TY - CONF A1 - Piedade, M. F. M. T1 - Crystal Engineering through Solvent Mediated Control of Molecular Conformation: The Case of 5-Hydroxynicotinic Acid N2 - The importance of molecular conformation for polymorphism and its repercussions in terms of tight control over the industrial production of crystalline organic materials with highly reproducible physicochemical properties has long been recognized. Efforts to understand how a crystallization solvent can direct the formation of a polymorph containing a specific molecular conformation are, however, relatively scarce. Nicotinic acid (NA) and its hydroxyl derivatives (2-, 4-, 5-, and 6-hydroxynicotinic acids) are very good models for such studies. Indeed, regardless of the solvent, NA always crystallizes as a single polymorph with the molecule in the same neutral conformation. In contrast, the hydroxyl derivatives are prone to polymorphism and solvate formation and, depending on the crystallization conditions, the molecules in the crystal lattice can exhibit hydroxyl, oxo, or zwitterionic conformations. The present study focused on 5-hydroxynicotinicacid (5HNA) shows that by judicious selection of the solvent it is possible to obtain 1:1 solvates, where solvation memory is not completely lost and the tautomer preferred in solution persists in the crystalline state: zwitterionic in 5HNA·H2O and neutral in 5HNA·DMSO. Nevertheless, upon thermal desolvation the obtained materials evolve to the same unsolvated form where the molecule is in a zwitterionic conformation. The structures of 5HNA·H2O and 5HNA·DMSO obtained from single crystal-ray diffraction are discussed and compared with that of 5HNA solved from powder data. The energetics of the dehydration/desolvation process was also fully characterized by thermogravimetry (TG), differential scanning calorimetry (DSC) and Calvet microcalorimetry. T2 - BACG 2018 CY - Limerick, Ireland DA - 20.06.2018 KW - Crystal Engineering KW - 5-hydroxynicotinic acid KW - Molecular Conformation PY - 2018 AN - OPUS4-45519 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Manoharan, Deepak A1 - Ranjan, Subham A1 - Emmerling, Franziska A1 - Bhattacharya, Biswajit A1 - Takamizawa, Satoshi A1 - Ghosh, Soumyajit T1 - Elasto-plastic behaviour with reversible thermosalient expansion in acrylonitrile-based organic crystals N2 - Crystalline materials that exhibit reversible mechanical responses upon exposure to external stimuli have garnered significant attention owing to their potential applications in various fields. Herein, we report a crystal of (2Z,2′Z)-2,2′-(1,4-phenylene)bis(3-(4-bromophenyl)acrylonitrile) (DSBr), which displays simultaneous elasto-plastic behaviour and reversible thermosalient effects. While elasto-plastic behaviour is attributed to underlying packing features, reversible thermosalient expansion is attributed to uniaxial expansion mediated by heat. Exceptional length increase and contraction upon cooling is due to the restorative nature of weak interactions through a cooperative effect. The cooperative movement of molecules is reflected in the unidirectional expansion of the habit plane. Thermosalient reversible expansion–contraction in elasto-plastic crystals have not been discussed in the literature so far. Detailed analysis reported herein provides a comprehensive understanding of the underlying mechanism of flexibility and thermosalient responses. This crystal's unique blend of reversible thermal expansion with flexibility holds substantial promise for applications in flexible thermal actuators. KW - Materials Chemistry KW - General Chemistry PY - 2024 DO - https://doi.org/10.1039/D3TC04272C SN - 2050-7526 SP - 1 EP - 11 PB - Royal Society of Chemistry (RSC) AN - OPUS4-59527 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Altmann, Korinna T1 - Validation of microplastics detection methods and proficiency testing: Suitable microplastic reference materials for interlaboratory comparison N2 - The talk summarizes challenges in microplastic analysis. It shows the preparation of microplastic reference materials as well as the testing on homogeneity and stability. The reference material is used in an international laboratory comparison to compare different detection methods used for microplastic analysis. The methods used were µ-IR (FTIR+LDIR) for number-based methods and TED-GC/MS and Py-GC/MS for mass-based methods. The ILC was done under the umbrella of VAMAS TWA 45. Results of the participants are presented. T2 - BAM Akademie CY - Online meeting DA - 16.05.2024 KW - Microplastics KW - Reference materials KW - ILC KW - Microplastics detection KW - TED-GC/MS KW - Polymer 3R PY - 2024 AN - OPUS4-60085 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Giovannozzi, A T1 - Metrological traceability of measurement data from nano- to small microplastics for a greener environment and food safety N2 - This talk descibes the EMPIR project PlasticTrace. Reference materials for microplastics will be developed. The production process and characterisation is explained by SEM, Raman, IR, Py-GC/MS and TED-GC/MS. Homogeneity control was successful. Stability check show no changes over 6 month. T2 - SETAC Europe 2024 CY - Sevilla, Spain DA - 05.05.2024 KW - Microplastics KW - Reference materials KW - Polymer 3R KW - TED-GC/MS PY - 2024 AN - OPUS4-60033 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radnik, Jörg T1 - Revealing surface functionalities of micro- and nanoplastic particles’ surface by means of XPS N2 - Over the last 20 years, many researchers, politicians, and citizens themselves have become increasingly aware of the growing plastic problem of our time. Inadequate recycling concepts, collection points, and careless dumping of plastic products in the environment lead to an accumulation of plastic. External weather influences can cause these to degrade and fractionate, so that today microplastics (1-1000 µm, ISO/TR 21960:2020) [1] of different polymer materials can be detected in all parts of the world. The precautionary principle applies to microplastics. The particles can break down further to form nanoplastics (<1 µm, ISO/TR 21960:2020) [1]. Whether microplastics or nanoplastics pose a toxicological hazard is being investigated in a variety of ways. Valid results are still pending, however, investigations into the frequency, transport, possible sinks and entry paths must be taken into account. This is why monitoring of microplastics is already required in the revision of the Drinking Water Framework Directive [2]. The same is still pending in the final version of the revision of the Waste Water Framework Directive this year, but is expected. Nanoplastics are particularly under discussion for having a toxic effect on humans and animals, as these particles are small enough to be absorbed by cells. For targeted toxicological studies, it is important to have test and reference materials that resemble the particles found in the environment. To mimic environmental samples, these materials should also have an irregular shape and show aging at the surface, which can be detected with XPS or SEM/EDS. BAM in collaboration with the EMPIR project "PlasticTrace" works on a reference material candidate of nano-sized polypropylene (nano-PP) [3]. The nano-PP vials were tested for homogeneity with PTA and further characterized with bulk and surface-sensitive techniques. An SEM image and a corresponding XPS spectrum are presented in Figure 1. Raman measurements as well as XPS indicate an aged surface. T2 - ECASIA 2024 CY - Gothenburg, Sweden DA - 09.06.2024 KW - Surface chemistry KW - Micro- and nanoplastics KW - X-ray Photoelectron Spectroscopy KW - MNP production technique PY - 2024 AN - OPUS4-60535 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ciornii, Dmitri T1 - Interlaboratory comparisons for obtaining reliable data on microplastic detection methods N2 - Since microplastics (MPs) can be found everywhere and are becoming a problem of high concern, it is necessary to understand their occurrence and fate in the environment. However, to obtain data of high quality is very challenging, since measurement operating procedures differ from laboratory to laboratory. Currently, there are no standardized methods to analyze microplastics. One promissing possibility to adress standardization of the methodology and operating procedures are interlaboratory comparisons (ILCs). In this contribution we report the first results of an ILC on microplastic detection methods organized under the pre-stantdardisation plattform of VAMAS (www.vamas.org/twa45/) as Project 2 “Development of standardized methodologies for characterisation of microplastics with microscopy and spectroscopy methods”, within the Technical Working Area TWA 45 “Micro and Nano Plastics in the Environment”. The ILC has gathered 84 participants all over the world representing all continents. BAM, as the project leader, produced a set of reference microplastic materials, which have been distributed to all the participants together with the measurement protocols and reporting data templates. T2 - SETAC 34th Meeting CY - Seville, Spain DA - 05.05.2024 KW - ILC KW - Microplastic KW - Py-GC/MS KW - Polyethylene KW - µ-Raman KW - µ-FTIR KW - Polyethylene Terephtalate KW - TED-GC/MS PY - 2024 AN - OPUS4-60038 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Drago, C. T1 - Standardization Methods for the Analysis of Microplastics (10 100µm) in Food Matrix: Sample Preparation and Digestion of Milk Powder. N2 - Monitoring of microplastics in food matrices is crucial to determinate the human exposure. By direct ingestion microplastics could be released in the food during the production, through packaging and by consumer’s use. The absence of standard methods to quantify and detect different size range and type of microplastics has led to difficult and time consuming procedural steps, poor accuracy and lack of comparability. In this work, matrix characterization and laboratory experiments were used to investigate the efficiency of sample preparation in milk powder. This information is crucial to compile a standard procedure for sample preparation and digestion of common milk powder to detect different particle sizes and types of polymers. Charaterisation is done by TGA and TOC measurements. T2 - SETAC Europe 2024 CY - Sevilla, Spain DA - 05.05.2024 KW - Microplastics KW - Harmonisation in microplastics KW - Polymer 3R KW - Microplastics in milk PY - 2024 AN - OPUS4-60034 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Heinekamp, Christian T1 - An Amorphous Lewis-acidic Zirconium Chlorofluoride as HF Shuttle: C-F Bond Activation and Formation N2 - In recent years, fluorine chemistry has gained increasing political attention. Owing to a growing shortage of fluorspar, a raw material used for producing fluorinated base chemicals, fluorospar has been named among the 30 critical raw materials in the EU.2 As such, it becomes increasingly important to recycle existing fluorinated compounds and make them available as sources of fluorine for reactions. Significant progress has been made in the field of C-F bond activation using heterogeneous catalysts such as aluminum chlorofluoride (ACF).3–5 However, the transfer of fluorine atoms from one molecule to another using heterogeneous catalysts has not yet been reported. In this study, we successfully synthesized amorphous zirconium chlorofluoride (ZCF), and we were able to establish a catalytic behavior of ZCF in C-F bond activation reactions. We present a heterogeneous catalyst that performs dehydrofluorination of a fluoroalkane and consecutive hydrofluorination of an alkyne at room temperature. T2 - 2nd South African Fluorine Symposium CY - Sun City, South Africa DA - 09.02.2024 KW - ZCF KW - Heterogeneous catalysis KW - C-F bond activation KW - HF-shuttle PY - 2024 AN - OPUS4-59618 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Heinekamp, Christian T1 - A fluorolytic sol-gel route to access an amorphous Lewis-acidic Zr fluoride catalyst N2 - Kemnitz et al. developed a fluorolytic route to access metal fluorides 2 such as AlF3 3 and MgF2 4 which possess a high surface area. In aluminium-based systems, the synthetic approach led to amorphous xerogels that can be further converted into Lewis superacids.3 Still, despite zirconium oxide being described as a stronger Lewis acid than other metal oxides 4 zirconium fluoride-based materials have only recently been reported or investigated. 6 In this work we extend the class of amorphous Lewis acidic heterogeneous catalysts to an amorphous ZrF4 that is active in C-F bond activation. T2 - 2nd South African Fluorine Symposium CY - Sun City, South Africa DA - 11.02.2024 KW - ZrF4 KW - Heterogeneous catalysis KW - C-F bond activation PY - 2024 AN - OPUS4-59617 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - George, Janine T1 - Openness, Curiosity and Identity N2 - I am introducing early-career researchers to my view on the academic career. I highlighted openness with regard to people. I mentioned my interest in multiple fields of the natural sciences, driving my curiosity. I additionally highlight my core belief that science is a team sport. T2 - Open Minds – Exploring Science Careers CY - Berlin, Germany DA - 05.03.2026 KW - Materials Informatics PY - 2026 AN - OPUS4-65632 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -