TY - JOUR
A1 - Sieg, H.
A1 - Krause, B.-C.
A1 - Kästner, Claudia
A1 - Böhmert, L.
A1 - Lichtenstein, D.
A1 - Tentschert, J.
A1 - Jungnickel, H.
A1 - Laux, P.
A1 - Braeuning, A.
A1 - Fessard, V.
A1 - Thünemann, Andreas
A1 - Luch, A.
A1 - Lampen, A.
T1 - Cellular Effects of In Vitro-Digested Aluminum Nanomaterials on Human Intestinal Cells
N2 - Aluminum (Al) can be taken up from food, packaging, or the environment and thus reaches the human gastrointestinal tract. Its toxic potential after oral uptake is still discussed. The fate of different solid and ionic Al species during the passage through the digestive tract is the focus of this research, as well as the cellular effects caused by these different Al species. The present study combines the physicochemical processing of three recently studied Al species (metallic Al0, mineral Al2O3, and soluble AlCl3) in artificial digestion fluids with in vitro cell systems for the human intestinal barrier. Inductively coupled plasma mass spectrometry (ICP-MS) and small-angle X-ray scattering (SAXS) methods were used to characterize the Al species in the artificial digestion fluids and in cell culture medium for proliferating and differentiated intestinal Caco-2 cells. Cytotoxicity testing and cellular impedance measurements were applied to address the effects of digested Al species on cell viability and cell proliferation. Microarray-based transcriptome analyses and quantitative real-time PCR were conducted to obtain a deeper insight into cellular mechanisms of action and generated indications for cellular oxidative stress and an influence on xenobiotic metabolism, connected with alterations in associated signaling pathways. These cellular responses, which were predominantly caused by formerly ionic Al species and only at very high concentrations, were not impacted by artificial digestion. A two-directional conversion of Al between ionic species and solid particles occurred throughout all segments of the gastrointestinal tract, as evidenced by the presence of nanoscaled particles. Nevertheless, this presence did not increase the toxicity of the respective Al species.
KW - SAXS
KW - Small-angle X-ray scattering
KW - Nanoparticle
PY - 2020
DO - https://doi.org/10.1021/acsanm.9b02354
VL - 3
IS - 3
SP - 2246
EP - 2256
PB - American Chemical Society
AN - OPUS4-50632
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Sieg, H.
A1 - Klusmann, L.
A1 - Ellermann, A. L.
A1 - Böhmert, L.
A1 - Thünemann, Andreas
A1 - Braeuning, A.
T1 - Counterions determine uptake and effects of aluminum in human intestinal and liver cells
N2 - Aluminum (Al) is highly abundant in the biosphere and can occur in different physico-chemical states. It is present in human food and undergoes transitions between dissolved and particulate species during the passage of the gastrointestinal tract. Moreover, in a complex matrix such as food different inorganic and organic counterions can affect the chemical behavior of Al following oral uptake.
In this work, the effects of different counterions, namely chloride, citrate, sulfate, lactate and acetylacetonate, on Al uptake and toxicity in the human intestine are studied. The respective Al salts showed different dissolution behavior in biological media and formed nanoscaled particles correlating in reverse with the amount of their dissolved fraction. The passage through the intestinal barrier was studied using a Caco-2 Transwell® system, showing counterion-dependent variance in cellular uptake and transport. In addition, Al toxicity was investigated using Al species (Al3+, metallic Al0 and oxidic γAl2O3 nanoparticles) and counterions individually or in mixtures on Caco-2 and HepG2 cells. The strongest toxicity was observed using a combination of Al species, depending on solubility, and the lipophilic counterion acetylacetonate. Notably, only the combination of both led to toxicity, while both substances individually did not show toxic effects. A toxification of previously non-toxic Al-species by the presence of acetylacetonate is shown here for the first time. The dependency on the concentration of free Al ions was demonstrated using sodium hydrogen phosphate, which was able to counteract the toxic effects by complexing free Al ions.
These findings, using Al salts as an example for a common food contaminant, underline the importance of a consideration of the chemical properties of human nutrition, especially dissolution and hydrophobicity, which can significantly influence the cellular uptake and effects of xenobiotic substances.
KW - SAXS
KW - Small-angle X-ray scattering
KW - Nanoparticle
PY - 2022
DO - https://doi.org/10.1016/j.tiv.2021.105295
VL - 79
SP - 1
EP - 7
PB - Elsevier
AN - OPUS4-54110
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 - Shipov, A.
A1 - Zaslansky, P.
A1 - Riesemeier, Heinrich
A1 - Segev, G.
A1 - Atkins, A.
A1 - Kalish-Achrai, N.
A1 - Weiner, S.
A1 - Shahar, R.
T1 - The influence of estrogen deficiency on the structural and mechanical properties of rat cortical bone
N2 - Background. Post-menopausal osteoporosis is a common health problem worldwide, most commonly caused by estrogen deficiency. Most of the information regarding the skeletal effects of this disease relates to trabecular bone, while cortical bone is less studied. The purpose of this study was to evaluate the influence of estrogen deficiency on the structure and mechanical properties of cortical bone.
Methods. Eight ovariectomized (OVH) and eight intact (control) Sprague Dawley rats were used. Structural features of femoral cortical bone were studied by light microscopy, scanning electron microscopy and synchrotron-based microcomputer-tomography and their mechanical properties determined by nano-indentation.
Results. Cortical bone of both study groups contains two distinct regions: organized
circumferential lamellae and disordered bone with highly mineralized cartilaginous islands. Lacunar volume was lower in the OVH group both in the lamellar and disorganized regions (182 ± 75 µm3 vs 232 ± 106 µm3 , P < 0.001 and 195 ± 86 µm3 vs. 247 ± 106 µm3 , P < 0.001, respectively). Lacunar density was also lower in both bone regions of the OVH group (40 ± 18 ×103 lacunae/mm3 vs. 47 ± 9×103 lacunae/mm3
in the lamellar region, P = 0.003 and 63 ± 18×103 lacunae/mm3
vs. 75 ± 13×103 lacunae/mm3 in the disorganized region, P < 0.001). Vascular canal volume was lower in the disorganized region of the bone in the OVH group compared to the same Region in the control group (P < 0.001). Indentation moduli were not different between the study groups in both bone regions.
Discussion. Changes to cortical bone associated with estrogen deficiency in rats require high-resolution methods for detection. Caution is required in the application of These results to humans due to major structural differences between human and rat bone.
KW - Estrogen
KW - Disorganized bone
KW - Rat
KW - Lacunae
KW - Ovariectomy
PY - 2021
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-520798
DO - https://doi.org/10.7717/peerj.10213
VL - 9
SP - e10213
AN - OPUS4-52079
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - GEN
A1 - Shard, A. G.
A1 - Hodoroaba, Vasile-Dan
A1 - Unger, Wolfgang
ED - Hodoroaba, Vasile-Dan
ED - Unger, Wolfgang
ED - Shard, A. G.
T1 - Introduction
N2 - The purpose of this book is to provide a comprehensive collection of analytical methods that are commonly used to measure nanoparticles, providing information on one, or more, property of importance. The chapters provide up-to-date information and guidance on the use of these techniques, detailing the manner in which they may be reliably employed. Within this chapter, we detail the rationale and context of the whole book, which is driven by the observation of a low level of reproducibility in nanoparticle research. The aim of the book is to encourage awareness of both the strengths and weaknesses of the various methods used to measure nanoparticles and raise awareness of the range of methods that are available. The editors of the book have, for many years, been engaged in European projects and standardization activities concerned with nanoparticle analysis and have identified authors who are experts in the various methods included within the book. This has produced a book that can be used as a definitive guide to current best practice in nanoparticle measurement.
KW - Nanoparticles
KW - Size distribution
KW - Shape
KW - Chemistry
KW - Coating
KW - Concentration
KW - Standards
KW - Charge
KW - Characterisation
PY - 2020
SN - 978-0-12-814182-3
DO - https://doi.org/10.1016/B978-0-12-814182-3.00001-8
SP - 1
EP - 6
PB - Elsevier
CY - Amsterdam
AN - OPUS4-50166
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Shanmugam, Sankaran
A1 - Peterlechner, Martin
A1 - Iskandar, Mohamad Riza
A1 - Saikia, Ujjal
A1 - Kulitckii, Vladislav
A1 - Lipińska-Chwałek, Marta
A1 - Mayer, Joachim
A1 - Rösner, Harald
A1 - Hickel, Tilmann
A1 - Divinski, Sergiy V.
A1 - Wilde, Gerhard
T1 - Coherent twin-oriented Al3Sc-based precipitates in Al matrix
N2 - Al3(Sc,Zr,Ti) nanoparticles with an ideal twin-type orientation relationship to Al host matrix were found in cold-rolled and subsequently annealed Al-based alloy. Atomic-scale investigations using high-resolution scanning transmission electron microscopy identified particles that form prominent coherent (111) twin-type interfaces along their longer facets and semi-coherent twin interfaces on their shorter facets. Ab-initio calculations showed that a coherent Al/Al3Sc twin-like phase boundary corresponds to a local energy minimum. A model is proposed explaining the formation of the twin orientation relationship of an Al3Sc nanoparticle with the Al host matrix.
KW - Al-based alloy
KW - Precipitation
KW - Twin orientation relationship
KW - Ab initio calculations
KW - Transition electron microscopy
PY - 2023
DO - https://doi.org/10.1016/j.scriptamat.2023.115351
SN - 1359-6462
VL - 229
SP - 1
EP - 6
PB - Elsevier BV
AN - OPUS4-58789
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Sestan, A.
A1 - Sreekala, L.
A1 - Markelj, S.
A1 - Kelemen, M.
A1 - Zavasnik, J.
A1 - Liebscher, C.
A1 - Dehm, G.
A1 - Hickel, Tilmann
A1 - Ceh, M.
A1 - Novak, S.
A1 - Jenus, P.
T1 - Non-uniform He bubble formation in W/W2C composite: Experimental and ab-initio study
N2 - Tungsten-tungsten carbide (W/W2C) composites are considered as possible structural materials for future nuclear fusion reactors. Here, we report on the effect of helium (He) implantation on microstructure evolution of polycrystalline W/W2C composite consolidated by field-assisted sintering technique (FAST), homogenously implanted at room temperature with 1 MeV 4He+ ions at the fluence of 8 × 1016 ions cm−2 and annealed at 1873 K for 20 minutes. Samples were analysed by scanning and transmission electron microscopy to study the presence and size of He bubbles. Monomodal He bubbles in W (30-80 nm) are limited to point defects and grain boundaries, with a considerable void denuded zone (150 nm). Bubbles do not form in W2C, but at the W|W2C interface and are considerably larger (200-400 nm). The experimental observations on He behaviour and migration in W and W2C were assessed by density functional theory (DFT) calculations, suggesting He migration and accumulation in the composite are determined by the effective He-He binding in clusters, which will give rise to decohesion. In the presence of He clusters, the decohesion of bulk W into free surfaces is energetically highly favourable but not sufficient in the W2C; hence bubbles are only observed in W grains and interfaces and not within bulk W2C.
KW - Density functional theory
KW - Tungsten
KW - Ditungsten carbide
KW - FAST
KW - Helium implantation
PY - 2022
DO - https://doi.org/10.1016/j.actamat.2021.117608
VL - 226
SP - 1
EP - 11
PB - Elsevier Ltd.
AN - OPUS4-54364
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Sergievskaya, A.
A1 - Absil, R.
A1 - Chauvin, A.
A1 - Yusenko, Kirill
A1 - Vesely, J.
A1 - Godfroid, T.
A1 - Konsstantinidis, S.
T1 - Sputtering onto liquids: How does the liquid viscosity affect the formation of nanoparticles and metal films?
N2 - This paper reports on the effect of the solvent viscosity on the formation of gold nanoparticles (Au NPs) during Sputtering onto Liquid (SoL) process. All other parameters related to the plasma and the host liquid are kept constant. SoL is a simple highly reproducible approach for preparation of colloidal dispersions of small naked NPs. The properties of the final product are determined by both the sputtering parameters and the host liquid characteristics. As a model system we chose to sputter a gold target by a direct-current magnetron discharge onto a line of polymerized rapeseed oils having similar surface tension (32.6 ― 33.1 mJ·m-2 at RT). It was found that well dispersed Au NPs grow in the bulk solution of oils with low viscosities (below 630 cP at 25 °C) while gold films form onto the surface of high viscosity liquids (more than 1000 cP at 25 °C). The mean diameter of the individual Au NPs slightly increases with oil viscosity and is in range about 2.1―2.5 nm according to transmission electron microscopy.
KW - Liquid spattering
KW - Nanoparticles
PY - 2023
DO - https://doi.org/10.1039/D2CP03038A
SN - 1463-9084
VL - 25
IS - 4
SP - 2803
EP - 2809
PB - RSC Publ.
CY - Cambridge
AN - OPUS4-56562
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Serebrennikova, P.
A1 - Komarov, V.
A1 - Sukhikh, A.
A1 - Khranenko, S.
A1 - Zadesenetz, A.
A1 - Gromilov, S
A1 - Yusenko, Kirill
T1 - [NiEn3](MoO4)0.5(WO4)0.5 co-crystals as single-source precursors for ternary refractory Ni-Mo-W alloys
N2 - The co-crystallisation of [NiEn3](NO3)2 (En = ethylenediamine) with Na2MoO4 and Na2WO4 from a water solution results in the formation of [NiEn3](MoO4)0.5(WO4)0.5 co-crystals. According to the X-ray diffraction analysis of eight single crystals, the parameters of the hexagonal unit cell (space group P–31c, Z = 2) vary in the following intervals: a = 9.2332(3)–9.2566(6); c = 9.9512(12)–9.9753(7) Å with the Mo/W ratio changing from 0.513(3)/0.487(3) to 0.078(4)/0.895(9). The thermal decomposition of [NiEn3](MoO4)0.5(WO4)0.5 individual crystals obtained by co-crystallisation was performed in He and H2 atmospheres. The ex situ X-ray study of thermal decomposition products shows the formation of nanocrystalline refractory alloys and carbide composites containing ternary Ni–Mo–W phases. The formation of carbon–nitride phases at certain stages of heating up to 1000 °C were shown.
KW - Single source precursors
KW - Phase diagrams
PY - 2021
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-540123
DO - https://doi.org/10.3390/nano11123272
VL - 11
IS - 12
SP - 1
EP - 12
PB - MDPI
CY - Basel
AN - OPUS4-54012
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Senges, Gene
A1 - de Oliveira Guilherme Buzanich, Ana
A1 - Lindič, Tilen
A1 - Gully, Tyler A.
A1 - Winter, Marlon
A1 - Radtke, Martin
A1 - Röder, Bettina
A1 - Steinhauer, Simon
A1 - Paulus, Beate
A1 - Emmerling, Franziska
A1 - Riedel, Sebastian
T1 - Unravelling highly oxidized nickel centers in the anodic black film formed during the Simons process by in situ X-ray absorption near edge structure spectroscopy
N2 - The electrofluorination after Simons has been used for the last century to produce everyday life materials. An in situ XANES investigation of the controversially debated black film apparent in the Simons process revealed high-valent nickel centers.
KW - Synchrotron
KW - BAMline
KW - XANES
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-608366
DO - https://doi.org/10.1039/d3sc06081k
SN - 2041-6520
VL - 15
IS - 12
SP - 4504
EP - 4509
PB - Royal Society of Chemistry (RSC)
AN - OPUS4-60836
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 - Seilert, J.
T1 - (Re)engineering functional fat phases – bridging industry and ivory tower
N2 - The crystallization kinetics of commercial structuring fats are determined by the interplay of polymorphic transitions and the formation of mixed crystals involving three primary melting groups: H3, H2M, and H2U. Here, H represents long-chain saturated fatty acids, M denotes medium-chain saturated fatty acids, and U signifies unsaturated fatty acids. Assigning the molecular makeup of structuring fats to the kinetic pathways proves to be a challenging task when dealing with complex mixtures. For example, incorporating H2M triglycerides alters the crystallization pathways substantially by impacting the formation of mixed crystals with and between H3 and H2U triglycerides (TAGs). However, determining the impact of specifics in molecular composition, e.g., fatty acid content and TAG asymmetry, remains a complex challenge when dealing with intricate mixtures. This might be overcome by targeting distinct melting groups and comparing their behavior in complex mixtures to academic replicates.
This study examined four commercial blends with different fatty acids (palmitic versus stearic acid) and varying H3 contents (8% versus 4%), C8-P, C8-S, C4-P, and C4-S. The H2M content and sum of structuring melting groups was kept constant at 9 % and 25 %, respectively. Further, the commercial blends were replicated using synthetic triglycerides representing the main melting groups: PPP and SSS for H3, PLaP and SLaS for H2M and POP and SOS for H2U – resulting in academic blends A8-P, A8-S, A4-P, and A4-S. The crystallization under quiescent conditions at a cooling rate of 3.5 K/min of all eight blends was studied via DSC and time-resolved SAXS/WAXS.
While the P-based commercial blends (C8-P and C4-P) followed typical crystallization routes including an α-β’ transition and clear dependency on H3 content, the S-based counterparts, C8-S and C4-S, showed an α-phase of prolonged stability and evidence of two distinct β’ phases. Differences between commercial and academic blends are discussed.
T2 - 2nd Berlin Symposium on Structured Lipid Phases
CY - Berlin, Germany
DA - 30.09.2024
KW - Lipid phases
KW - Thermal structuring
KW - Crystallography
KW - X-ray scattering
PY - 2024
AN - OPUS4-61334
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Sediqi, Salmin
T1 - Multi-principal element alloy nanoparticle (MPEA-NP) electrocatalysts prepared by pulsed laser ablation for electroreduction of CO2
N2 - Multi-principal element alloy (MPEA) nanoparticle electrocatalysts have the potential to provide a cost-effective and efficient alternative to noble metal electrocatalysts. The chemically complex nature and the high configurational entropy of MPEAs offer advantages in tailoring catalytic activity, product selectivity, and improved stability under harsh reaction conditions. Cu-containing bimetallic catalyst systems have already been demonstrated to lead to a significant increase in catalytic efficiency compared to monometallic systems. Thus, this project aims at the design of Cu-containing MPEAs and nanoparticle electrocatalysts for carbon dioxide reduction reaction.
In this project, base alloys were prepared by means of arc melting with subsequent homogenization treatments and processed by pulsed laser ablation in water and organic solvents into high-purity nanoparticles. The nanoparticles were characterized by means of transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDX). Electrochemical testing was performed both on bulk alloy samples and nanoparticle film coated glassy carbon electrodes by means of cyclic voltammetry (CV), linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS). Nanoparticle coated electrodes have been investigated by means of atomic force microscopy (AFM) and scanning kelvin probe force microscopy (SKPFM) to assure a homogeneous distribution on the electrode surface. The presentation will summarize our initial results on the electrocatalytic activity of Cu-MPEA system for carbon dioxide reduction.
T2 - OPERANDO SPM 2023
CY - Berlin
DA - 15.11.2023
KW - Chemically Complex Materials
KW - CCMat
KW - Electrocatalysis
PY - 2023
AN - OPUS4-59402
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Sediqi, Salmin
T1 - Multi-principal element alloy nanoparticle (MPEA-NP) electrocatalysts prepared by pulsed laser ablation for electroreduction of CO2
N2 - The motivation and overall objective of the project are to develop electrocatalysts that are free of noble metals (e.g., Pt or Au) and are instead based on medium and high entropy alloys (MEA\HEA) of transition metals for the electrochemical reduction of CO2.
The MEA\HEA are multi principal element alloys (MPEAs) consisting of more than three elements with almost equal alloying proportions, forming solid solutions without intermetallic phases. In such a crystal structure, the individual elements are well mixed, and each atom has different nearest neighbours. In catalysis, especially in selectivity, it is precisely this atomic chaos that matters. Due to the large number of possible combinations of elements, these materials offer excellent conditions to tune their functional properties for specific applications.
Especially, catalyst systems in which Cu is combined with another metallic component show a significant increase in catalytic efficiency compared to monometallic systems. Since the catalytic activity, selectivity, and stability of electrocatalysts strongly depend on the size and surface, systematic studies on the influence of the organic stabilizers on heterogeneous catalysis are also of interest.
The focus of this project is to design Cu-based MEA\HEA electrocatalysts on the atomic level. For this purpose, base alloys will be prepared, processed into high-purity nanoparticles by pulsed laser ablation, and tested as electrocatalysts.
T2 - Tag der Chemie 2023
CY - Berlin, Germany
DA - 05.07.2023
KW - Chemically Complex Materials
KW - CCMat
KW - Electrocatalysis
PY - 2023
AN - OPUS4-59403
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Sediqi, Salbin
T1 - Electrocatalytic carbon dioxide reduction on electrodeposited multi principal element alloy (MPEA) catalysts
N2 - The aim of this project is to develop novel noble metal free electrocatalysts that do not rely on critical minerals. We focus on Cu containing multi principal element alloys (MPEAs) improve the efficiency and selectivity of the CO 2 reduction reaction. In general, MPEAs consist of more than three elements that form solid solutions without intermetallic phases. The unique chemical composition and atomic level mixing introduces synergetic effects that play a critical role in electrocat alysis, especially in terms of selectivity. The nearly infinite combinations of elements that can be incorporated into MPEAs provide ample opportunities to tailor their functionality for various applications. This study presents the development of thin films based on CuNiZn MPEAs for CO 2 reduction reaction. The one step electrodeposition of CuNiZn gradient films was performed on carbon electrodes using a Hull cell under constant current or potential. The influence of pH, additives and current density or potential on the composition and mic rostructure of the films was characterized by scanning electron microscopy (SEM) and energy dispersive X ray spectroscopy (EDX). Atomic force microscopy (AFM) was used to study the topography and surface roughness of the CuNiZn films. The results indicate that the addition of ethylenediaminetetraacetic acid (EDTA) and citrate improves the uniformity and adhesion of the thin films. Electrochemical measurements, including cyclic voltammetry, linear sweep voltammetry, and impedance spectroscopy, were performed to investigate the electrocatalytic activity and corrosion resistance of CuNiZn thin films. The CuNiZn gradient films deposited in the Hull cell allow high throughput screening of the electrocatalytic activity. This approach has identified several compositions with high activity, selectivity and stability. Selected electrodeposited films were further processed to nanoparticles by means of pulsed laser ablation in liquids (PLAL). Further analysis thin film and nanoparticle electrocatalysts was performed with in line / at line product monitoring using a rotating disk electrode setup coupled to gas chromatography (GC) and high perform ance liquid chromatography (HPLC). The presentation will summarize the results of our screening study with few deep dives in selected compositions showing superior performance.
T2 - ECASIA 2024
CY - Gothenburg, Sweden
DA - 09.06.2024
KW - CCMat
KW - Energy conversion
KW - Electrodeposition
KW - Electrocatalysis
PY - 2024
AN - OPUS4-62632
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Sediqi, Salbin
T1 - Synthesis and characterization of multi-principal element alloys (MPEAs) for electrocatalysis applications
N2 - The aim of this project is the development of novel, noble metal-free electrocatalysts that do not rely on critical minerals. We focus on multi-principal element alloys (MPEAs), especially combinations involving Cu, to significantly enhance the efficiency of the CO2 reduction reaction. Generally, MPEAs consist of more than three elements, forming solid solutions without intermetallic phases. The unique disordered random structure introduces synergetic effects that play a critical role in electrocatalysis, particularly in terms of selectivity. The neraly-endless combinations of elements that can be incorporated in MPEAs offer ample opportunities to tailor its functionality for various applications.
This study presents the development of thin films based on NiZnCu MPEAs for the CO2 reduction reaction. The one-step electrodeposition of NiZnCu films was performed on Cu substrates in a single bath using a Hull cell under constant current or potential. The influence of pH, additives and current density or potential on the composition and microstructure of the films was characterized by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). Atomic force microscopy (AFM) was used to study the topography and surface roughness of the NiZnCu films. The results indicate that the addition of ethylenediaminetetraacetic acid (EDTA) and citrate enhances the uniformity and adhesion of the thin films.
Electrochemical measurements, including cyclic voltammetry, linear sweep voltammetry and impedance spectroscopy were conducted to study the electrocatalytic activity and the corrosion resistance of NiZnCu thin films. The NiZnCu gradient films deposited in the Hull cell enable high-throughput screening of the electrocatalytic activity. With this approach, multiple compositions showing high activity, selectivity and stability were identified. Further analysis with in line / at line product analysis was performed using a rotating disc electrode setup coupled to gas chromotography (GC) and high-performance liquid chromotography (HPLC). The presentation will summarize the results of our screening study with few deep-dives in selected compositions showing superior performance.
T2 - eMRS 2024 Spring Meeting
CY - Strasbourg, France
DA - 27.05.2024
KW - CCMat
KW - Energy conversion
KW - Electrocatalysis
PY - 2024
AN - OPUS4-62633
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Sechi, R.
A1 - Fackeldey, K.
A1 - Chewle, Surahit
A1 - Weber, M.
T1 - SepFree NMF: A toolbox for analyzing the kinetics of sequential spectroscopic data
N2 - This work addresses the problem of determining the number of components from sequential spectroscopic data analyzed by non-negative matrix factorization without separability assumption (SepFree NMF). These data are stored in a matrix M of dimension “measured times” versus “measured wavenumbers” and can be decomposed to obtain the spectral fingerprints of the states and their evolution over time. SepFree NMF assumes a memoryless (Markovian) process to underline the dynamics and decomposes M so that M = WH, with W representing the components’ fingerprints and H their kinetics. However, the rank of this decomposition (i.e., the number of physical states in the process) has to be guessed from pre-existing knowledge on the observed process. We propose a measure for determining the number of components with the computation of the minimal memory effect resulting from the decomposition; by quantifying how much the obtained factorization is deviating from the Markovian property, we are able to score factorizations of a different number of components. In this way, we estimate the number of different entities which contribute to the observed system, and we can extract kinetic information without knowing the characteristic spectra of the single components. This manuscript provides the mathematical background as well as an analysis of computer generated and experimental sequentially measured Raman spectra.
KW - Kinetics from experiments
KW - Separability assumption
KW - Sequential spectroscopic data
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-559046
DO - https://doi.org/10.3390/a15090297
SN - 1999-4893
VL - 15
IS - 9
SP - 1
EP - 16
PB - MDPI
CY - Basel
AN - OPUS4-55904
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Schönhals, Andreas
A1 - Szymoniak, Paulina
A1 - Kolmangadi, Mohamed Aejaz
A1 - Böhning, Martin
A1 - Zamponi, M.
A1 - Frick, B.
A1 - Appel, M.
A1 - Günther, G.
A1 - Russina, M.
A1 - Alentiev, D.
A1 - Bermeshev, M.
A1 - Zorn, R.
T1 - Microscopic dynamics of highly permeable super glassy polynorbornenes revealed by quasielastic neutron scattering
N2 - The molecular dynamics of addition-type poly(tricyclononenes) with Si-substituted bulky side groups has been investigated by a combination of neutron time-of-flight and neutron backscattering spectroscopy methods on a time scale from 0.1 ps to ca. 3 ns. The investigated poly(tricyclononenes) PTCNSi1 and PTCNSi2g both bear a high microporosity which makes them promising candidates for active separation layers for gas separation membranes. At least for larger gas molecules it is assumed that the pathways for diffusion require an enlargement of pre-existing micropores in terms of an activated zone. A low temperature relaxation process was found for both polymers by the performed neutron scattering experiments. This process was assigned to the methyl group rotation. It was analysed in terms of a jump diffusion in a three-fold potential. The analysis of the dependence of the elastic incoherent structure factor on the scattering vector yields the number of methyl groups which might be immobilized. For PTCNSi1 (3 methyl groups in the monomeric unit) it was found that all methyl groups take part in the methyl group rotation whereas for PTCNSi2g (6 methyl groups in monomeric unit) a considerable number of methyl groups are blocked in their rotation. This immobilization of methyl groups is due to the sterically demanding arrangement of the methyl groups in PTCNSi2g. This conclusion is further supported by the result that the activation energy for the methyl group rotation is three times higher for PTCNSi2g than that of PTCNSi1.
KW - Highly permeably polynorbornenes
KW - Polymers of intrinsic microporosity
KW - Gas separation membranes
KW - Quasielastic neutron scattering
PY - 2021
DO - https://doi.org/10.1016/j.memsci.2021.119972
SN - 0376-7388
VL - 642
PB - Elesevier B.V.
AN - OPUS4-53508
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - BOOK
A1 - Schönhals, Andreas
A1 - Szymoniak, Paulina
T1 - Dynamics of Composite Materials
N2 - Historically, to tune the properties of a polymer or more general soft matter systems by a second phase is not a new concept and dates back to the 40s of the last century. Beside some successes, the improvement of the properties remained somehow limited. The expectations of the enhancement of the properties of composites changed by the developments of Toyota Central research in the 1990s. It was shown that the incorporation of 5 vol% exfoliated layers of a clay system into a polymer leads to a strong improvement of the mechanical and thermal properties. This discovery stimulated a broad research interest of both fundamental and applied character. Today, polymer-based nanocomposites have reached a billion-dollar global market. The corresponding applications span from components for transportation, commodity plastics with enhanced barrier and/or flame retardancy characteristics, to polymers with electrical properties for shielding, electronics, sensors, and solar cells as well as to live science. Important fields are filled rubbers, reinforced thermoplastics, or thermosets for automotive, aircraft/space and marine industries, but also membranes for separation processes as well as barrier layers, just to mention a few.
For a variety of applications, the molecular mobility in nanocomposites is of great importance. This concerns the molecular mobility needed to form a percolating filler network in rubbers used in tires or in composites employed in electric shielding applications. In general, it is also essential for processing polymer-based nanocomposites. Furthermore, separation processes in composite materials for membranes require a certain molecular mobility. This also concern nanodielectrics used in electrical applications or sensors where the mobility of charge carriers can be related to the fluctuations of molecular groups etc. Finally, the molecular mobility can be taken as probe for structure on a molecular scale.
Broadband dielectric spectroscopy is a powerful tool to investigate the molecular mobility in polymer systems. It is due to the extremely broad frequency and sensitivity range that can be covered by this technique. Information about localized and cooperative molecular fluctuations, polarization effects at interfaces, as well as charge transport processes can be deduced. Therefore, this book focusses on broadband dielectric spectroscopy of composite materials. Moreover, the dielectric studies are accompanied by mechanical spectroscopy, advanced calorimetry, NMR techniques, as well as transmission electron microscopy and X-ray scattering investigations.
Besides a brief introduction to (nano)composites, the book aims to address fundamental aspects of the molecular mobility in this innovative group of materials. Selected examples with scientific interest and some cases with high industrial impact were chosen. Due to the breadth of the subject, unfortunately not all topics could be addressed in detail, such as processing for instance.
Berlin, Andreas Schönhals
July 2021 Paulina Szymoniak
KW - Composite materials
KW - Nanocomposites
PY - 2022
SN - 978-3-030-89722-2
SN - 978-3-030-89723-9
DO - https://doi.org/10.1007/978-3-030-89723-9
VL - 2022
SP - 1
EP - 375
PB - Springer Nature
CY - Cham, Switzerland
AN - OPUS4-54538
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CHAP
A1 - Schönhals, Andreas
A1 - Böhning, Martin
A1 - Szymoniak, Paulina
ED - Schönhals, Andreas
ED - Szymoniak, Paulina
T1 - (Nano)Composite Materials—An Introduction
N2 - The chapter gives a brief introduction to (nano)compositecomposite materials having the focus on polymer-based nanocomposites. The different dimensionalities of nanoparticles are introduced, along with their distribution in the matrix.
Different application fields of polymer-based nanocomposites, like flame retardancy, filled rubbers, nanofilled thermosets and thermoplastics, separation membranes and nanodielectrics, are considered in greater detail.
KW - Polymer-based nanocomposites
KW - Nanoparticle
KW - Distribution of nanoparticles
KW - Filled rubbers
KW - Filled thermosets and plastics
KW - Separation membranes
KW - Nanodielectrics
PY - 2022
DO - https://doi.org/10.1007/978-3-030-89723-9_1
SP - 1
EP - 31
PB - Springer
CY - Cham, Switzerland
AN - OPUS4-54565
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Schönhals, Andreas
T1 - Thermal behavior of high preformance polymers - Fast Scanning Calorimetry and more
N2 - The glass tranistion behavior of polymers of intrinsic microporosity and polynornornes is discussed.
T2 - Flash DSC Conference 2021
CY - Online meeting
DA - 06.12.2021
KW - Polymer of Intrisic Maicroporosity
KW - Highly permeable polynorbornenes
PY - 2021
AN - OPUS4-53938
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Schönhals, Andreas
T1 - Multiple glassy dynamics of a homologous series of triphenylene-based columnar liquid crystals – A study by broadband dielectric spectroscopy, advanced calorimetry and Neutron Scattering
N2 - Hexakis(n-alkyloxy)triphenylene) (HATn) consisting of an aromatic triphenylene core and alkyl side chains are model discotic liquid crystal (DLC) systems forming a columnar mesophase. In the mesophase, the molecules of HATn self-assemble in columns, which has one-dimensional high charge carrier mobility along the columns. Here, a homologous series of HATn with different length of the alkyl chain (n=5,6,8,10,12) is investigated using differential scanning calorimetry (DSC), broadband dielectric spectroscopy (BDS) and advanced calorimetric techniques including fast scanning calorimetry (FSC) and specific heat spectroscopy (SHS). The investigation of the phase behavior was done utilizing DSC experiments and the influence of the alkyl chain length on the phase behavior was revealed. By the dielectric investigations probing the molecular mobility, a γ-relaxation due to localized fluctuations as well as two glassy dynamics the αcore and αalkyl relaxation were observed in the temperature range of the plastic crystalline phase. Moreover, the observed glassy dynamics were further studied employing advanced calorimetry. All observed relaxation processes are attributed to the possible specific molecular fluctuations and discussed in detail. From the results a transition at around n=8 from a rigid constrained (n=5,6) to a softer system (n=10,12) on a molecular lenght scale was revealed with increasing alkyl chain length. A counterbalance of two competing effects of a polyethylene like behavior of the alkyl chains in the intercolumnar domains and self-organized confinement is discussed in the context of a hindered glass transition.
T2 - 11th Conferenz on Broadband Dielectric Spectroscopy and its Applications
CY - San Sebastian, Spain
DA - 04.09.2022
KW - Discotic Liquid Crystals
PY - 2022
AN - OPUS4-55672
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Schönhals, Andreas
T1 - Inelastic and Quasielastic Neutron Scattering Experiments on Mircroporous Membranes for Green Separation processes
N2 - Polymers with intrinsic microporosity are promising candidates for the active separation layer in gas separation membranes. These polymers are characterized by a high permeability and reasonable permselectivity. The reasonable permselectivity of these materials is somehow surprising because for microporous systems a more Knudsen-like diffusion is expected rather than a size dependent temperature activated sieving process. It was argued in the framework of a random gate model that molecular fluctuations on a time scale from ps to ns are responsible for the permselectivity.
Here a series of microporous polynorbornenes with bulky SiMe3 side groups and a rigid backbone is considered which have different microporosities characterized by BET surface area values.
First inelastic time-of-flight neutron scattering measurements were carried out to investigate the low frequency density of state (VDOS). The measured data show the characteristic low frequency excess contribution to the VDOS above the Debye sound wave level, generally known as the Boson peak in glass-forming materials. It was found that the maximum position of the Boson peak correlates with the BET surface area.
For two selected comparable polynorbornenes elastic scans as well as QENS measurements by a combination of neutron time-of-flight and backscattering were carried out. A low temperature relaxation process was found for both polymers. This process was assigned to the methyl group rotation. It was analysed in terms of a jump diffusion in a three-fold potential. The analysis of the dependence of the elastic incoherent structure factor on the scattering vector yields the number of methyl groups which might be immobilized.
T2 - QENS / WINS 2022
CY - San Sebastian, Spain
DA - 23.05.2022
KW - Polymers of intrinsic Microporosity
PY - 2022
AN - OPUS4-55673
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Schönhals, Andreas
T1 - Inelastic and Quasielastic Neutron Scattering Experiments on Mircroporous Membranes for Green Separation processes
N2 - Polymers with intrinsic microporosity are promising candidates for the active separation layer in gas separation membranes. These polymers are characterized by a high permeability and reasonable permselectivity. The latter point is somehow surprising because for microporous systems a more Knudson-like diffusion is expected then a size dependent temperature activated sieving process. It was argued in the framework of a random gate model that molecular fluctuations on a time scale from ps to ns are responsible for the permselectivity.
Her a series of microporous polynorbornenes with bulky Si side groups and a rigid backbone are considered which have different microporosity characterized by BET surface area values.
First inelastic time-of-flight neutron scattering measurements were carried out to investigate the low frequency density of state (VDOS). The measured data show the characteristic low frequency excess contribution to the VDOS above the Debye sound wave level, generally known as the Boson peak in glass-forming materials. It was found the maximum position of the Boson peak correlates with the BET surface area value.
For two selected comparable polynorbornenes elastic scans as well as QENS measurements by a combination of neutron time-of-flight and backscattering are carried out. A low temperature relaxation process was found for both polymers. This process was assigned to the methyl group rotation. It was analysed in terms of a jump diffusion in a three-fold potential. The analysis of the dependence of the elastic incoherent structure factor on the scattering vector yields the number of methyl groups which might be immobilized.
T2 - MLZ Conference 2022: Neutrons for mobility
CY - Lengries, Germany
DA - 31.05.2022
KW - Polymers of intrinsic Microporosity
PY - 2022
AN - OPUS4-55674
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Schönhals, Andreas
T1 - Physical investigations on Super glassy Polymers having possible applications in gas Separation Membranes
N2 - The properties of polymers of intrinsic microporosity were investigated by fast scanning calorimetry, dielectric spectroscopy and neutron scattering
T2 - University of Pennsylvania
CY - Online meeting
DA - 25.01.2021
KW - Polymer of intrisic microporosity
PY - 2021
AN - OPUS4-52065
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Schönhals, Andreas
T1 - Inelastic neutron scattering as a tool to investigate polymers of intrinsic microporosity for green membrane processes and electronic applications
N2 - Polymers with intrinsic microporosity are promising candidates for the active separation layer in green gas separation membranes and as active materials for electronic applicatons. Here, by means of inelastic neutron scattering, the vibrational density of states (VDOS) and the molecular mobility were investigated for PIM-1, the prototypical polymer with intrinsic microporosity. The results are compared to data measured for a more conventional high-performance polyimide used in gas separation membranes (Matrimid).
The measured data show the characteristic low frequency excess contribution to the VDOS above the Debye sound wave level, generally known as the Boson peak in glass-forming materials. In comparison to the Boson peak of Matrimid, that of PIM-1 is shifted to lower frequencies. This shift is discussed considering the microporous, sponge-like structure of PIM-1 as providing a higher compressibility at the molecular scale than for conventional polymers.
Elastic fixed window scans were measured on a neutron backscattering spectrometer to have an overview about the molecular dynamics at a time scale of ca. 1 ns. The temperature dependence of the estimated mean squared displacement shows a step-like increase in the temperature range from 100 K to 250 K indicating the onset of some molecular mobility. The nature of this motional process was analysed in detail by quasielastic neutron scattering combining Time-of-Flight and backscattering where the data are discussed with regard to both the q- and the temperature dependence.
T2 - Symposium on Large Scale Facilities
CY - Berlin, Germany
DA - 09.03.2020
KW - Polymer membranen
PY - 2020
AN - OPUS4-50546
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Schwibbert, Karin
A1 - Richter, Anja
A1 - Krüger, Jörg
A1 - Bonse, Jörn
T1 - Laser-Textured Surfaces: A Way to Control Biofilm Formation?
N2 - Bacterial biofilms pose serious problems in medical and industrial settings. One of the major societal challenges lies in the increasing resistance of bacteria against biocides used in antimicrobial treatments, e.g., via overabundant use in medicine, industry, and agriculture or cleaning and disinfection in private households. Hence, new efficient bacteria-repellent strategies avoiding the use of biocides are strongly desired. One promising route to achieve bacteria-repellent surfaces lies in the contactless and aseptic large-area laser-processing of technical surfaces. Tailored surface textures, enabled by different laser-processing strategies that result in topographic scales ranging from nanometers to micrometers may provide a solution to this challenge. This article presents a current state-of-the-art review of laser-surface subtractive texturing approaches for controlling the biofilm formation for different bacterial strains and in different environments. Based on specific properties of bacteria and laser-processed surfaces, the challenges of anti-microbial surface designs are discussed, and future directions will be outlined.
KW - Antibacterial surfaces
KW - Biofilms
KW - Laser processing
KW - Laser-induced periodic surface structures (LIPSS)
KW - Microbial adhesions
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-588260
DO - https://doi.org/10.1002/lpor.202300753
SN - 1863-8899
SP - 1
EP - 41
PB - Wiley-VCH GmbH
CY - Weinheim
AN - OPUS4-58826
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - VIDEO
A1 - Schwibbert, Karin
A1 - Richter, Anja
A1 - Bonse, Jörn
T1 - BioCombs4Nanofibers: From nanofibers over spiders to bacteria
N2 - This 6 minute long MP4-video presents some key results of the European research project "BioCombs4Nanofibers" to the broader public. Inspired by nature, some concepts of certain types of spiders are transferred to technology in order to develop bacteria-repellent surfaces through laser surface nanostructuring.
Funding notice: This study was funded by the European Union's research and innovation program under the FET Open grant agreement No. 862016 (BioCombs4Nanofibers, http://biocombs4nanofibers.eu).
KW - Antiadhesive surfaces
KW - Laser-induced periodic surface structures (LIPSS)
KW - Cribellate spiders
KW - Bacterial adhesion tests
KW - Bacteria-repellent surfaces
PY - 2022
UR - https://download.jku.at/org/7kM/xyU/BioCombs4Nanofibers/D5.6_video%20for%20the%20broader%20public_23.03.2022.mp4
UR - https://www.jku.at/en/biocombs4nanofibers/dissemination/
DO - https://doi.org/10.26272/opus4-54939
PB - Bundesanstalt für Materialforschung und -prüfung (BAM)
CY - Berlin
AN - OPUS4-54939
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 - JOUR
A1 - Schutter, Jan David
A1 - Eberhardt, Karl
A1 - Elert, Anna Maria
A1 - Radnik, Jörg
A1 - Geißler, Daniel
A1 - Özcan Sandikcioglu, Özlem
T1 - Synthesis and characterization of lipopolysaccharide (LPS) anchored polystyrene microparticles as a synthetic model system for attachment studies
N2 - Outer membrane lipopolysaccharides (LPS) play a crucial role in determining attachment behavior and pathogenicity of bacteria. The aim of this study was to develop a simple procedure for anchoring bacterial lipopolysaccharides to polystyrene (PS) microparticles as a model system for in situ attachment studies. By using a swellcapture methodology, commercially available LPS of Pseudomonas aeruginosa (strain ATCC 27316 serotype 10.22) was anchored onto PS microparticles in a proof-of-concept study. A detailed chemical and morphological characterization has proven the success of LPS incorporation. It was shown that the coverage and structure of the LPS film was concentration dependent. The procedure can easily be adapted to LPS of other bacterial strains to generate a synthetic model toolkit for attachment studies.
KW - Bacterial lipopolysaccharides
KW - Pseudomonas aeruginosa
KW - Polystyrene microparticles
KW - Swell-capture
KW - Biomimicry
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-579818
DO - https://doi.org/10.1016/j.colsurfb.2023.113301
SN - 0927-7765
VL - 226
SP - 1
EP - 7
PB - Elsevier B.V.
AN - OPUS4-57981
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Schusterbauer, Robert
A1 - Schünemann, Pia
A1 - Nickl, Philip
A1 - Er, Jasmin
A1 - Kämmer, Victoria
A1 - Junge, Florian
A1 - Fazzani, Salim
A1 - Mrkwitschka, Paul
A1 - Meermann, Björn
A1 - Haag, Rainer
A1 - Donskyi, Ievgen
T1 - Bifunctional Reduced Graphene Oxide Derivatives for PFOA Adsorption
N2 - Innovative materials are crucial for removing persistent pollutants per‐ and polyfluorinated alkyl substances (PFAS) from water. Here, a novel bifunctional reduced graphene oxide (TRGO) adsorbent is developed and characterized by advanced surface sensitive methods. Compared to pristine TRGO, the functionalized TRGO shows markedly improved PFAS removal efficiency and demonstrates strong potential for water purification applications.
KW - Adsorber
KW - PFAS
KW - HR-CS-GFMAS
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-651238
DO - https://doi.org/10.1002/ceur.202500240
SN - 2751-4765
SP - 1
EP - 7
PB - Wiley VHC-Verlag
AN - OPUS4-65123
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Schusterbauer, Robert
A1 - Mrkwitschka, Paul
A1 - Sahre, Mario
A1 - Corrao, Elena
A1 - Zurutuza, Amaia
A1 - Doolin, Alexander
A1 - Pellegrino, Francesco
A1 - Radnik, Jörg
A1 - Donskyi, Ievgen S.
A1 - Hodoroaba, Vasile-Dan
T1 - Correlative Chemical Imaging to Reveal the Nature of Different Commercial Graphene Materials
N2 - Proper physicochemical characterization of advanced materials and complex industrial composites remains a significant challenge, particularly for nanomaterials, whose nanoscale dimensions and mostly complex chemistry challenge the analysis. In this work, we employed a correlative analytical approach that integrates atomic force microscopy (AFM), scanning electron microscopy (SEM) coupled with energy‐dispersive X‐ray spectroscopy (EDS), time‐of‐flight secondary ion mass spectrometry (ToF‐SIMS), Auger electron spectroscopy (AES), and Raman spectroscopy. This combination enables detailed chemical and structural characterization with sub‐micrometer spatial resolution. Three commercial graphene‐based materials of varying complexity were selected and investigated to test the analytical performance of this approach. Furthermore, one of the commercial graphene oxide samples was chemically functionalized via amination and fluorination. This allowed us to assess how surface modifications influence both the material properties and the limits of the applied analytical techniques.
KW - Analytical methods
KW - Commercial products
KW - Correlative analysis
KW - Graphene
KW - Surface imaging
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-654765
DO - https://doi.org/10.1002/smtd.202502344
SN - 2366-9608
SP - 1
EP - 10
PB - Wiley VHC-Verlag
AN - OPUS4-65476
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Schusterbauer, Robert
T1 - Correlative chemical imaging to reveal the nature of different commercial graphene materials
N2 - Since the original report in 2004 by Novoselov and Geim, Graphene gained incredible attention due to its fascinating properties. In the past 20 years, the synthesis and functionalization of graphene has evolved significantly[3]. Different synthesis techniques were developed which led to other graphenerelated materials such as graphene oxide (GO) or elemental-doped graphene. Further chemical functionalization can enhance but also alter or reduce specific properties of the graphene. To reveal the nature of these materials a proper physico‑chemical characterization with different analytical techniques is crucial.
Single-layer GO flakes kindly provided by Graphenea (Spain) were prepared for systematic image analysis. These flakes were disposed on an alignment-marked SiO2 substrate and correlatively imaged by scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), time-of-flight secondary ion mass spectrometry (ToF-SIMS) and Raman spectroscopy. The high lateral resolution and/ or extreme surface sensitivity of the mentioned
techniques is necessary to explore monolayers. The ToF-SIMS images match well with the SEM and AFM images and provide information about the chemistry. With 2D Raman spectroscopy it is possible to differentiate between the number of stacked single-layer flakes. This is visualized in a 3D image (Figure b). Well-defined GO flakes could be used as a reference material for imaging of graphene-like structures but also of other types of 2D materials.
In addition to these monolayer GO flakes, commercial graphene-containing inks (Haydale) with a more complex morphology were also correlatively imaged. ToF-SIMS and SEM images were merged to identify the origin of different chemical fragments. The findings correlate closely with the expectation that the specific functionalizations (with fluorine and nitrogen as marker elements) are present only on the graphene flakes as presumed from the SEM images. Energy-dispersive X-ray spectroscopy (EDX) supports these results, yet with a much lower sensitivity compared to ToF-SIMS.
T2 - MaterialsWeek 2024
CY - Limassol, Cyprus
DA - 17.06.2024
KW - Graphene oxide flakes
KW - ToF-SIMS
KW - SEM
KW - Raman
KW - Correlative imaging
PY - 2024
AN - OPUS4-60681
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Schusterbauer, Robert
T1 - Correlative chemical imaging to reveal the nature of different commercial graphene materials
N2 - Since the original report in 2004 by Novoselov and Geim, Graphene gained incredible attention due to its fascinating properties. In the past 20 years, the synthesis and functionalization of graphene has evolved significantly[3]. Different synthesis techniques were developed which led to other graphenerelated materials such as graphene oxide (GO) or elemental-doped graphene. Further chemical functionalization can enhance but also alter or reduce specific properties of the graphene. To reveal the nature of these materials a proper physico‑chemical characterization with different analytical techniques is crucial.
Single-layer GO flakes kindly provided by Graphenea (Spain) were prepared for systematic image analysis. These flakes were disposed on an alignment-marked SiO2 substrate and correlatively imaged by scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), time-of-flight secondary ion mass spectrometry (ToF-SIMS) and Raman spectroscopy. The high lateral resolution and/ or extreme surface sensitivity of the mentioned
techniques is necessary to explore monolayers. The ToF-SIMS images match well with the SEM and AFM images and provide information about the chemistry. With 2D Raman spectroscopy it is possible to differentiate between the number of stacked single-layer flakes. This is visualized in a 3D image (Figure b). Well-defined GO flakes could be used as a reference material for imaging of graphene-like structures but also of other types of 2D materials.
In addition to these monolayer GO flakes, commercial graphene-containing inks (Haydale) with a more complex morphology were also correlatively imaged. ToF-SIMS and SEM images were merged to identify the origin of different chemical fragments. The findings correlate closely with the expectation that the specific functionalizations (with fluorine and nitrogen as marker elements) are present only on the graphene flakes as presumed from the SEM images. Energy-dispersive X-ray spectroscopy (EDX) supports these results, yet with a much lower sensitivity compared to ToF-SIMS.
T2 - ECASIA 2024
CY - Gothenburg, Sweden
DA - 09.06.2024
KW - Correlative imaging
KW - ToF-SIMS
KW - SEM
KW - Graphene oxide flakes
KW - Raman
PY - 2024
AN - OPUS4-60680
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Scholtz, Lena
A1 - Tavernaro, Isabella
A1 - Eckert, J. G.
A1 - Lutowski, Marc
A1 - Geißler, Daniel
A1 - Hertwig, Andreas
A1 - Hidde, Gundula
A1 - Bigall, N. C.
A1 - Resch-Genger, Ute
T1 - Influence of nanoparticle encapsulation and encoding on the surface chemistry of polymer carrier beads
N2 - Surface-functionalized polymer beads encoded with molecular luminophores and nanocrystalline emitters such as semiconductor nanocrystals, often referred to as quantum dots (QDs), or magnetic nanoparticles are broadly used in the life sciences as reporters and carrier beads. Many of these applications require a profound knowledge of the chemical nature and total number of their surface functional groups (FGs), that control bead charge, colloidal stability, hydrophobicity, and the interaction with the environment and biological systems. For bioanalytical applications, also the number of groups accessible for the subsequent functionalization with, e.g., biomolecules or targeting ligands is relevant. In this study, we explore the influence of QD encoding on the amount of carboxylic acid (COOH) surface FGs of 2 μm polystyrene microparticles (PSMPs). This is done for frequently employed oleic acid and oleylamine stabilized, luminescent core/shell CdSe QDs and two commonly used encoding procedures. This included QD addition during bead formation by a thermally induced polymerization reaction and a post synthetic swelling procedure. The accessible number of COOH groups on the surface of QD-encoded and pristine beads was quantified by two colorimetric assays, utilizing differently sized reporters and electrostatic and covalent interactions. The results were compared to the total number of FGs obtained by a conductometric titration and Fourier transform infrared spectroscopy (FTIR). In addition, a comparison of the impact of QD and dye encoding on the bead surface chemistry was performed. Our results demonstrate the influence of QD encoding and the QD-encoding strategy on the number of surface FG that is ascribed to an interaction of the QDs with the carboxylic acid groups on the bead surface. These findings are of considerable relevance for applications of nanoparticle-encoded beads and safe-by-design concepts for nanomaterials.
KW - Optical spectroscopy
KW - Particle
KW - Optical assay
KW - IR spectroscopy
KW - Fluorescence
KW - Quantum yield
KW - Quality assurance
KW - Nano
KW - Synthesis
KW - Surface chemistry
KW - Quantification
KW - Method
KW - Conductometry
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-581502
DO - https://doi.org/10.1038/s41598-023-38518-7
SN - 2045-2322
VL - 13
IS - 1
SP - 1
EP - 15
PB - Springer Nature
CY - London
AN - OPUS4-58150
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Scholtz, Lena
T1 - Luminescent, nanoparticle-loaded polymer microparticles - comparing synthesis routes
N2 - Our comparison showed that the route used for the synthesis of luminescent, NP-loaded PSMPs can play a significant role for the luminescence properties, as well as the number of accessible SFGs, and hence subsequent functionalization. This should be considered for future applications.
T2 - Bunsen-Tagung 2023
CY - Berlin, Germany
DA - 05.06.2023
KW - Fluorescence
KW - Polymerization
KW - Microbeads
KW - Quantum dots
KW - Comparison
PY - 2023
AN - OPUS4-57628
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Scholtz, Lena
T1 - Standardized Measurements of Surface Functionalities on Nanoparticles
N2 - Engineered nanoparticles (NPs) with various chemical compositions and surface functionalities are routinely and commonly fabricated for industrial applications such as medical diagnostics, drug delivery, sensing, catalysis, energy conversion and storage, opto-electronics, and information storage. NP function, their interaction with biological species, and also their environmental fate are largely determined by the surface functionalities of the particles. Reliable, reproducible, and standardized surface characterization methods are therefore vital for quality control of NPs, determination of their applicability, and mandatory to meet increasing concerns regarding their safety. In addition, industry as well as international standardization organizations, regulatory agencies, and policymakers need validated and standardized measurement methods and reference materials.
However, methodologies for determining NP surface properties, including the amount, chemical composition, and homogeneity of surface functionalities and coatings are largely non-standardized up until now. 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. The latter, typically less costly methods are often used by SMEs, e.g., for quality control. To validate methods, establish measurement uncertainties, test reference materials, and produce reference data, international interlaboratory comparisons (ILC) on NP surface functionalization measurements are required to provide well characterized test and reference nanomaterials including benchmark values.[1] These needs are addressed by the current European metrology project SMURFnano, involving 12 partners from different National Metrology Institutes, designated and research institutes, two university groups as well as one large company and one SME producing NPs. This project, as well as first results derived from the development of test and reference materials with a well characterized surface chemistry, and ongoing interlaboratory comparisons, will be presented.
T2 - eMRS - Fall Meeting 2025
CY - Warsaw, Poland
DA - 15.09.2025
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 - OPUS4-64243
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 - Schneider, Mike
A1 - Couzinié, Jean-Philippe
A1 - Shalabi, Amin
A1 - Ibrahimkhel, Farhad
A1 - Ferrari, Alberto
A1 - Körmann, Fritz
A1 - Laplanche, Guillaume
T1 - Effect of stacking fault energy on the thickness and density of annealing twins in recrystallized FCC medium and high-entropy alloys
N2 - This work aims to predict the microstructure of recrystallized medium and high-entropy alloys (MEAs and HEAs) with a face-centered cubic structure, in particular the density of annealing twins and their thickness. Eight MEAs and five HEAs from the Cr-Mn-Fe-Co-Ni system are considered, which have been cast, homogenized, cold-worked and recrystallized to obtain different grain sizes. This work thus provides a database that could be used for data mining to take twin boundary engineering for alloy development to the next level. Since the stacking fault energy is known to strongly affect recrystallized microstructures, the latter was determined at 293 K using the weak beam dark-field technique and compared with ab initio simulations, which additionally allowed to calculate its temperature dependence. Finally, we show that all these data can be rationalized based on theories and empirical relationships that were proposed for pure metals and binary Cu-based alloys.
KW - CoCrFeMnNi HEAs and MEAs
KW - Recrystallization
KW - Transmission electron microscopy (TEM)
KW - Electron backscatter diffraction
KW - Grain boundary engineering
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-629346
DO - https://doi.org/10.1016/j.scriptamat.2023.115844
SN - 1359-6462
VL - 240
SP - 1
EP - 6
PB - Elsevier
CY - Amsterdam
AN - OPUS4-62934
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Schmitt, M.
A1 - Altmann, Korinna
A1 - Fengler, Petra
A1 - Gehde, M.
T1 - Air-based polyethylene fragmentation with high yield to form microplastic particles as reference material candidates
N2 - Microplastic particles with sizes between 1 to 1000 μm are widely distributed worldwide. Origin, transport pathways and fate are poorly known, as sampling, sample preparation and detection methods are major challenges. In addition, reference materials that mimic environmental particles are lacking. Most challenging is the yield of MP particle production and the need for resource-intensive grinding with liquid nitrogen. In this paper, a machine is designed to produce aged microplastic particles as reference material candidates with high yield. The machine is based on ultraviolet aging of a thin foil and mechanical fragmentation using clean air. An example of aging and fragmentation of high density polyethylene with additional physical and chemical characterization of shape, size, aging state by carbonyl index and density is presented.
KW - Microplastics
KW - Degradation of polyethylene
KW - Air fragmentation
KW - Microplastics reference material
PY - 2023
DO - https://doi.org/10.1002/appl.202200121
SP - 1
EP - 18
PB - Wiley online library
AN - OPUS4-57203
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Schmidt-Grund, R.
A1 - Sturm, C.
A1 - Hertwig, Andreas
T1 - Ellipsometry and polarimetry - Classical measurement techniques with always new developments, concepts, and applications
N2 - Ellipsometry is a matured experimental method, whose roots reach back into the early phase of modern optics itself. It is often attributed to be invented by Paul Drude in the last decade of the 19th century, but similar techniques had already been applied for years before Drude started his work. With this Special Issue about ellipsometry and related techniques, we hope to bring more attention to this method and advance and propagate it to be used by a broader community. We have collected a good mixture of articles: some texts are more in the line of users’ tutorial and best practice guides; others are intended to show recent developments of the method. With this collection, we also hope to show the generally rapidly expanding possibilities of ellipsometry and polarimetry to draw attention of new users and previously unrelated communities to this valuable tool.
KW - Ellipsometry
KW - Polarimetry
KW - Surfaces
KW - Thin films
KW - Optical analysis
PY - 2022
DO - https://doi.org/10.1515/aot-2022-0025
SN - 2192-8584
SN - 2192-8576
VL - 11
IS - 3-4 (Topical issue: Ellipsometry)
SP - 57
EP - 58
PB - De Gruyter
CY - Berlin
AN - OPUS4-55467
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Schmid, Thomas
A1 - Hodoroaba, Vasile-Dan
T1 - Correlative Analysis by Raman and other Micro & Nanospectroscopic Imaging Techniques
N2 - In the present talk the basics of the Raman spectroscopy and particularly of Raman microscopy are explained. Advantages and disadvantages of the method are highlighted through selected case studies. In the second part of the lecture examples of correlative imaging with electron, X-ray, ion and optical microscopies from micro- to the nanoscale are highlighted.
T2 - Charisma School on Raman Harmonisation
CY - Turin, Italy
DA - 19.10.2022
KW - Raman
KW - Correlative Imaging
KW - Microscopy
KW - Hyperspectral imaging
PY - 2022
UR - https://amdgroup.inrim.it/events/vamas-sc-meeting-47/program-sc47
AN - OPUS4-56094
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Schmalz, Alina
A1 - Eby, Charles Gaston
A1 - Moss, Caitlin
A1 - Bhattacharya, Biswajit
A1 - Emmerling, Franziska
T1 - Thermally Robust 1D Cu(I) Phosphonate Coordination Polymer Exhibiting Enhanced Proton Conductivity via Humidity‐Driven Pathways
N2 - The development of thermally stable solid-state proton conductors (SSPCs) is crucial for advancing energy-conversion devices such as proton-exchange membrane fuel cells (PEMFCs). In this work, we report the solvothermal synthesis and characterization of a novel, 1D Cu(I) coordination polymer, {Cu(ADP)0.5(BPY)}n (BAM-5), based on anthracenediylphosphonate (H2ADP) and 4,40 -bipyridine (BPY). Single-crystal X-ray diffraction revealed that BAM-5 crystallizes in the triclinic space group P1 and shows a 1D ladder structure connected by the H2ADP and organic BPY linkers, which is assembled into a 2D layer via O−H···O hydrogen bonding interactions between uncoordinated oxygen and the O−H of the phosphonate group. Thermogravimetric and dynamic water sorption analysis demonstrated exceptional thermal robustness of BAM-5 until 230°C and notable water affinity. Proton conductivity measurements found increasing proton conductive properties with increasing temperature and relative humidity.The latter is correlated with the material’s water uptake since the structure itself does not contain any permanent lattice water molecules. A maximum proton conductivity of 6.6 × 10−6 S cm−1 was found at 80°C and 98% RH. To the best of our knowledge, no dense, nonporous 1D coordination polymer without lattice or coordinated solvent molecules has shown comparable proton con� ductivity. The high activation energy suggests a combination of both, a Grotthuss-type proton hopping through the hydrogen� bonded framework, and a vehicular process, in which protons are carried along with absorbed water molecules.
KW - Coordination polymers
KW - Phosphonate ligand
KW - Proton conduction
KW - X-ray diffraction
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-651382
DO - https://doi.org/10.1002/zaac.202500187
SN - 0044-2313
SP - 1
EP - 8
PB - Wiley VHC-Verlag
AN - OPUS4-65138
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - CONF
A1 - Schmalz, Alina
T1 - Framework Materials for the Electrocatalytic Reduction of Nitrate to Ammonia
N2 - The electrocatalytic reduction of nitrate to ammonia offers a sustainable alternative to the energy-intensive Haber-Bosch process while simultaneously addressing the pressing issue of nitrate pollution in water sources. Developing efficient catalysts for this reaction is therefore vital for both environmental remediation and green ammonia production. Framework materials such as metal-organic frameworks (MOFs) or metalated covalent organic frameworks (COFs) present an emerging class of electrocatalytic materials due to their high surface area, tunable porosity, and structural modularity. Their ability to incorporate diverse metal centers and functional groups makes them promising candidates for selective and efficient nitrate reduction. In order to change and improve catalytic properties, different synthesis strategies can be pursued, such as metal alloying, doping or calcination. To fully understand and optimize these materials, advanced characterization techniques are essential to correlate structural features with catalytic performance, alongside in-situ methods for real-time mechanistic insights.
T2 - 10th European Crystallography School
CY - Ohrid, North Macedonia
DA - 23.06.2025
KW - Electrocatalysis
KW - Electrochemistry
KW - Framework Materials
KW - Ammonia Synthesis
KW - Nitrate Reduction
PY - 2025
AN - OPUS4-63846
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Schlögl, Johanna
A1 - Goldammer, Ole
A1 - Bader, Julia
A1 - Emmerling, Franziska
A1 - Riedel, Sebastian
T1 - Introducing AFS ([Al(SO3F)3]x) – a thermally stable, readily available, and catalytically active solid Lewis superacid
N2 - This paper introduces the thermally stable, solid Lewis superacid aluminium tris(fluorosulfate) (AFS), that is easy-to-synthesize from commercially available starting materials. Its applicability, e.g. in catalytic C–F bond activations, is shown.
KW - Lewis Acid
KW - C-F activation
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-601001
DO - https://doi.org/10.1039/D4SC01753F
SN - 2041-6520
SP - 1
EP - 7
PB - Royal Society of Chemistry (RSC)
AN - OPUS4-60100
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Schiffmann, J.
A1 - Emmerling, Franziska
A1 - Martins, Ines
A1 - Van Wüllen, L.
T1 - In-situ reaction monitoring of a mechanochemical ball mill reaction with solid state NMR
N2 - We present an approach towards the in situ solid state NMR monitoring of mechanochemical reactions in a ball mill. A miniaturized vibration ball mill is integrated into the measuring coil of a home-built solid state NMR probe, allowing for static solid state NMR measurements during the mechanochemical reaction within the vessel. The setup allows to quantitatively follow the product evolution of a prototypical mechanochemical reaction, the formation of zinc phenylphosphonate from zinc acetate and phenylphosphonic acid. MAS NMR investigations on the final reaction mixture confirmed a reaction yield of 89% in a typical example. Thus, NMR spectroscopy may in the future provide complementary information about reaction mechanisms of mechanochemical reactions and team up with other analytical methods which have been employed to follow reactions in situ, such as Raman spectroscopy or X-ray diffraction.
KW - Mechanochemistry
KW - Solid state NMR
KW - NMR probe Development
PY - 2020
DO - https://doi.org/10.1016/j.ssnmr.2020.101687
VL - 109
SP - 101687
PB - Elsevier Inc.
AN - OPUS4-51283
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - GEN
A1 - Schiek, Manuela
A1 - Minenkov, Alexey
A1 - Hollweger, Sophia
A1 - Duchoslav, Jiri
A1 - Erdene-Ochir, Otgonbayar
A1 - Weise, Matthias
A1 - Ermilova, Elena
A1 - Hertwig, Andreas
T1 - Optical constants of In2O3-SnO2 (Indium tin oxide, ITO)
N2 - Optical constants of In2O3-SnO2 (Indium tin oxide, ITO)
Minenkov et al. 2024: on glass; n,k 0.191–1.69 µm
Optical constants of In2O3-SnO2 (Indium tin oxide, ITO)
Minenkov et al. 2024: on Si wafer, top; n,k 0.191–1.69 µm
Optical constants of In2O3-SnO2 (Indium tin oxide, ITO)
Minenkov et al. 2024: on Si wafer, bottom; n,k 0.191–1.69 µm
KW - Indium Tin Oxide
KW - Optical constants
KW - Magnetron Sputtering
KW - Electrochemical Degradation
KW - Spectroscopic Ellipsometry
PY - 2024
UR - https://refractiveindex.info/?shelf=other&book=In2O3-SnO2&page=Minenkov-glass
UR - https://refractiveindex.info/?shelf=other&book=In2O3-SnO2&page=Minenkov-wafer-top
UR - https://refractiveindex.info/?shelf=other&book=In2O3-SnO2&page=Minenkov-wafer-bottom
PB - Refractiveindex.info
AN - OPUS4-59766
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Schiebel, J.
A1 - Noack, J.
A1 - Rödiger, S.
A1 - Kammel, A.
A1 - Menzel, Friederike
A1 - Schwibbert, Karin
A1 - Weise, Matthias
A1 - Weiss, R.
A1 - Böhm, A.
A1 - Nitschke, J.
A1 - Elimport, A.
A1 - Roggenbuck, D.
A1 - Schierack, P.
T1 - Analysis of three-dimensional biofilms on different material surfaces
N2 - Biofilms cause complications and high costs in both industry and medicine. Of particular interest are bacterial infections of prosthetic materials, which usually cannot be eliminated due to the high antibiotic resistance known for bacteria forming biofilms. The search for new materials and coatings with lower colonization potential and antibacterial activity is of great importance to reduce biofilm formation. However, there is no standardized procedure to examine the colonization characteristics of bacteria in the Biofilm state in situ. Here, we describe an automated epifluorescence microscopy system for the semi-quantitative analysis of three-dimensional (3D) biofilms on various surfaces. To analyze adherent bacteria, three materials (glass, steel and titanium) were incubated with bacteria in a flow chamber system. After fluorescence staining of the bacteria, automated image capturing, quantification of the bacteria, measurement of the colonized area and determination of the 3D biofilm height were carried out by using novel software.
Furthermore, the materials were examined for their surface topography using white light scanning interferometry. Titanium compared to glass showed a significantly higher number of adherent bacteria.
We argue that this was due to the higher microroughness of titanium. The colonized area was in accordance with the number of adherent bacteria and was also significantly larger on titanium coupons compared to glass. Maximum 3D biofilm height on glass coupons was significantly lower compared to the ones on steel and titanium. This novel method enables the standardized, automated investigation of the colonization with bacteria on different materials. This approach can considerably support the characterization of new material surfaces and their innovative coatings by analyzing the amount of attached Bacteria and thickness of biofilms in situ and eliminates the need of conventional cultivation.
KW - Biofilm
KW - Bacterial adhesion
KW - Biofilm quantification
KW - Automated analysis
PY - 2020
DO - https://doi.org/10.1039/D0BM00455C
SP - 1
EP - 11
PB - Royal Society of Chemistry
AN - OPUS4-50815
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Scheurrell, Kerstin
A1 - B. Martins, Inês C.
A1 - Murray, Claire
A1 - Emmerling, Franziska
T1 - Exploring the role of solvent polarity in mechanochemical Knoevenagel condensation: in situ investigation and isolation of reaction intermediates
N2 - Mechanochemistry has proven to be a highly effective method for the synthesis of organic compounds. We studied the kinetics of the catalyst-free Knoevenagel reaction between 4-nitrobenzaldehyde and malononitrile, activated and driven by ball milling. The reaction was investigated in the absence of solvents (neat grinding) and in the presence of solvents with different polarities (liquid-assisted grinding). The reaction was monitored using time-resolved in situ Raman spectroscopy and powder X-ray diffraction (PXRD). Our results indicate a direct relationship between solvent polarity and reaction kinetics, with higher solvent polarity leading to faster product (2-(4-nitrobenzylidone)malononitrile) formation. For the first time, we were able to isolate and determine the structure of an intermediate 2-(hydroxy(4-nitrophenyl)methyl)malononitrile based on PXRD data.
KW - Physical and Theoretical Chemistry
KW - General Physics and Astronomy
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-588071
DO - https://doi.org/10.1039/D3CP02883F
SN - 1463-9076
VL - 25
IS - 35
SP - 23637
EP - 23644
PB - Royal Society of Chemistry (RSC)
AN - OPUS4-58807
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - GEN
A1 - Schaepe, Kaija
A1 - Jungnickel, H.
A1 - Heinrich, Thomas
A1 - Tentschert, J.
A1 - Luch, A.
A1 - Unger, Wolfgang
ED - Hodoroaba, Vasile-Dan
ED - Unger, Wolfgang
ED - Shard, A. G.
T1 - Secondary ion mass spectrometry
N2 - This chapter provides an introduction in secondary ion mass spectrometry as one of the leading surface chemical analysis and imaging techniques with molecular specificity in the field of material sciences. The physical basics of the technique are explained along with a description of the typical instrumental setups and their modes of operation. The application paragraph specifically focuses on nanoparticle analysis by SIMS in terms of surface spectrometry, imaging, analysis in organic and complex media, and depth profiling.
A review of the existing literature is provided, and selected studies are showcased. Limitations and pitfalls as well as current technical developments of SIMS application in nanoparticle surface chemical analysis are equally discussed.
KW - Time-of-flight secondary ion mass spectrometry
KW - Surface chemical analysis
KW - Imaging
KW - Nanomaterials
KW - Nanoparticles
KW - Core-shell
PY - 2020
SN - 978-0-12-814182-3
DO - https://doi.org/10.1016/B978-0-12-814182-3.00025-0
SP - 481
EP - 509
PB - Elsevier
CY - Amsterdam
AN - OPUS4-50187
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -