TY - CONF A1 - Szymoniak, Paulina A1 - Kolmangadi, Mohamed A. A1 - Schönhals, Andreas T1 - Application of Fast Scanning Calorimetry in Soft Matter Research – Two Examples: 1. Polymers for Gas separation membranes 2. Ionic Liquid Crystals N2 - The application of fast scanning calorimetry (FSC) with heating rates in the range from 10 K/s to 10,000 K/s in soft matter research is discussed through two examples. In the first part, FSC is applied to polymers of intrinsic microporosity (PIMs). No glass transition could be measured for these polymers by conventional calorimetry before their degradation. By decoupling the time scales of chemical degradation and the glass transition, it could be shown for the first time that PIMs undergo a glass transition. In the second part, FSC is applied to ionic liquid crystals to investigate their molecular mobility. In order to cover a broad dynamical range, FSC is combined with temperature-modulated differential scanning calorimetry, and temperature-modulated FSC. T2 - Colloqium at the physics department of the Charles university Prague CY - Prague, Czech Republic DA - 12.11.2024 KW - Fast Scanning Calorimetry PY - 2024 AN - OPUS4-61670 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pauw, Brian Richard T1 - Small-angle scattering for everyone: How to unlock the power of this ancient technique N2 - The obscure, yet fundamental technique of scattering can unlock essential information on the fine structure of materials. For you, it can help you understand how your batteries charge, how squid backbones work, or how hundreds of small variations in your syntheses affect your samples. As a nondestructive technique, it also measures your materials *in situ* or operando, as you pull it, heat it, electrify it, or align it one way or another. Scattering can be done using light, X-rays, neutrons, and even electrons, giving you the choice on which probe is best for you. The only downside? Scattering will always remain a complicated technique to do right. The technique gives you only one piece of information: the length distribution of density in your sample. How you interpret this (rather abstract) piece of information is up to you and your samples. Unlike microscopy, where the real-space image can be interpreted almost intuitively and artefacts are easier to spot, in scattering you cannot always easily identify artefacts. Therefore, the only way to do scattering experiments correctly is through rigour and care. For those of us with that particular eccentricity, seeing the rigour and care pay off is exhilarating, and opens the door to a life of happiness and excitement. This lecture will introduce scattering (in particular using X-rays and neutrons), what it is, what you can (and cannot) get out of it, and how to approach your scattering experiment. Regarding the experimental section, it will discuss the five parts that make up a successful scattering experiment based on real-life examples: Preparation: which and how you prepare your samples affects what you can get out of the interpretation Measurement: The machine design and your measurement choices dictates the final quality of your data Correction: Obtaining trustworthy scattering curves will greatly improve the speed and quality of your analysis. Analysis: Do you linearize, use generic scattering models, perform classical least-squares fitting, play with Monte-Carlo analysis or transform your data.. Some tips to help you make a choice. Interpretation: what does the analysis of all your samples tell you? Can you fit the puzzle pieces together to form a piece of knowledge? For further information, please feel free to explore the https://lookingatnothing.com/ weblog, the https://youtube.com/drheaddamage video channel, or by asking me in person or by email for specific questions at brian.pauw@bam.de . Some introductory reading can be found in the following papers: Pauw, B. R. (2013): Everything SAXS: small-angle scattering pattern collection and correction. _J. Phys.: Condens. Matter_ 25: 383201. DOI: [10.1088/0953-8984/25/38/383201](http://dx.doi.org/10.1088/0953-8984/25/38/383201) B. R. Pauw, A. J. Smith, T. Snow, N. J. Terrill, A. F. Thünemann, (2017): The modular SAXS data correction sequence for solids and dispersions, _Journal of Applied Crystallography_, 50: 1800–1811, DOI: [10.1107/S1600576717015096](https://doi.org/10.1107/S1600576717015096) G. J. Smales, B. R. Pauw (2021): The MOUSE project: a meticulous approach for obtaining traceable, wide-range X-ray scattering information. _Journal of instrumentation_ 16 (6) P06034. DOI: [10.1088/1748-0221/16/06/P06034](https://doi.org/10.1088/1748-0221/16/06/P06034) T2 - SAS School at the XIX International Small Angle Scattering Conference CY - Taipei, Taiwan DA - 02.11.2024 KW - X-ray scattering KW - Neutron scattering KW - Scattering KW - X-ray KW - Neutron KW - Introduction KW - Methodology PY - 2024 AN - OPUS4-61623 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pauw, Brian Richard T1 - Chasing perfection: A holistic approach to materials science scattering experiments 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 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… T2 - XIX International Small Angle Scattering Conference CY - Taipei, Taiwan DA - 04.11.2024 KW - Methodology KW - X-ray scattering KW - Data quality KW - Data provenance KW - Data stewardship KW - Lab automation KW - Perfection PY - 2024 AN - OPUS4-61625 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kanerva, M. A1 - Matrenichev, V. A1 - Layer, R. A1 - Takala, T. M. A1 - Laurikainen, P. A1 - Sarlin, E. A1 - Elert, Anna Maria A1 - Yuding, V. A1 - Seitsonen, J. A1 - Ruokolainen, J. A1 - Saris, P. T1 - Comparison of Rosin and Propolis Antimicrobials in Cellulose Acetate Fibers Against Staphylococcus aureus N2 - The quantitative difference in the antibacterial response was measured for pine rosin and propolis against Staphylococcus aureus ATCC 12598. The activity was studied for fibrous networks that form entirely bio-based cellulose-acetate (CA) materials. The analysis considers the effects of bacterial input, additive dosage, solvent type, variation in preparation, as well as the effect of storage time. Based on the results, the electrospun network structure is dependent on the solvent and the concentration of rosin and propolis. Both rosin and propolis improved the cellulose acetate solution processability, yet they formed beads at high concentrations. Rosin and propolis created strong antibacterial properties when these material systems were immersed in the liquid for 24 h at room temperature. The response remained visible for a minimum of two months. The electrospun networks of water and DMAc solvent systems with 1 to 5 wt% rosin content were clearly more efficient (i.e., decrease of 4 to 6 logs in colony forming units per mL) than the propolis networks, even after two months. This efficiency is likely due to the high content of abietic acids present in the rosin, which is based on the Fourier transform infrared spectra. The results of the additional analysis and cell cultivation with dermal fibroblast cells indicated an impairing effect on skin tissue by the rosin at a 1 wt% concentration compared to the pure CA fibers. KW - Electrospinning KW - Rosin KW - Propolis KW - Antibacterial KW - Cellulose acetate PY - 2020 SN - 1930-2126 VL - 15 IS - 2 SP - 3756 EP - 3773 AN - OPUS4-50635 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Stratakis, E. A1 - Bonse, Jörn A1 - Heitz, J. A1 - Siegel, J. A1 - Tsibidis, G.D. A1 - Skoulas, E. A1 - Papadopoulos, A. A1 - Mimidis, A. A1 - Joel, A.-C. A1 - Comanns, P. A1 - Krüger, Jörg A1 - Florian, C. A1 - Fuentes-Edfuf, Y. A1 - Solis, J. A1 - Baumgartner, W. T1 - Laser engineering of biomimetic surfaces N2 - The exciting properties of micro- and nano-patterned surfaces found in natural species hide a virtually endless potential of technological ideas, opening new opportunities for innovation and exploitation in materials science and engineering. Due to the diversity of biomimetic surface functionalities, inspirations from natural surfaces are interesting for a broad range of applications in engineering, including phenomena of adhesion, friction, wear, lubrication, wetting phenomena, self-cleaning, antifouling, antibacterial phenomena, thermoregulation and optics. Lasers are increasingly proving to be promising tools for the precise and controlled structuring of materials at micro- and nano-scales. When ultrashort-pulsed lasers are used, the optimal interplay between laser and material parameters enables structuring down to the nanometer scale. Besides this, a unique aspect of laser processing technology is the possibility for material modifications at multiple (hierarchical) length scales, leading to the complex biomimetic micro- and nano-scale patterns, while adding a new dimension to structure optimization. This article reviews the current state of the art of laser processing methodologies, which are being used for the fabrication of bioinspired artificial surfaces to realize extraordinary wetting, optical, mechanical, and biological-active properties for numerous applications. The innovative aspect of laser functionalized biomimetic surfaces for a wide variety of current and future applications is particularly demonstrated and discussed. The article concludes with illustrating the wealth of arising possibilities and the number of new laser micro/nano fabrication approaches for obtaining complex high-resolution features, which prescribe a future where control of structures and subsequent functionalities are beyond our current imagination. KW - Biomimetic surfaces KW - Laser processing KW - Surface functionalization KW - Bioinspiration KW - Bionic materials PY - 2020 DO - https://doi.org/10.1016/j.mser.2020.100562 SN - 0927-796X VL - 141 SP - 100562-1 EP - 100562-47 PB - Elsevier B.V. AN - OPUS4-50927 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Mezera, Marek A1 - Florian, C. A1 - Römer, G.-W. A1 - Krüger, Jörg A1 - Bonse, Jörn ED - Stoian, R. ED - Bonse, Jörn T1 - Creation of Material Functions by Nanostructuring N2 - Surface nanostructures provide the possibility to create and tailor surface functionalities mainly via controlling their topography along with other chemical and physical material properties. One of the most appealing technologies for surface functionalization via micro- and nanostructuring is based on laser processing. This can be done either via direct contour-shaping of the irradiated material using a tightly focused laser beam or in a self-ordered way that allows employing larger laser beam diameters along with areal scanning to create a variety of laser-induced periodic surface structures (LIPSS). For the latter approach, particularly ultrashort pulsed lasers have recently pushed the borders across long-lasting limitations regarding the minimum achievable feature sizes and additionally boosted up the production times. This chapter reviews the plethora of recently investigated applications of LIPSS—for example, via imposing diffractive or plasmonic structural colors, the management of liquids and surface wetting properties, biomedical and bioinspired functionalities, beneficial effects in tribology for reducing friction and wear, the manipulation of optical scattering and absorption in photovoltaics, or the modification of magnetic or superconducting surface properties in other energy applications. The footprint of the LIPSS-based technology is explored in detail regarding the current state of industrialization, including an analysis of the market and associated LIPSS production costs. KW - Laser-induced periodic surface structures, LIPSS KW - Surface functionalization KW - Nanostructures KW - Microstructures KW - Laser processing PY - 2023 SN - 978-3-031-14751-7 SN - 978-3-031-14752-4 DO - https://doi.org/10.1007/978-3-031-14752-4_23 VL - 239 SP - 827 EP - 886 PB - Springer Nature Switzerland AG CY - Cham, Switzerland AN - OPUS4-57295 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Sokolowski-Tinten, K. A1 - Bonse, Jörn A1 - Barty, A. A1 - Chapman, H.N. A1 - Bajt, S. A1 - Bogan, M.J. A1 - Boutet, S. A1 - Cavalleri, A. A1 - Düsterer, S. A1 - Frank, M. A1 - Hajdu, J. A1 - Hau-Riege, S. A1 - Marchesini, S. A1 - Stojanonovic, N. A1 - Treusch, R. ED - Stoian, R. ED - Bonse, Jörn T1 - In-Situ Observation of the Formation of Laser-Induced Periodic Surface Structures with Extreme Spatial and Temporal Resolution N2 - Irradiation of solid surfaces with intense ultrashort laser pulses represents a unique way of depositing energy into materials. It allows to realize states of extreme electronic excitation and/or very high temperature and pressure and to drive materials close to and beyond fundamental stability limits. As a consequence, structural changes and phase transitions often occur along unusual pathways and under strongly nonequilibrium conditions. Due to the inherent multiscale nature—both temporally and spatially—of these irreversible processes, their direct experimental observation requires techniques that combine high temporal resolution with the appropriate spatial resolution and the capability to obtain good quality data on a single pulse/event basis. In this respect, fourth-generation light sources, namely, short wavelength and short pulse free electron lasers (FELs), are offering new and fascinating possibilities. As an example, this chapter will discuss the results of scattering experiments carried out at the FLASH free electron laser at DESY (Hamburg, Germany), which allowed us to resolve laser-induced structure formation at surfaces on the nanometer to submicron length scale and in temporal regimes ranging from picoseconds to several nanoseconds with sub-picosecond resolution. KW - Laser-induced periodic surface structures, LIPSS KW - Capillary waves KW - Time-resolved scattering KW - Pump-probe experiments KW - Free electron laser PY - 2023 SN - 978-3-031-14751-7 SN - 978-3-031-14752-4 DO - https://doi.org/10.1007/978-3-031-14752-4_6 VL - 239 SP - 257 EP - 276 PB - Springer Nature Switzerland AG CY - Cham, Switzerland AN - OPUS4-57297 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Yusenko, Kirill A1 - Zvereva, V. A1 - Martynova, S. A1 - Asanov, I. A1 - La Fontaine, C. A1 - Roudenko, O. A1 - Gubanov, A. A1 - Plyusnin, P. A1 - Korenev, S. A1 - Asanova, T. T1 - Insight of the thermal decomposition of ammonium hexahalogenoiridates(IV) and hexachloroiridate(III) N2 - Thermal decomposition of (NH4)3[IrCl6]·H2O, (NH4)2[IrCl6] and (NH4)2[IrBr6] in reductive and inert atmospheres has been investigated in situ using quick-EXAFS and temperature-resolved powder X-ray diffraction. For the first time, (NH4)2[Ir(NH3)Cl5] and (NH4)2[Ir(NH3)Br5] have been proven as intermediates of thermal decomposition of (NH4)3[IrCl6]·H2O, (NH4)2[IrCl6] and (NH4)2[IrBr6]. Thermal degradation of (NH4)2[IrCl6] and (NH4)2[IrBr6] is a more complex process as suggested previously and includes simultaneous formation of (NH4)2[Ir(NH3)Cl5] and (NH4)2[Ir(NH3)Br5] intermediates mixed with metallic iridium. In the inert atmosphere, complexes (NH4)[Ir(NH3)2Cl4] and (NH4)[Ir(NH3)2Br4] as well as [Ir(NH3)3Br3] were proposed as possible intermediates before formation of metallic iridium particles KW - Thermal decomposition KW - Iridium compounds KW - EXAFS KW - In situ PXRD PY - 2020 DO - https://doi.org/10.1039/D0CP02743J VL - 22 IS - 40 SP - 22923 EP - 22934 AN - OPUS4-51224 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zutta Villate, J. M. A1 - Viviana Rojas, J. A1 - Hahn, Marc Benjamin A1 - Anselmo Puerta, J. T1 - Synthesis of 198Au nanoparticles sub 10 nm due optimization on local dose by Monte Carlo simulations for cancer treatment N2 - To enhance the biological effects of radiation damage in cancerous cells, we present an alternative approach to the use of gold nanoparticles (AuNP), focusing on the synthesis and characterization of highly monodisperse, spherical radioactive gold nanoparticles 198AuNP. The size of the AuNP size was optimized with the help of Geant4/TOPAS particle scattering simulations, and energy deposition per nm3 per decay for varying radii (2–10 nm) was evaluated. This work is the foundation for ongoing experimental work to evaluate cell death induced by 198AuNP which aims for the use of radioactive gold nanoparticles in cancer treatment. KW - AuNP KW - Beta decay KW - Beta particle KW - Brachytherapy KW - Cancer treatment KW - Nanoparticles KW - Nanoparticle KW - DNA KW - DNA damage KW - Dosimetry KW - Energy deposit KW - Gamma ray KW - Geant4 KW - Geant4-DNA KW - Gold Nanoparticles KW - LEE KW - Low energy electrons KW - MCS KW - Microdosimetry KW - Monte-Carlo simulation KW - NP KW - Synthesis KW - TEM KW - OH radicals KW - Particle scattering KW - Radiation damage KW - Radiationtherapy KW - Radioactive decay KW - Radiolysis KW - Simulation KW - TOPAS KW - TOPAS-nbio PY - 2022 DO - https://doi.org/10.1007/s10967-022-08355-5 SN - 1588-2780 SP - 1 EP - 9 PB - Springer Nature AN - OPUS4-55132 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Kohlbrecher, J. A1 - Breßler, Ingo T1 - SASfit 0.94.12 N2 - Small-angle scattering is an increasingly common method for characterizing particle ensembles in a wide variety of sample types and for diverse areas of application. SASfit has been one of the most comprehensive and flexible curve-fitting programs for decades, with many specialized tools for various fields. KW - Small-angle scattering KW - SAXS KW - SANS KW - Scattering pattern analysis PY - 2023 UR - https://doi.org/10.5281/zenodo.7530357 DO - https://doi.org/10.5281/zenodo.7530356 PB - Zenodo CY - Geneva AN - OPUS4-57913 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kolmangadi, Mohamed Aejaz T1 - Confinement induced relaxations and phase behavior of a nanoconfined ionic liquid crystal N2 - Liquid crystalline mesophases in nanoconfinement exhibit intriguing phase transition behaviors and relaxation dynamics. Here in, we investigate the molecular dynamics and electrical conductivity of a linear shaped guanidinium based ILC confined in self-ordered nano porous alumina oxide membranes of pore size ranging from 180nm down to 25nm by employing broadband dielectric spectroscopy (BDS) and calorimetry. Calorimetric investigation reveals a complete suppression of the columnar – isotropic transition, while the plastic crystalline – columnar transition temperature decreases with inverse pore size and deviates from the Gibbs – Thomson equation. For the bulk case, BDS detects two relaxation modes in the crystalline phase, the  relaxation and the α1 relaxation, and two relaxation modes in the columnar phase, the α2 and α3 relaxation. For the confined case, all relaxation modes slow down compared to the bulk. However, for the least pore size (25 nm), the α2 relaxation is absent. We discuss the possible molecular origins of the different relaxation modes observed. For the bulk ILC, a clear jump of 4 orders of magnitude in the absolute values of DC conductivity occurs at the transition from the plastic crystalline to hexagonal columnar phase, for the confined ILC, this transition is smooth. DC conductivity is reduced for the confined case, except for the 25nm, where the values is similar to the bulk. T2 - 11th IDS conference 2022 CY - San Sebastian, Spain DA - 03.09.2022 KW - Ionic Liquid crystals KW - Nanoconfinement KW - Conductivity PY - 2022 AN - OPUS4-55879 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Stolar, Tomislav T1 - Sustainable mechanochemical reaction engineering: from molecular mechanisms to scalable technology N2 - In this talk, I will present about our quest to fundamentally understand mechanochemical reactions by in situ monitoring studies. Another of our interest is scaling up mechanochemistry. For example, we are now working on developing mechanochemical technology to enable a circular economy of plastics. T2 - Korea-Germany Symposium on Mechanochemistry CY - Jeonju, South Korea DA - 02.10.2024 KW - Mechanochemistry KW - Plastic recycling KW - Circular economy PY - 2024 AN - OPUS4-62110 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Stolar, Tomislav T1 - Mechanochemistry: fundamentals to application N2 - In the first part, I will talk about the role of mechanochemistry in prebiotic chemistry. For example, prebiotically plausible pathways to peptides from inactivated amino acids are unclear as most oligomerization approaches rely on thermodynamically disfavored reactions in solution. I will show how a combination of mineral surfaces and mechanochemical activation enables the oligomerization of amino acids to oligopeptides (Figure 1). In the second part, I will show how fundamental studies inspired to use mechanochemistry for the sustainable synthesis of commercially relevant compounds, in line with the United Nations Sustainable Development Goals.2 We developed a solvent-free thermo-mechanochemical approach for the direct coupling of carboxylic acids and amines, which avoids activators and additives. We applied our methodology for the quantitative synthesis of the active pharmaceutical ingredient moclobemide (Figure 2). T2 - Solutions in Chemistry Conference 2024 CY - Sveti Martin na Muri, Croatia DA - 15.11.2024 KW - Mechanochemistry KW - Plastic recycling KW - Circular economy PY - 2024 AN - OPUS4-62111 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 - JOUR A1 - Kjaervik, Marit A1 - Schwibbert, Karin A1 - Dietrich, P.M. A1 - Unger, Wolfgang T1 - NAP-XPS spectra of the bacterial cell-envelope of Pseudomonas fluorescens bacteria N2 - Pseudomonas fluorescens (Gram-negative) bacteria purchased from Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures were analyzed using high-resolution x-ray photoelectron spectroscopy at near ambient pressure conditions (NAP-XPS), 1500 Pa water vapor atmosphere. Fresh layers of P. fluorescence bacteria were grown on Luria Broth agar plates. Bacteria were taken from the agar plate with a sterile spatula and gently spread on a Si-wafer piece for NAP-XPS analysis. The NAP-XPS spectra of the bacterial envelope of P. fluorescence were obtained using monochromatic Al Kα radiation and include a survey scan and high-resolution spectra of C 1s, N 1s, P 2p, and O 1s as well. The presentation of the C 1s high-resolution spectrum includes the results of peak fitting analysis. KW - Pseudomonas fluorescens KW - Cell-envelope KW - Water atmosphere KW - Near ambient x-ray photoelectron spectroscopy KW - NAP-XPS PY - 2022 DO - https://doi.org/10.1116/6.0001543 SN - 1055-5269 VL - 29 IS - 1 SP - 014008-1 PB - AVS AN - OPUS4-54464 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Richter, Anja T1 - Reducing Escherichia coli adhesion to PET by modulating spatial periods of laser-induced surface nanoripples N2 - Using nanofiber-like cell appendages, secreted proteins and sugars, bacteria can establish initial surface contact followed by irreversible adhesion and the formation of multicellular biofilms. Here, the stabilizing extracellular biofilm matrix together with physiological changes on the single cell level leads to an increased resilience towards harsh environmental conditions, antimicrobials, the host immune response and established cleaning procedures. Persistent microbial adhesion on e.g., medical implants, in water supply networks or food-processing industry is often associated with chronic inflammation, nosocomial and foodborne infections, enhanced biofouling and product contamination. To prevent persistent microbial colonization, antibacterial surface strategies often target the initial steps of biofilm formation and impede adhesion of single cells before a mature biofilm is being formed. While chemical coatings have been widely used, their restricted biocompatibility for eukaryotic cells and attenuated antibacterial-effects due to compound release limit their areas of application and alternative strategies focus on modified surfaces topographies to impede bacterial adhesion. In this work, we used ns-UV laser treatment (wavelength 248 nm and a pulse duration of 20 ns) to generate laser-induced periodic surface structures (LIPSS) with different submicrometric periods ranging from ~210 to ~610 nm on commercial poly(ethylene terephthalate) (PET) foils. Following structurally and chemically analyses, PET samples were subjected to bacterial colonization studies with Escherichia coli TG1, a bacterial test strain with a strong biofilm formation capacity due to the formation of nanofiber-like cell-appendages (pili). Bacterial adhesion tests revealed that E. coli repellence decisively depends on the spatial periods of the LIPSS with the strongest reduction (~91%) in cell adhesion observed for LIPSS periods of 214 nm. Scanning electron microscopy and additional biofilm studies using a pili-deficient E. coli TG1 strain revealed the importance of extracellular appendages in the bacterial repellence observed here, thus, pointing out new antibiotics-free strategies for antibacterial surfaces by impeding nanofiber-mediated bacterial adhesion. T2 - E-MRS Spring Meeting 2022 CY - Online meeting DA - 30.05.2022 KW - Laser-induced periodic surface structures (LIPSS) KW - Bacterial adhesion tests KW - Bacteria repellent surfaces KW - Polymer foils KW - E. coli PY - 2022 AN - OPUS4-54930 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bonse, Jörn A1 - Schwibbert, Karin T1 - Laserstrukturierte Oberflächen: Ein Weg zur Kontrolle der Biofilmbildung? N2 - Bakterielle Biofilme stellen in medizinischen und industriellen Bereichen ein ernsthaftes Problem dar. Eine der größten gesellschaftlichen Herausforderungen liegt in der zunehmenden Resistenz von Bakterien gegen Biozide, die bei antimikrobiellen Behandlungen eingesetzt werden, z.B. durch übermäßigen Einsatz in Medizin, Industrie und Landwirtschaft oder durch Reinigung und Desinfektion in Privathaushalten. Daher sind neue effiziente bakterienabweisende Strategien, die den Einsatz von Bioziden vermeiden, dringend erforderlich. Ein vielversprechender Weg zur Erzielung bakterienabweisender Oberflächen liegt in der berührungslosen und aseptischen großflächigen Laserbearbeitung von technischen Oberflächen. Maßgeschneiderte Oberflächentexturen, ermöglicht durch verschiedene Laserbearbeitungsstrategien, die zu topographischen Skalen im Bereich von Nanometern bis Mikrometern führen, können eine Lösung für diese Herausforderung darstellen. In dem Vortrag wird ein Überblick über den aktuellen Stand der Technik bei der subtraktiven Texturierung von Laseroberflächen zur Kontrolle der Biofilmbildung bei verschiedenen Bakterienstämmen und in unterschiedlichen Umgebungen gegeben. Auf der Grundlage spezifischer Eigenschaften von Bakterien und laserbearbeiteten Oberflächen werden die Herausforderungen antimikrobieller Oberflächendesigns erörtert und zukünftige Richtungen aufgezeigt. T2 - GRAVOSeminar, GRAVOmer Kompetenznetzwerk CY - Online meeting DA - 28.02.2024 KW - Laser-Materialbearbeitung KW - Ultrakurzpuls-Laser KW - Biofilme KW - Antibakterielle Oberflächen KW - Oberflächenfunktionalisierung PY - 2024 UR - https://gravomer.de/veranstaltungen-anzeigen/laserstrukturierte-oberflaechen-ein-weg-zur-kontrolle-der-biofilmbildung AN - OPUS4-59594 LA - deu 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 - CONF A1 - Quosdorf, Heike T1 - A Digital Object Identifier for Additively Manufactured Parts as Open Source Software Package N2 - A method to uniquely identify samples without printed or handwritten labels is an advantage not just for additively manufactured parts. To kickstart industry use cases it is important to provide a ready made implementation kit. Following an open science and open source software approach Germanys Federal Institute for Materials Research and Testing BAM seeks to promote digital solutions of ongoing Research projects. With this software package a novel method based on microstructural features as identifiers DOI4AM (digital object identifier for additively manufactured parts will be explained alongside its implementation as open source Python software package. The digital object identifier (DOI) links product data clearly and forgery proof with real components. Its implementation helps to identify and securely authenticate additively manufactured components during its product life cycle by using characteristic microstructure features just like a fingerprint. To calculate the DOI fingerprint, a few preprocessing steps need to be performed to detect the uniquely distributed microstructure features that occur during the 3D printing process. A go through guide show s the preprocessing steps that include computer tomography (CT) image capturing, feature segmentation and data distribution via CSV files. While all steps can be followed along in a Jupyter notebook with sample data, the software package includes functions to create and compare fingerprints, as well, as an application programming interface (API) for integration in existing software platforms. A quick showcase of our industry partners implementation of the algorithm as containerized micro service in their digital product passport (DPP) web solution PASS X proves the first successful technology transfer of this project. T2 - MSE Research Data Forum 2025 CY - Siegburg, Germany DA - 08.07.2025 KW - Open Science KW - Authentication KW - Unique identification KW - Digital fingerprint KW - X-ray Computed Tomography KW - Additive manufacturing KW - Open Source Software PY - 2025 AN - OPUS4-63904 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -