
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Resch-Genger, Ute
T1 - From molecular and nanoscale chromophores with UV/VIS/NIR/SWIR luminescence to multi method characterization of surface coatings
N2 - An overview of the research activities of division Biophotonics is presented covering examples for photophysical studies of different types of molecular and nanocrystalline luminophores, luminescent particles, and sensor systems in solution, in dispersion, and in the solid state and multi-method charactreization workflow for the characterization of surface-functionalized engineered nanomaterials. In addition, the importance of reliable optical measurements, particularly standardized workflows for the determination of the key performance parameter luminescence quantum yield of transparent and scattering luminescent samples with fluorescence and integrating sphere spectroscopy, and validated methods for quantifying surface functional groups and ligands on nanomaterials is highlighted. Thereby, also ongoing standardization activities are presented as well as certified reference materials and reference materials from division Biophotonics.
T2 - Chinese-German Chemical Association - Annual Meeting
CY - Berlin, Germany
DA - 22.08.2025
KW - Quality assurance
KW - Fluorescence
KW - Nano
KW - Particle
KW - Synthesis
KW - Quantum yield
KW - Characterization
KW - Advanced material
KW - Surface
KW - Lifetime
KW - Sensor
KW - Oxygen
KW - Ph
KW - Standardization
KW - Fluorescent probe
KW - Reference material
PY - 2025
AN - OPUS4-64181
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Tavernaro, Isabella
A1 - Sander, P. C.
A1 - Andresen, Elina
A1 - Schedler, U.
A1 - Resch-Genger, Ute
T1 - Expanding the Toolbox of Simple, Cost-Efficient, and Automatable Methods for Quantifying Surface Functional Groups on Nanoparticles� Potentiometric Titration
N2 - Measuring surface functional groups (FGs) on nanomaterials (NMs) is essential for designing dispersible and stable NMs with tailored and predictable functionality. FG screening and quantification also plays a critical role for subsequent processing steps, NM long-term stability, quality control of NM production, and risk assessment studies and enables the implementation of sustainable and safe(r)-by-design concepts. This calls for simple and cost-efficient methods for broadly utilized FGs that can be ideally automated to speed up FG screening, monitoring, and quantification. To expand our NM surface analysis toolbox, focusing on simple methods and broadly available, cost-efficient instrumentation, we explored a NM-adapted pH titration method with potentiometric and optical readout for measuring the total number of (de)protonable FGs on representatively chosen commercial and custom-made aminated silica nanoparticles (SiO2 NPs). The accuracy and robustness of our stepwise optimized workflows was assessed by several operators in two laboratories and method validation was done by cross-comparison with two analytical methods relying on different signal generation principles. This included traceable, chemo-selective quantitative nuclear magnetic resonance spectroscopy (qNMR) and thermogravimetric analysis (TGA), providing the amounts of amino silanes released by particle dissolution and the total mass of the surface coatings. A comparison of the potentiometric titration results with the reporter-specific amounts of surface amino FGs determined with the previously automated fluorescamine (Fluram) assay highlights the importance of determining both quantities for surface-functionalized NMs. In the future, combined NM surface analysis with optical assays and pH titration will simplify quality control of NM production processes and stability studies and can yield large data sets for NM grouping that facilitates further developments in regulation and standardization.
KW - Quality assurance
KW - Fluorescence
KW - Nano
KW - Particle
KW - Synthesis
KW - Characterization
KW - Advanced material
KW - Surface
KW - Standardization
KW - Reference material
KW - Functional group
KW - Quantification
KW - Coating
KW - Automation
KW - Potentiometry
KW - Method
KW - Validation
KW - Optical assay
KW - Fluram
KW - Fluorescamine
KW - qNMR
KW - Comparison
KW - ILC
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-642371
DO - https://doi.org/10.1021/acsmeasuresciau.5c00062
SN - 2694-250X
SP - 1
EP - 13
PB - American Chemical Society
CY - Washington, DC
AN - OPUS4-64237
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Stiegler, L. M. S.
A1 - Wegner, Karl David
A1 - Weigert, Florian
A1 - Peukert, W.
A1 - Resch-Genger, Ute
A1 - Walter, J.
T1 - Analysis of Giant-Shell CdSe/CdS Quantum Dots via Analytical Ultracentrifugation Combined with Spectrally Resolved Photoluminescence
N2 - Knowledge of the structure–property relationships of functional nanomaterials, including, for example, their size- and composition-dependent photoluminescence (PL) and particle-to-particle variations, is crucial for their design and reproducibility. Herein, the Angstrom-resolution capability of an analytical ultracentrifuge combined with an in-line multiwavelength emission detection system (MWE-AUC) for measuring the sedimentation coefficient-resolved spectrally corrected PL spectra of dispersed nanoparticles is demonstrated. The capabilities of this technique are shown for giant-shell CdSe/CdS quantum dots (g-QDs) with a PL quantum yield (PL QY) close to unity capped with oleic acid and oleylamine ligands. The MWE-AUC PL measurements are calibrated and validated with certified fluorescence standards. The spectrally corrected and size-dependent PL spectra of the g-QDs derived from a single MWE-AUC experiment are then analyzed and compared with the results of single-particle spectroscopic studies, yielding the PL spectra, decay kinetics, and blinking behavior of individual g-QDs. This study underlines the vast potential of MWE-AUC with in-line optical detection for the characterization of advanced nanomaterials with a complex structure.
KW - Quantum dots
KW - Analytical ultracentrifugation
KW - Photoluminescence
KW - Advanced nanomaterial characterization
KW - Calibrated fluorescence measurements
KW - Reference materials
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-624357
DO - https://doi.org/10.1002/smtd.202401700
SN - 2366-9608
SP - 1
EP - 7
PB - Wiley VHC-Verlag
AN - OPUS4-62435
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Richter, Maria
A1 - Güttler, Arne
A1 - Pauli, Jutta
A1 - Vogel, K.
A1 - Homann, Christian
A1 - Würth, Christian
A1 - Resch-Genger, Ute
T1 - Extending certified spectral fluorescence standards for the calibration and performance validation of fluorescence instruments to the NIR—closing the gap from 750 to 940 nm with two novel NIR dyes
N2 - Fluorescence techniques such as fluorescence spectroscopy, microfluorometry, and fluorescence microscopy, providing spectral, intensity, polarization, and lifetime information, are amongst the most broadly utilized analytical methods in the life and materials sciences. However, the measured fluorescence data contain sample- and instrument-specific contributions, which hamper their comparability across instruments and laboratories. Comparable, instrument-independent fluorescence data require the determination of the fluorescence instrument’s wavelength-dependent spectral responsivity, also termed emission correction curve, for the same instrument settings as those used for the fluorescence measurements as a prerequisite for the subsequent correction of the measured instrument-specific data. Such a spectral correction is essential for the performance comparison of different fluorescent labels and reporters, quantitative fluorescence measurements, the determination of the fluorescence quantum yield, and the spectroscopic measure for the fluorescence efficiency of a fluorophore. Simple-to-use tools for obtaining emission correction curves are chromophore-based reference materials (RMs), referred to as fluorescence standards, with precisely known, preferably certified instrument-independent fluorescence spectra. However, for the increasingly used near-infrared (NIR) wavelength region >700 nm, at present, no spectral fluorescence standards are available. To close this gap, we developed two novel spectral fluorescence standards, BAM F007 and BAM-F009, with broad emission bands from about 580 to 940 nm in ethanolic solution. These liquid fluorescence standards currently under certification, which will be released in 2025, will expand the wavelength range of the already available certified Calibration Kit BAM F001b-F005b from about 300–730 to 940 nm. In this research article, we will detail the criteria utilized for dye and matrix selection and the homogeneity and stability tests accompanying dye certification as well as the calculation of the wavelength-dependent uncertainty budgets of the emission spectra BAM F007 and BAM-F009, determined with the traceably calibrated BAM reference spectrofluorometer. These fluorescence standards can provide the basis for comparable fluorescence measurements in the ultraviolet, visible, and NIR for the fluorescence community.
KW - Quality assurance
KW - Reference material
KW - Fluorescence
KW - Dye
KW - Traceability
KW - Metrology
KW - Calibration
KW - Reference data
KW - Reference product
KW - Digital certificate
KW - NIR
KW - Instrument performance validation
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-626317
DO - https://doi.org/10.1007/s00216-024-05723-w
SN - 1618-2650
SP - 1
EP - 15
PB - Springer
AN - OPUS4-62631
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Resch-Genger, Ute
T1 - Molecular and nanoscale emitters photophysics , photoluminescence quantum yields, and surface chemistry
N2 - Inorganic nanocrystals such as spectrally shifting lanthanide-based nanoparticles (LnNCs) like NaYF4: Yb, Er and semiconductor quantum dots, organic and inorganic particles stained with sensor molecules, and organic dyes showing aggregation-induced emission are meanwhile broadly applied in the life and material sciences. The identification of optimum particle architectures and molecular structures for photonic applications requires quantitative spectroscopic studies and methods to control and analyse particle surface chemistry. In the following, photoluminescence studies of different emitter classes are presented, thereby addressing the measurement of particle brightness and photoluminescence quantum yields in different spectral windows parameters required for an in-depth mechanistic understanding. In addition, examples for the quantification of surface functional groups on nanomaterials with optical spectroscopy are given.
T2 - GdCH Kolloquium
CY - Düsseldorf, Germany
DA - 11.11.2025
KW - Dye
KW - Fluorescence
KW - Quantum yield
KW - Lifetime
KW - Sensor materials
KW - Temperature
KW - Cr(III) complex
KW - Nano
KW - Particle
KW - Silica
KW - Polymer
KW - Metrology
KW - Quality assurance
KW - Reference material
KW - Surface chemistry
KW - Size
KW - Shape
KW - Particle number concentration
KW - Method
KW - Optical assay
KW - qNMR
KW - Validation
KW - Potentiometry
KW - XPS
PY - 2025
AN - OPUS4-64728
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Tavernaro, Isabella
A1 - Sander, P.
A1 - Andresen, Elina
A1 - Schedler, U.
A1 - Resch-Genger, Ute
T1 - Potentiometric and Optical Titration for Cost- Efficient Quantification of Surface Functional Groups on Silica Nanoparticles
N2 - Surface chemistry of engineered nanomaterials (NMs) plays a critical role not only in determining their interactions with the environment but also in their stability, safety, and functionality across diverse applications ranging from catalysis to biomedicine. Accurate quantification of surface functional groups (FGs) is therefore essential for quality control, risk assessment, and performance optimization.[1] However, many existing analytical techniques are either cost-intensive, require specialized instrumentation, or lack scalability for routine use.
In this study, we present a comparative evaluation of potentiometric and optical titration as two simple, cost-efficient, and automatable methods for quantifying surface functional groups on a variety of surface-modified silica nanoparticles (SiO₂ NPs). These NPs were chosen as they are among the most frequently utilized engineered NMs in the life and material sciences.
Potentiometric titration, based on pH monitoring during acid-base neutralization, offers a direct and label-free approach to determine the total amount of FGs. Optical titration provides a complementary method with potential for high-throughput screening. To examine the accuracy and robustness of our stepwise-optimized workflows and the achievable relative standard deviations (RSDs), measurements were performed by multiple operators in two laboratories. Method validation was conducted through cross-comparison with traceable, chemo-selective quantitative nuclear magnetic resonance spectroscopy (qNMR) and thermogravimetric analysis (TGA). A comparison with optical assays highlights the importance of measuring both quantities for comprehensive characterization of surface-modified NMs.[2]
A combined NM surface analysis using optical assays and pH titration will simplify quality control of NM production processes and stability studies, and can yield large datasets for NM grouping in sustainable and safe(r)-by-design studies.
T2 - eMRS Fall Meeting 2025
CY - Warsaw, Poland
DA - 15.09.2025
KW - Fluorescence
KW - Advanced material
KW - Synthesis
KW - Characterization
KW - Nano
KW - Particle
KW - Silica
KW - Surface analysis
KW - Validation
KW - qNMR
KW - Fluram assay
KW - Functional group
KW - Quantification
KW - Potentiometry
KW - Amino groups
KW - Fluorescamine
KW - Calibration
KW - Method comparison
PY - 2025
AN - OPUS4-64205
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Resch-Genger, Ute
T1 - Quantifying functional groups and coatings on nanoobjects
N2 - Engineered nanomaterials (NM) of different size, shape, chemical composition, and surface chemistry are increasingly used for many key technologies of the 21st century and consumer products. This includes polymer and silica or silica-coated nanoparticles (NP) with covalently bound surface groups, semiconductor quantum dots (QD), metal and metal oxide NP, and lanthanide NP with coordinatively or electrostatically bound ligands, as well as surface-coated nanostructures like micellar encapsulated NP. Decisive for most applications of NMs are their specific surface properties, which are largely determined by the chemical nature and amounts of ligands and functional groups (FGs) on the NM surface. The surface chemistry can strongly affect the physicochemical properties of NM, their charge, hydrophilicity/hydrophobicity, reactivity, function, stability, and processability and thereby their impact on human health and environment. Knowledge of NM surface chemistry plays an important role for NM functionality and performance in (bio)applications and the fate, exposure, dissolution, transformation, and accumulation of NM, and thus, the potential risks for human health and the environment. This highlights the importance of reliable, validated, and eventually standardized analytical methods for analyzing and quantifying NM surface chemistry for process and quality control of NM production, safe use of NMs, design of novel NM, and sustainable concepts for NM fabrication.[1-3] In this context, interlaboratory comparisons (ILCs) are needed to assess method reliability and reference materials with known surface chemistries for establishing surface analytical methods and their performance validation.[2,4] Also, to respond to the increasing number of samples to be analyzed, cost-efficient automation concepts for surface analysis are needed that can be realized with affordable and preferably commercial instrumentation.[5] Here, we provide an overview of analytical methods for FG analysis and quantification used by us for quantifying broadly utilized FGs and ligands on different types of NMs with electrochemical titration methods, optical assays, nuclear magnetic resonance (NMR) and vibrational (IR) spectroscopy, and X-ray based and thermal analysis methods.[1,2] Thereby, method- and material-related challenges are addressed, and the importance of multi-method characterization approaches easing method validation by method cross-validation. Special emphasis is dedicated to simple, versatile, and cost-efficient methods such as optical assays and electrochemical titration methods.
T2 - eMRS Fall Meeting 2025
CY - Warsaw, Poland
DA - 15.09.2025
KW - Quality assurance
KW - Fluorescence
KW - Nano
KW - Particle
KW - Synthesis
KW - Characterization
KW - Advanced material
KW - Surface
KW - Standardization
KW - Reference material
KW - Functional group
KW - Quantification
KW - Coating
KW - Interlaboratory comparison
KW - Uncertainty
PY - 2025
AN - OPUS4-64183
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Resch-Genger, Ute
T1 - Assessing different types of silica networks for the complete protection of nir luminescent molecular rubies from oxygen quenching in air
N2 - The application of emerging luminophores such as near-infrared (NIR) emissive earth-abundant chromium(III) (CrIII) complexes and triplet-triplet annihilation upconversion (TTA-UC) systems in air as optical reporters for bioimaging or photonic materials for energy conversion requires simple and efficient strategies for their complete protection from luminescence quenching by oxygen. Therefore, we explored the influence of sol-gel synthesis routes on the oxygen protection efficiency of the resulting core and core/shell silica nanoparticles (SiO2 NPs), utilizing the molecular ruby-type luminophores CrPF6 ([Cr(ddpd)2](PF6)3; ddpd = N,N’-dimethyl- N,N’-dipyridin-2-ylpyridin-2,6-diamine) and CrBF4 ([Cr(ddpd)2](BF4)3) with their oxygen-dependent, but polarity-, proticity-, viscosity-, and concentration-independent luminescence as optical probes for oxygen permeability. The sol-gel chemistry routes we assessed include the classical Stöber method and the underexplored larginine approach, which relies on the controlled hydrolysis of tetraethoxysilane (TEOS) in a biphasic cyclohexane/water system with the catalyst l-arginine. As demonstrated by luminescence measurements of air- and argon-saturated dispersions of CrPF6- and CrBF4-stained SiO2 NPs of different size and particle architecture, utilizing the luminescence decay kinetics of argon-saturated solutions of CrPF6 and CrBF4 in acetonitrile (ACN) as benchmarks, only SiO2 NPs or shells synthesized by the l-arginine approach provided complete oxygen protection of the CrIII complexes under ambient conditions. We ascribe the different oxygen shielding efficiencies of the silica networks explored to differences in density and surface chemistry of the resulting nanomaterials and coatings, leading to different oxygen permeabilities. Our l-arginine based silica encapsulation strategy can open the door for the efficient usage of oxygen-sensitive luminophores and TTA-UC systems as optical reporters and spectral shifters in air in the future.
T2 - eMRS Strasbourg
CY - Strasbourg, France
DA - 26.05.2025
KW - Quality assurance
KW - Fluorescence
KW - Nano
KW - Particle
KW - Synthesis
KW - Quantum yield
KW - NIR
KW - Mechanism
KW - Characterization
KW - Electron microscopy
KW - Silica
KW - Oxygen sensing
KW - Surface
KW - Doping
KW - Lifetime
KW - Cr(III) complex
PY - 2025
AN - OPUS4-63300
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Frenzel, F.
A1 - Fiedler, S.
A1 - Bardan, A.
A1 - Güttler, Arne
A1 - Würth, Christian
A1 - Resch-Genger, Ute
T1 - Influence of Measurement Geometry and Blank on Absolute Measurements of Photoluminescence Quantum Yields of Scattering Luminescent Films
N2 - For a series of 500 μm-thick polyurethane films containing different concentrations of luminescent and scattering YAG:Ce microparticles, we systematically explored and quantified pitfalls of absolute measurements of photoluminescence quantum yields (Φf) for often employed integrating sphere (IS) geometries, where the sample is placed either on a sample holder at the bottom of the IS surface or mounted in the IS center. Thereby, the influence of detection and illumination geometry and sample position was examined using blanks with various scattering properties for measuring the number of photons absorbed by the sample. Our results reveal that (i) setup configurations where the scattering sample is mounted in the IS center and (ii) transparent blanks can introduce systematic errors in absolute Φf measurements.
For strongly scattering, luminescent samples, this can result in either an under- or overestimation of the absorbed photon flux and hence an under- or overestimation of Φf. The size of these uncertainties depends on the scattering properties of the sample and instrument parameters, such as sample position, IS size, wavelength-dependent reflectivity of the IS surface coating, and port configuration. For accurate and reliable absolute Φf measurements, we recommend (i) a blank with scattering properties closely matching those of the sample to realize similar distributions of the diffusely scattered excitation photons within the IS, and (ii) a sufficiently high sample absorption at the excitation wavelength. For IS setups with center-mounted samples, measurement geometries should be utilized that prevent the loss of excitation photons by reflections from the sample out of the IS.
KW - Quality assurance
KW - Fluorescence
KW - Nano
KW - Particle
KW - Quantum yield
KW - Characterization
KW - Silica
KW - Scattering
KW - Uncertainty
KW - Film
KW - Pphosphor
KW - YAG:Ce
KW - LED
KW - Converter material
KW - Solid material
KW - Polymer
KW - Composite material
KW - Advanced material
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-638304
DO - https://doi.org/10.1021/acs.analchem.4c06726
SN - 1520-6882
SP - 1
EP - 8
PB - ACS Publications
AN - OPUS4-63830
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Güttler, Arne
T1 - Certified Reference Materials for the Quantification and Standardization of Fluorescence-based Measurements
N2 - The size and shape of photoluminescence signals is affected by wavelength-, polarization-, and time-dependent instrumentspecific contributions and the compound- and environment-specific photoluminescence quantum yield. The former hamper the comparability of fluorescence measurements performed on different measuring devices. The commonly relatively done determination of the performance parameter requires suitable quantum yield standards with well-known. The performance of such measurements is, e.g., described in the written standard IEC 62607 currently revised.
T2 - Colloquium für Optische Spektrometrie 2025
CY - Jena, Germany
DA - 24.09.2025
KW - Quality assurance
KW - Fluorescence
KW - Nano
KW - Particle
KW - Advanced material
KW - Calibration
KW - Characterization
KW - Fluorescence quantum yield
KW - Phosphor
KW - Absolute
KW - Integrating sphere spectroscopy
KW - Dye
KW - Standardization
KW - Reference material
KW - Interlaboratory comparison
KW - Uncertainty
PY - 2025
AN - OPUS4-64213
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Oskoei, Parastu
T1 - Thermoresponsive UCNP@MSN Nanoparticles for Doxorubicin Delivery in Melanoma Cells
N2 - Upconversion nanoparticles (UCNPs) possess unique photophysical characteristics, such as excita bility by near infrared (NIR) light, which facilitates deep tissue penetration, multi color emission , long luminescence lifetimes, and an excellent photostability. These features have made UCNPs promising tools for biomedical applications . M esoporous silica nanoparticles (MSNs) functionalized with stimuli responsive nanovalves or specific coatings enable the encapsulation and controlled release of therapeutic agen ts, thereby offering spatiotemporal precision in drug delivery 1 3 ]]. Among drug delivery strategies, photoresponsive systems have attracted growing attention due to their potential for clinical applications . This is especially relevant for melanoma, an aggressive skin cancer with increasing global incidence, for which conventional therapeutic modalities remain largely insufficient in advanced stage 4 In this work, core shell UCNP@MSN nanoparticles were synthetised by coating UCNPs with a mesoporous silica layer, which was subsequently functionalized with thermoresponsive retro Diels Alder nanovalves [ and loaded with the chemotherapeutic agent doxorubicin (DOX). Controlled drug release was effectively achieved under 980 nm NIR i llumination . Treatment with functionalized nanoparticles significantly reduced the viability of melanoma cell lines, with an enhanced cytotoxicity being observed upon combined nanoparticle exposure and NIR illumination . Mechanistic analyses revealed that neither UCNPs nor NIR i llumination alone could induce the production of reactive oxygen species (ROS); however, their combination induced a marked increase in ROS levels in two of the three tested cell lines. Furthermore, this dual treatment promoted substantial apoptotic and/or necrotic responses across all cell models. These findings underscore the potential of UCNP@MSN nanoplatforms, equipped with thermoresponsive ga tes , as efficient photoactivated drug delivery systems for melanoma therapy.
T2 - Conference Jornadas CICECO
CY - Aveiro, Portugal
DA - 09.10.2025
KW - Nano
KW - Particle
KW - Lanthanide
KW - Upconversion
KW - Surface chemistry
KW - Mesoporous silica
KW - Doxorubicin
KW - Nanomedicine
KW - Triggered release
KW - pH
KW - Cellular uptake
KW - Toxicity
KW - Folate
KW - Ligand
PY - 2025
AN - OPUS4-64371
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Resch-Genger, Ute
T1 - Quantifying the total and accessible amount of surface functionalities and ligands on nanomaterials
N2 - Engineered nanomaterials (NMs) of various chemical composition and surface functionalization are routinely fabricated for industrial applications such as medical diagnostics, drug delivery, sensing, catalysis, energy conversion and storage, opto-electronics, and information storage. NM dispersibility, stability, processability, and function as well as the interaction with biological species and environmental fate are largely determined by NM surface functionalities, i.e., functional groups (FGs) and ligands. Therefore, reliable, reproducible, and eventually standardized surface characterization methods are vital for quality control of NMs, and mandatory to meet increasing concerns regarding their safety.
Suitable methods for determining surface functionalities on ligand-stabilized core and core/shell NPs include advanced techniques such as traceable quantitative nuclear magnetic resonance (qNMR) as well as X-ray electron spectroscopy (XPS) and time of flight secondary ion mass spectrometry (ToF-SIMS), and simpler optical and electrochemical methods.[1] The latter less costly and fast methods, which can be automated, are often used by NM producers for process and quality control.[1,2] To validate methods, establish measurement uncertain-ties, test reference materials, and produce reference data, multi-method characterization studies are needed.[3,4] as well as interlaboratory comparisons (ILC) on determining NM surface chemistry and well characterized test and reference NMs providing benchmark values.[5,6] Here, we present examples for quantifying common surface FGs such as amino and carboxyl groups on functional NMs of different chemical composition such as silica, polymer, iron oxide, and lanthanide-based upconversion nanoparticles with optical assays, electrochemical titration methods, qNMR, and chromatographic separation techniques. In addition, ongoing interlaboratory comparisons will be presented.
T2 - Yucomat 2025
CY - Herec Novi, Montenegro
DA - 01.09.2025
KW - Quality assurance
KW - Fluorescence
KW - Nano
KW - Particle
KW - Synthesis
KW - Characterization
KW - Advanced material
KW - Surface
KW - Standardization
KW - Reference material
KW - Functional group
KW - Quantification
KW - Coating
KW - Interlaboratory comparison
KW - Uncertainty
PY - 2025
AN - OPUS4-64182
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Resch-Genger, Ute
T1 - Measurements of Photoluminescence Quantum Yields of Scattering LED Converter Materials
N2 - How to Get it Right with the Absolute Measurement of Photoluminescence Quantum Yields of Scattering LED Converter Materials Saskia Fiedler+,a, Florian Frenzel+,a, Christian Würth a, Isabella Tavernaro a, Michelle Grüne c, Stefan Schweizer c,d, Axel Engel e, and Ute Resch-Genger a* a Division Biophotonics, Federal Institute for Materials Research and Testing (BAM), Richard-Willstaetter-Strasse 11, D-12489 Berlin, Germany; email: ute.resch@bam.de b Present address: Photonic Materials, NWO-Institute AMOLF, Science Park 104, 1098 XG Amsterdam, The Netherlands c Faculty of Electrical Engineering, South Westphalia University of Applied Sciences, Lübecker Ring 2, 59494, Soest, Germany d Fraunhofer Application Center for Inorganic Phosphors, Branch Lab of Fraunhofer Institute for Microstructure of Materials and Systems IMWS, Lübecker Ring 2, 59494, Soest, Germany e Schott AG Technical Services, Hattenbergstrasse 10, D-55122 Mainz, Germany Optical measurements of scattering materials such as luminescent nano- and microparticles and phosphors dispersed in liquid and solid matrices play an important role in energy conversion, solid-state lighting, medical diagnostics, and security barcoding. A key performance parameter is the photoluminescence quantum yield QY, i.e., the number of emitted per number of absorbed photons. QY of transparent luminophore solutions can be obtained relative to a fluorescence QY standard of known QY, meanwhile available as certified reference materials.[1] The determination of QY of scattering liquid and solid samples like nanoparticle dispersions, phosphors, and optoceramics requires, however, absolute measurements with an integrating sphere setup. Despite the need for reliable absolute QY measurements, no interlaboratory comparison (ILCs) on measurement uncertainties has been performed and scattering standards with known QY are not available. We present the results of an ILC of 3 labs from academia and industry on measurements of transparent and scattering dye solutions and solid phosphors and converter materials like YAG:Ce optoceramics with commercial stand-alone integrating sphere setups of different illumination and detection geometries. Special emphasis was dedicated to the influence of measurement geometry, optical properties of the blank for determining the number of incident photons absorbed by the sample, and sample-specific surface roughness. Matching QY values could be obtained for transparent dye solutions and scattering dispersions with a blank with scattering properties closely matching those of the sample, QY measurements of optoceramic samples with different blanks revealed substantial differences of more than 20 %. Based on our data, we recommend non-absorbing blank materials with a high reflectivity (>95 %) such as a 2 mm-thick PTFE target placed on the sample holder as blanks.
T2 - eMRS
CY - Strasbourg, France
DA - 26.05.2025
KW - Quality assurance
KW - Fluorescence
KW - Nano
KW - Particle
KW - Quantum yield
KW - NIR
KW - Characterization
KW - Electron microscopy
KW - Film
KW - Integrating sphere spectroscopy
KW - Calibration
KW - Lifetime
KW - Advanced materials
KW - LED converter
KW - YAG:Ce
KW - ILC
KW - Measurement uncertainty
KW - Absolute quantum yield
PY - 2025
AN - OPUS4-63327
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Rezvani, A.
A1 - Wang, Z.
A1 - Wegner, Karl David
A1 - Soltanmoradi, H.
A1 - Kichigin, A.
A1 - Zhou, X.
A1 - Gantenberg, T.
A1 - Schram, J.
A1 - Zubiri, B. A.
A1 - Spiecker, E.
A1 - Walter, J.
A1 - Resch-Genger, Ute
A1 - Segets, D.
T1 - Separation of Indium Phosphide/Zinc Sulfide Core−Shell Quantum Dots from Shelling Byproducts through Multistep Agglomeration
N2 - Semiconductor quantum dots (QDs) possess unique electronic and optical properties, making them promising candidates for applications in lightemitting diodes, solar cells, bioimaging, and photocatalysis. Precise control over their size, shape, and chemical and electronic structure is crucial to ensure the desired functional properties and optimize device performance. However, challenges in QD synthesis and post-synthesis modification persist, especially in large-scale production. This study addresses the classification of QDs synthesized in a tubular flow reactor consisting of a mixture of the desired InP/ZnS core−shell QDs and QDs made from the shell material, i.e., here ZnS QDs formed as a byproduct during the formation step of the ZnS shell. The homogeneous nucleation of ZnS nanoparticles from the shelling material introduces a heterogeneity in size and composition and affects the optical properties of the resulting QDs. To address this issue, we developed a size-selective agglomeration (SSA) technique by incrementally introducing ethanol as a poor solvent and classified the synthesized QDs into 13 distinct fractions. These 13 fractions are sorted into three distinct groups: (i) larger InP/ZnS QDs, (ii) a combination of smaller InP/ZnS QDs and larger ZnS QDs, and (iii) predominant ZnS QDs with some very tiny InP/ZnS QDs. The comprehensive characterization of the fractions was conducted using UV−visible absorption spectroscopy, photoluminescence spectroscopy, high-resolution scanning transmission electron microscopy, energy-dispersive X-ray spectroscopy, total reflection X-ray fluorescence, and analytical ultracentrifugation. We could demonstrate that our method effectively separated unwanted ZnS QDs from the target InP/ZnS QDs. In addition, the fractions enriched in smaller InP/ZnS QDs exhibited a higher photoluminescence quantum yield compared to the fractions with larger QDs. This demonstrates the efficacy of SSA in finetuning the composition of QD mixtures produced on a larger scale to improve their functional properties. This approach provides fundamental understanding toward the development of a scalable two-dimensional classification process for such ultrasmall nanoparticles by particle size and composition.
KW - Quality assurance
KW - Reference material
KW - Nano
KW - Particle
KW - Quantum dot
KW - Synthesis
KW - Flow reactor
KW - InP
KW - Shell
KW - ZnS
KW - Surface chemistry
KW - Method
KW - Fluorescence
KW - Quantum yield
KW - TEM
PY - 2025
DO - https://doi.org/10.1021/acsnano.4c18530
SN - 1936-086X
VL - 19
IS - 20
SP - 19080
EP - 19094
PB - ACS Publications
AN - OPUS4-63215
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Oskoei, Párástu
T1 - Cell mechanisms induced by doxorubicin-loaded UCNP@MSN nanoparticles with a thermosresponsive nanovalve in melanoma cells
N2 - Upconversion nanoparticles (UCNPs) exhibit several remarkable optical properties, including excitation by near infrared (NIR) light, which enables deep tissue penetration, multiple distinct emission bands across a wide range of wavelengths, long luminescen ce lifetimes, and high photostability. These features make them particularly attractive for various biomedical applications. Mesoporous silica nanoparticles (MSNs), functionalized with nanovalves or specific coatings, have been explored for controlled and targeted drug delivery, where therapeutic agents are encapsulated within the nanopores, allowing spatiotemporal release 1 3 ]]. Among the promising approaches, photoactivated drug delivery systems have drawn considerable interest due to their versatility and potential. One relevant application is in the treatment of melanoma, an aggressive form of skin cancer with a rising global incidence. In advanced stages, conventional therapies often fail to achieve complete tumour eradication, resulting in poor prognose s 4 In this study, UCNPs were coated with a mesoporous silica shell to form core shell UCNP@MSN nanoparticles, which were further functionalized with thermoresponsive retro Diels Alder nanovalves and loaded with doxorubicin (DOX), a chemotherapeutic drug used in melanoma treatment. Upon exposure to 980 nm NIR light, DOX release was successfully triggered in the culture medium. Exposure to functionalized UCNPs decreased the viability of the tested melanoma cell lines, with further reductions observed when the ex posure to the nanoparticles was combined with irradiation. Subsequently, t he toxicity mechanisms were evaluated and showed that w hile individual treatments with either the functionalized UCNPs or NIR irradiation alone had no effect on reactive oxygen species (ROS) production, their combination significantly increased ROS levels in two of the three tested cell lines. This combined treatment also led to notable increases in apoptotic , necrotic or both type of cells’ percentages on all cell lines. Overall, these findings highlight the potential of these nanoparticles with thermoresponsive gating mechanisms as effective platforms for targeted drug delivery in melanoma therapy.
T2 - EUROTOX 2025
CY - Athens, Greece
DA - 14.09.2025
KW - Nano
KW - Particle
KW - Lanthanide
KW - Upconversion
KW - Surface chemistry
KW - Mesoporous silica
KW - Doxorubicin
KW - Nanomedicine
KW - Triggered release
KW - pH
KW - Cellular uptake
KW - Toxicity
KW - Folate
KW - Ligand
PY - 2025
AN - OPUS4-64372
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Tavernaro, Isabella
A1 - Simon, Fabian
A1 - Gehrenkemper, Lennart
A1 - Tobias, Charlie
A1 - Resch-Genger, Ute
A1 - Meermann, Björn
T1 - Quantification of the amount of surface groups of aminated silica nano- and microparticles utilizing a fluorine tag and HR-CS-GFMAS
N2 - The performance, bioavailability, and safe use of engineered nanomaterials (NMs) depends not only on properties such as size, shape, and surface area, but largely on surface chemistry. While many sizing methods have been established, there is still a lack of validated screening methods for determining NM surface functional groups (FGs). In this context, we present a fast and simple method for FG quantification using high resolution-continuum source-graphite furnace molecular absorption spectrometry (HR-CS-GFMAS) and assess its applicability for the surface analysis of representatively chosen aminated silica nanoparticles (NPs) and microparticles (MPs) in conjunction with amino FG labeling with a fluorine tag. For this proof-of-concept study, first surface amino FG screening of the silica NPs and MPs was done with a potentiometric back titration method, providing the total amount of protonatable surface FGs, and two optical assays relying on reporter dyes with sizes and spatial requirements, i.e., surface binding areas smaller or larger than that of the fluorine tag to estimate the maximum and reporter-accessible number of amino FGs. Subsequently, the surface amino FGs were labeled with the fluorine tag 4-(trifluoromethyl)benzoic acid (TFMB) and the amount of fluorine originating from the bound TFMB molecules was quantified by HR-CS-GFMAS in two common organic solvents, i.e., dimethyl sulfoxide (DMSO) or ethanol (EtOH) to assess possible interferences from organic matrices. Our study revealed limits of detection (LODs) and quantification (LOQs) for fluorine of 1.0 µg/L and 3.5 µg/L in EtOH and 1.5 µg/L and 5.0 µg/L in DMSO, respectively. Overall, a quick and simple method for analyzing surface FGs on NPs and MPs was presented utilizing broadly available fluorine tags and HR-CS-GFMAS for fluorine quantification, which can be applied, e.g., for homogeneity, stability, and aging studies of surface-modified particles. This could contribute to ease the understanding of property-safety relationships for surface-functionalized NMs.
KW - Fluorine Analysis
KW - Nano- and microparticles
KW - Surface group quantification
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-641965
DO - https://doi.org/10.1007/s00216-025-06107-4
SN - 1618-2642
SP - 1
EP - 11
PB - Springer Science and Business Media LLC
CY - Berlin ; Heidelberg
AN - OPUS4-64196
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Oskoei, Párástu
T1 - Effects of upconversion nanoparticles with a thermo-responsive nanovalve loaded with doxorubicin in melanoma cells
N2 - Melanoma skin cancer has an increasingly higher incidence , and w hen detected in advanced stages, tumour eradication is often incomplete, contributing to poor prognosis with conventional treatments. Upconversion nanoparticles (UCNPs) have unique properties, such as excitability under near infrared (NIR) excitation light, which confers a relatively high penetration depth in tissue that allow their effective use in several biomedical applications Mesoporous silica nanoparticles (MSN) with nanovalves or derived coatings have widely been used for triggered and targeted drug delivery in the past. Anticancer drugs can be loaded into the pores of MSN, enabling controlled drug release. In this work, UCNPs were coated with a mesoporous silica shell yielding UCNP@MSN core shell nanoparticles which were equipped with thermoresponsive retro Diels Alder nanovalves and then loaded with DOX , a chemotherapeutic agent for melanoma treatmen t (UCNP@MSN DOX) Subsequent DOX release from this drug delivery system was triggered by 980 nm NIR light. Melanoma cells exposed to UCNP@MSN DOX or the NIR laser exhibited no change in ROS production , while the combination of both induced an increase in ROS production. This combination of conditions also induced changes on apoptosis and necrosis levels. These findings underscore the potential use of UCNP @MSN drug delivery systems with thermoresponsive caps as effective drug delivery platforms for melanoma therapy.
T2 - VII iBiMED Symposium
CY - Aveiro, Portugal
DA - 23.05.2025
KW - Nano
KW - Particle
KW - Lanthanide
KW - Upconversion
KW - Surface chemistry
KW - Mesoporous silica
KW - Doxorubicin
KW - Nanomedicine
KW - Triggered release
KW - pH
KW - Cellular uptake
KW - Toxicity
KW - Folate
KW - Ligand
PY - 2025
AN - OPUS4-64373
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - GEN
A1 - Resch-Genger, Ute
A1 - Richter, Maria
A1 - Güttler, Arne
A1 - Pauli, Jutta
A1 - Vogel, K.
A1 - Homann, Christian
A1 - Würth, Christian
T1 - Extending Certified Spectral Fluorescence Standards for the Calibration and Performance Validation of Fluorescence Instruments to the NIR – Closing the Gap from 750 nm to 940 nm with Two Novel NIR Dyes
N2 - Fluorescence methods provide spectral, intensity, polarization, and lifetime information, which contain sample- and instrument-specific contributions. Fluorescence data, comparable across instruments and laboratories, require validated calibration procedures and certified fluorescence standards.
KW - Quality assurance
KW - Reference material
KW - Fluorescence
KW - Dye
KW - Traceability
KW - Metrology
KW - Calibration
KW - Reference data
KW - Reference product
KW - Digital certificate
KW - NIR
KW - Instrument performance validation
PY - 2025
SP - 1
EP - 4
PB - Springer Nature
CY - London
AN - OPUS4-62739
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Andreato, E.
A1 - Panov, N.
A1 - Artiga, A.
A1 - Osipova, Viktoriia
A1 - Resch-Genger, Ute
A1 - Ximendes, E.
A1 - Molina, P.
A1 - Canton, P.
A1 - Marin, R.
T1 - Indium-Based Fluoride Nanoparticles Doped with Chromium for Near-Infrared Luminescence
N2 - Transition metal (TM) and rare earth (RE) ion-doped nanoparticles (NPs) are photoluminescent materials of technological relevance in bioimaging, sensing, and light conversion. Fluoride NPs are particularly attractive in this context, since they combine low-energy phonons, high chemical stability, optical transparency, size, and architecture tunability. Yet, nearly all reported colloidal fluoride NPs (e.g., NaYF4 and LiYF4) can only be efficiently doped with RE3+ and not with luminescent TM ions. Herein, we contribute to filling this gap in materials science by reporting Na3InF6 NPs doped with Cr3+ as a model luminescent TM ion. We unveil the heat-driven NP formation mechanism, which involves a cubic-to-monoclinic phase conversion, similarly to the cubic-tohexagonal phase conversion in NaYF4. Reaction temperatures above 225 °C and reaction time have a limited impact on the NP morphology, while the amount of fluoride precursor and oleylamine grants control over the NP size. After verifying that Na3InF6 NPs show negligible cytotoxicity toward U-87 cell line, we study the optical properties of these NPs upon Cr3+ doping.
Temperature-dependent photoluminescence measurements indicate that Cr3+ ions experience a weak crystal field in the Na3InF6 host lattice, while their photoluminescence lifetime varies linearly in the 20−50 °C range. These results set the ground for further studies of photoluminescent TM-doped fluoride NPs, toward their applications in bioimaging, sensing, and light-converting devices.
KW - Quality assurance
KW - Fluorescence
KW - Traceability
KW - Nano
KW - Particle
KW - Synthesis
KW - Quantum yield
KW - NIR
KW - Mechanism
KW - Characterization
KW - XRD
KW - Phase transition
KW - Ligand
KW - Surface
KW - Doping
KW - Lifetime
PY - 2025
DO - https://doi.org/10.1021/acs.chemmater.4c03335
SN - 1520-5002
SP - 1
EP - 14
PB - American Chemical Society
AN - OPUS4-63073
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Matiushkina, Anna
T1 - Quantification of Citrate Ligands on Nanoparticle Surfaces
N2 - To ensure the successful advancement of nanomaterials (NM) in applications and their safe use, it is crucial to develop reliable methods to control and quantify ligands and functional groups (FG) on the nanoparticle (NP) surface as surface chemistry largely determines the interactions of NPs with their surroundings. Many analytical methods can be used for this purpose. However, their applicability strongly depends on the type of NM and ligand(s) and most of them require challenging protocols for sample preparation, i.e., the removal of the NPs or their dissolution, which can influence the accuracy of the measurements. While some methods allow the precise quantification of specific ligands such as quantitative nuclear magnetic resonance (qNMR), others provide only semi-quantitative results like Fourier Transform infrared spectroscopy (FTIR) or target more general analyte groups like thermogravimetric analysis (TGA) detecting mass losses (total organic content) or conductometry (e.g., (de)protonable FGs such as carboxyl or amine groups). [1] The calculation of the coverage of the NP surface with ligands, additionally requires knowledge of their total surface area, which can be obtained, e.g., from a precise characterization of NP size and concentration.
Citrate is one of the most frequently utilized surface ligand for stabilizing metal, metal oxide, and lanthanide-based upconversion NPs in hydrophilic environments. However, its quantification on NP surfaces has rarely been addressed although it is a frequent analyte in medical or food analysis. In this study we compare several methods for quantifying citrate as capping ligands of iron oxide NPs (IONPs), exemplarily chosen because of their broad applications in the life science. [2] The size of the IONPs was characterized by electron microscopy (EM) and dynamic light scattering (DLS), while their concentration was determined by quantifying iron ions after acidic particle dissolution using a colorimetric assay and inductively coupled plasma optical emission spectroscopy (ICP-OES). The simplest approach for citrate quantification, direct photometric UV-detection after acidic digestion of the IONPs, yielded only reasonable results when combined with reversed phase high-performance liquid chromatography (HPLC). These results were cross validated with qNMR that required the development of a reliable sample preparation protocol addressing not only particle dissolution in deuterated solvents but also the removal of the paramagnetic iron ions interfering with NMR measurements. Comparison with results from TGA gives insight into the sensitivity and specificity of these methods and their potential for quantifying surface ligands on NPs.
T2 - Anakon 2025
CY - Leipzig, Germany
DA - 10.03.2025
KW - Advanced material
KW - Functional group
KW - Iron oxide
KW - Ligand
KW - Nano
KW - Particle
KW - Quantification
KW - Surface analysis
PY - 2025
AN - OPUS4-64861
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Gawlitza, Kornelia
T1 - Using Dual Fluorescent Molecularly Imprinted Particles Coupled with a Miniaturized Opto-Microfluidic Platform for On-Site Detection of Perfluoroalkyl Carboxylic Acids
N2 - Per- and polyfluoroalkyl substances (PFAS) are a group of synthetic organofluorine chemicals widely used in the production of various materials, including firefighting foams, adhesives, and coatings that resist stains and oil. In recent years, PFAS have gained attention as emerging environmental contaminants, with particular emphasis on perfluoroalkyl carboxylic acids (PFCAs), the most common type of PFAS. PFCAs are defined by a fully fluorinated carbon chain and a charged carboxylic acid group. They have been classified as Substances of Very High Concern and included in the REACH Candidate List due to their persistence, resistance to biodegradation, and toxicological impacts.
Traditional methods for analyzing PFCAs, like GC-MS, HRMS, and HPLC-based techniques, are time-consuming, non-portable, expensive, and require specialized expertise. On the other hand, fluorescence assays offer a user-friendly, portable, and cost-effective alternative with high sensitivity and quick results, particularly when the binding of the analyte causes a specific increase in the probe’s fluorescence. Combining these probes with a carrier platform and a miniaturized optofluidic device presents a promising approach for PFCA monitoring.
In this study, a new guanidine BODIPY fluorescent indicator monomer was synthesized, characterized, and incorporated into a molecularly imprinted polymer (MIP) designed for the specific detection of perfluorooctanoic acid (PFOA). The MIP layer was formed on silica core nanoparticles doped with tris(bipyridine)ruthenium(II) chloride, serving as an optical internal reference for calibration-free assays. In combination with an extraction step prior to sample analysis, this system enables selective and reliable detection of PFCAs in surface water samples, minimizing interference from competing substances, matrix effects, and other factors. When integrated into an opto-microfluidic setup, the assay provided a compact, user-friendly detection system capable of detecting micromolar levels of PFOA in under 15 minutes from surface water samples.
T2 - ANAKON2025
CY - Leipzig, Germany
DA - 10.03.2025
KW - Perfluorooctanoic Acid (PFOA)
KW - On-site detection
KW - Fluorescence
KW - Microfluidics
KW - Molecularly Imprinted Polymers
PY - 2025
AN - OPUS4-62712
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Fayis Kalady, Mohammed
A1 - Schultz, Johannes
A1 - Weinel, Kristina
A1 - Wolf, Daniel
A1 - Lubk, Axel
T1 - Geometry-dependent localization of surface plasmons on random gold nanoparticle assemblies
N2 - Assemblies of plasmonic nanoparticles (NPs) support hybridized modes of localized surface plasmons (LSPs), which delocalize in geometrically well-ordered arrangements. Here, the hybridization behavior of LSPs in geometrically completely disordered two-dimensional arrangements of Au NPs fabricated by an e-beam synthesis method is studied. Employing electron energy loss spectroscopy in a scanning transmission electron microscope and numerical simulations, the disorder-driven spatial and spectral localization of the coupled LSP modes that depends on the NP thickness is revealed. Below a NP thickness of 0.4 nm, localization increases toward higher hybridized LSP mode energies. In comparison, above 10 nm thickness, a decrease of localization toward higher mode energies is observed. In the intermediate thickness regime, a transition of the energy dependence of the localization between the two limiting cases, exhibiting a mode energy with minimal localization, is observed. It is shown that this behavior is mainly driven by the energy and thickness dependence of the polarizability of the individual NPs.
KW - Gold Nanoparticles
KW - Surface plasmons
KW - Electron enerdy loss spectroscopy (EELS)
KW - scanning transmission electron microscopy
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-647230
DO - https://doi.org/10.1103/44nk-6bp2
SN - 2643-1564
VL - 7
IS - 043053
EP - 4
PB - American Physical Society
AN - OPUS4-64723
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Homann, Christian
A1 - Peeters, Régis
A1 - Mirmajidi, Hana
A1 - Berg, Jessica
A1 - Fay, Michael
A1 - Rodrigues, Lucas Carvalho Veloso
A1 - Radicchi, Eros
A1 - Jain, Akhil
A1 - Speghini, Adolfo
A1 - Hemmer, Eva
T1 - Rapid microwave-assisted synthesis of morphology-controlled luminescent lanthanide-doped Gd2O2S nanostructures
N2 - Gadolinium oxysulfide (Gd2O2S) is an attractive material of demonstrated suitability for a variety of imaging applications, leveraging its magnetic, scintillating, and luminescent properties, particularly when doped with optically active lanthanide ions (Ln3+). For many of these applications, control over size and morphology at the nanoscale is crucial. This study demonstrates the rapid microwave-assisted Synthesis of colloidal Ln2O2S (Ln = Gd and dopants Yb, Er, Tb) nanostructures in as little as 20 min. Structural characterization using X-ray diffraction analysis (XRD), Raman spectroscopy, as well as Transmission electron microscopy (TEM), including elemental mapping via energy dispersive X-ray spectroscopy (EDS), unveiled the key role of elemental sulphur (S8) in the reaction mixtures for materials growth. By systematically varying the Ln-to-S ratio from 1 : 0.5 to 1 : 15, controlled morphologies ranging from triangular nanoplatelets to berry- and flower-like shapes were achieved. Doping with Er3+/Yb3+ endowed the nano-triangles with upconverting and near-infrared emitting properties. Tb3+-doped Gd2O2S exhibited the characteristic green Tb3+ emission under UV excitation, while also showing X-ray excited optical luminescence (XEOL), rendering the material interesting as a potential nano-scintillator.
KW - Upconversion
KW - Microwave-assisted synthesis
KW - Synthesis
KW - Fluorescence
KW - Nano
KW - Particle
KW - NIR
KW - XRD
KW - X-ray fluoressence
KW - Morphology control
KW - Raman
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-647907
DO - https://doi.org/10.1039/D5TC01646K
SN - 2050-7526
VL - 13
IS - 35
SP - 18492
EP - 18507
PB - Royal Society of Chemistry (RSC)
AN - OPUS4-64790
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Adamski, Paweł
A1 - Zgrzebnicki, Michał
A1 - Albrecht, Aleksander
A1 - Jurkowski, Artur
A1 - Wojciechowska, Agnieszka
A1 - Ekiert, Ewa
A1 - Sielicki, Krzysztof
A1 - Mijowska, Ewa
A1 - Smales, Glen J.
A1 - Maximenko, Alexey
A1 - Moszyński, Dariusz
T1 - Ammonia synthesis over γ-Al2O3 supported Co-Mo catalysts
N2 - Novel ammonia synthesis catalysts are sought due to energetic transformation and increasing environmental consciousness. Materials containing cobalt and molybdenum are showing state-of-art activities in ammonia synthesis. The application of γ-alumina support was proposed to enhance the properties of Co-Mo nanoparticles. The wet impregnation of the support was conducted under reduced pressure. The active catalysts were obtained by ammonolysis of precursors. The chemical and phase composition, as well as morphology, porosity, and surface composition of precursors and catalysts, were characterized. The Co-Mo nanoparticles phase composition as well as their size and dispersion were determined using X-ray absorption spectroscopy utilizing synchrotron radiation, electron microscopy, and X-ray scattering. The catalytic activity was tested in the ammonia synthesis process under atmospheric pressure. The activity and stability of the supported catalysts were compared with unsupported cobalt molybdenum nitride Co3Mo3N, revealing the superiority of the present approach.
KW - Ammonia synthesis
KW - Supported catalyst
KW - Cobalt molybdenum nitrides
KW - Scattering
KW - X-ray scattering
KW - Gamma-alumina
KW - Stability
PY - 2025
DO - https://doi.org/10.1016/j.mcat.2025.114907
SN - 2468-8231
VL - 575
SP - 1
EP - 9
PB - Elsevier B.V.
AN - OPUS4-64827
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Gugin, Nikita
T1 - ZIF-8-Based Biocomposites via Reactive Extrusion: Towards Industrial-Scale Manufacturing
N2 - Mechanochemistry offers a solvent-free, sustainable alternative to conventional synthesis of metal-organic framework (MOF) biocomposites, which hold great promise for applications in drug delivery, biocatalysis, and biosensing,[1] yet the field remains limited to batch-type, gram-scale processes that restrict industrial application. To overcome these limitations, we present a scalable solid-state method for producing MOF-based biocomposites via continuous reactive extrusion.
The process begins with rapid model reactions using hand-mixing[2] to encapsulate a variety of biomolecules into zeolitic imidazolate framework-8 (ZIF-8), including proteins, carbohydrates, and enzymes, thereby enabling rapid screening and optimization of reaction conditions. The mild synthesis conditions preserve the catalytic activity of glucose oxidase, confirming the suitability of the method to sensitive biomaterials. Building on this, we translated the batch protocol to twin-screw extrusion,[3] enabling continuous and scalable synthesis of biocomposites such as bovine serum albumin (BSA)@ZIF-8 with tunable protein content. The extrusion process yielded highly crystalline, porous materials with protein loadings of up to 26 wt% and encapsulation efficiencies as high as 96%. The production rate reached 1.2 kg d⁻¹, significantly exceeding previously reported continuous methods.[4]
To demonstrate the industrial viability of the method, we extended the approach to produce shaped ZIF-8 monoliths loaded with hyaluronic acid (HA) in a single-step extrusion. These monoliths retained their structural integrity during washing and released HA without measurable degradation, as confirmed by size-exclusion chromatography.
Our study opens new avenues for the industrial implementation of MOF biocomposites and establishes reactive extrusion as a robust platform for their scalable synthesis and shaping, expanding the toolkit for drug delivery and biocatalytical applications.
T2 - Tag der Chemie 2025
CY - Berlin, Germany
DA - 03.07.2025
KW - Mechanochemistry
PY - 2025
AN - OPUS4-63802
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Voss, Heike
A1 - Zahedi-Azad, Setareh
A1 - Ernst, Owen C.
A1 - Lucaßen, Jan
A1 - Mann, Guido
A1 - Bonse, Jörn
A1 - Boeck, Torsten
A1 - Martin, Jens
A1 - Schmid, Martina
A1 - Krüger, Jörg
T1 - Chemical vapor deposition of indium precursors for solar microabsorbers using continuous laser radiation
BT - A, Materials science & processing
N2 - Localized deposition of indium on an amorphous glass surface covered with a thin molybdenum layer is demonstrated utilizing laser-assisted chemical vapor deposition. A continuous-wave laser causes a temperature rise on the molybdenum layer resulting in the selective aggregation of liquid and ultimately crystalline structures of indium. The formation sites of the indium are determined by the decomposition of gaseous trimethylindium. The deposited indium islands can serve as precursors and could be further processed into compound semiconductors like CuInSe2 for micro-concentrator solar cells. The experimental investigations were supported by theoretical simulations of the laser heating process to calculate the local temperature distribution on the surface of the molybdenum-covered glass substrate.
KW - Laser-assisted Chemical Vapor Deposition
KW - CW Laser
KW - Indium Islands
KW - Micro-concentrator Solar Cell
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-641069
DO - https://doi.org/10.1007/s00339-025-08895-z
SN - 0947-8396
VL - 131
SP - 1
EP - 10
PB - Springer
CY - Berlin ; Heidelberg [u.a.]
AN - OPUS4-64106
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -