TY - JOUR A1 - Kellermeier, Matthias A1 - Scheck, Johanna A1 - Drechsler, Markus A1 - Rosenberg, Rose A1 - Stawski, Tomasz A1 - Fernandez-Martinez, Alejandro A1 - Gebauer, Denis A1 - Van Driessche, Alexander E. S. T1 - From Ions to Crystals: A Comprehensive View of the Non‐Classical Nucleation of Calcium Sulfate N2 - After years of intensive research and numerous important observations, our understanding of the early stages of crystallization is still limited due to the complexity of the underlying processes and their elusive character. In the present work, we provide a detailed view on the nucleation of calcium sulfate mineralization – an abundant mineral with broad use in construction industry – in aqueous systems at ambient conditions. As experimental basis, a co‐titration procedure with potentiometric, turbidimetric and conductometric detection was developed, allowing solution speciation and the formation of crystallization precursors to be monitored quantitatively as the level of nominal (super)saturation gradually increases. The nature and spatiotemporal evolution of these precursors was further elucidated by time‐resolved small‐angle X‐ray scattering (SAXS) and analytical ultracentrifugation (AUC) experiments, complemented by cryogenic transmission electron microscopy (cryo‐TEM) as a direct imaging technique. The results reveal how ions associate into nanometric primary species, which subsequently aggregate and develop anisotropic order by intrinsic structural reorganization. Our observations challenge the common understanding of fundamental notions such as the nucleation barrier or the meaning of supersaturation, with broad implications for mineralization phenomena in general and the formation of calcium sulfate in geochemical settings and industrial applications in particular. KW - Calcium sulfate KW - Gypsum KW - Nucleation KW - Crystallisation PY - 2024 DO - https://doi.org/10.1002/anie.202408429 SP - 1 EP - 12 PB - Wiley AN - OPUS4-61585 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Reigl, Selina A1 - Van Driessche, Alexander A1 - Stawski, Tomasz A1 - Koltzenburg, Sebastian A1 - Kunz, Werner A1 - Kellermeier, Matthias T1 - Sustainable Pathways for the Synthesis of Calcium Sulfate Hemihydrate N2 - Calcium sulfate, and especially its hemihydrate form (bassanite), is crucial in the construction industry, primarily used as a hydraulic binder in cements, mortars, and wallboards. Because of the rapid transformation of bassanite into thermodynamically stable gypsum (calcium sulfate dihydrate) upon contact with water, natural deposits are scarce, rendering it one of the most extensively produced inorganic materials worldwide. Currently, bassanite is derived from mined or waste gypsum through a thermal dehydration process, which is energy-intensive and costly. As sustainability has become a key target for industrial processes and products, a series of studies aiming to increase the energy efficiency and reduce the carbon footprint of bassanite production was published recently. Two primary approaches are pursued: conversion of gypsum and direct precipitation of bassanite from solution. In both cases, organic solvents, (specific) additives and/or elevated temperatures have been used to control the activity/availability of water in the reaction medium and thus direct phase selection towards bassanite. This review offers a comprehensive overview of alternative bassanite production methods, critically examining their benefits, potential downsides, and overall impact on the sustainability of industrial-scale use. KW - Calcium sulfate KW - Gypsum KW - Bassanite KW - Recycling PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-630657 DO - https://doi.org/10.1002/anie.202415161 SN - 1521-3773 SP - 1 EP - 20 PB - Wiley VHC-Verlag AN - OPUS4-63065 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Drago, Claudia T1 - Sweetening the (microplastics) pill: PET tablets (1-100µm) as candidate reference material for the validation of microplastics measurement N2 - The lack of validation and standard procedures in microplastics studies has led to the inability to compare and harmonise data from different analytical methods, laboratories and time scales. To monitor and regulate exposure to microplastics in the environment and in food for human health, it is crucial to ensure their comparability and to validate the analytical methods used in microplastics studies. Monitoring microplastics requires complex approaches for accurate determination otherwise it can lead to an over- or underestimation in environmental and food-relevant matrices. Moreover, to support the need of reliable measurement required by the European legislation directive on drinking water (EU 2020/2184) or the revision of the urban waste water directive, which will be finalised in 2024 the production and validation of polymeric reference materials with environmentally relevant concentrations, irregular shapes, defined aging status and different sizes is essential. The production of reference material with acceptable uncertainties in homogeneity need to be balanced, considering the low microplastics concentrations detected in the environment and in food. The aim of the project PLASTICTRACE and of this study, is to propose a “easy-to-use PET tablet ” (PET particle size mainly 1-100 µm) for routine applications as a candidate general reference material for detection methods. Batches of water-soluble matrix containing different concentrations of PET powder were produced. Results of imaging and counting methods (SEM, Laser diffraction), including production´s challenges; together with thermo-analytical methods (TED-GC/MS and Py-GC/MS) and vibrational spectroscopy (µ-Raman and µ-FTIR), will be presented. These data are useful to assess homogeneity and stability of the particles over time according to ISO 33405:2024. In addition, we will show some insights on the application of the PET-tablets in complex matrices, as milk powder and suspended solid from surface water, that could be easily used for routine microplastics analysis. T2 - MICRO 2024 CY - Arrecife, Spain DA - 23.09.2024 KW - Microplastics KW - Reference materials KW - Polymer 3R KW - TED-GC/MS PY - 2024 AN - OPUS4-61274 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mishmastnehi, Moslem A1 - Stawski, Tomasz M. A1 - Eftekhari, Negar A1 - Schneider, Kathrin P. A1 - Vaccaro, Carmela A1 - Aghajani, Iman A1 - Grbanovic, Ana Marija A1 - Korn, Lorenz T1 - Unveiling the craftsmanship and knowledge behind iranian stuccoes (11th–14th centuries): New insights from an archaeometric perspective N2 - Gypsum-based stucco decorations of 47 monuments in Iran, from the Seljuq to the Ilkhanid period (11th-14th centuries), were studied by multimodal analytical methods, including X-ray diffraction, X-ray fluorescence, scanning electron microscopy and image analysis to evaluate their composition properties. The assessment of results shows that stucco masters in those periods exerted control over the setting process of the gypsum-paste and its microstructure by adjusting water-to-plaster ratio, fine-clay addition, and by means of mechanical processing. Furthermore, the presence of anhydrite in the composition of stucco decorations located in the hot-desert climate of Iran provides evidence for the probability of gypsum-anhydrite transition, which has technical and preservation consequences for this less-investigated type of cultural materials. KW - Gypsum KW - Diffraction KW - Anhydrite KW - Calcium sulfate PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-628406 DO - https://doi.org/10.1016/j.jas.2025.106199 SN - 1095-9238 VL - 177 SP - 1 EP - 13 PB - Elsevier B.V. AN - OPUS4-62840 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 - CONF A1 - Ryll, Tom William T1 - Applied and Technical Mineralogy:� high-throughput automated platform for in-situ monitoring of CaSO4 formation N2 - In this project we investigate nucleation pathways by utilizing synchrotron-XRD and running a case-study on calcium sulfate and its polymorphs. To accomplish this, we developed a modular automation setup for reactions in solution to run synthesis and control reaction conditions. So far we successfully characterized the recycling process of gypsum (CaSO4*2H2O) and are now investigating the formation of anhydrite (CaSO4*0H2O) as well as possible applications for the automation setup and analysis. T2 - Geo4Göttingen 2025 CY - Göttingen, Germany DA - 14.09.2025 KW - Recycling KW - Gypsum KW - Synchrotron-X-ray-diffraction KW - Raman-spectroscopy KW - Automation PY - 2025 AN - OPUS4-64139 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Stolar, Tomislav T1 - Thermo mechanochemistry: merging heat and force for discovering new chemical transformations N2 - Mechanochemistry is a hot topic in chemistry, and the number of researchers from academia and industry joining the field is growing. Mechanical action drives chemical reactions forward independently of the solubility of reactants and drastically minimises solvent usage and waste production. Mechanochemistry also provides other advantages, such as faster reaction times, higher yields, altered selectivity, and access to products not obtainable by other methods. Furthermore, recent innovations in mechanochemistry enable conducting chemical reactions by combining force and heat in approach called thermo-mechanochemistry [1]. These conditions typically overcome high activation energies and access products not obtainable by mechanochemistry at ambient temperature conditions. In this talk, I will give an overview to this emerging topic and to our discoveries by thermo-mechanochemistry that include prebiotic peptide bond formation [2], synthesis of amide-based active pharmaceutical ingredient [3], condensation of diamondoid derivatives [4], and manipulation of polymorphic transition temperatures in organic molecular crystals [5]. T2 - Department Seminar at Newcastle University CY - Newcastle, UK DA - 15.09.2023 KW - Mechanochemistry PY - 2023 AN - OPUS4-62104 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 - Hokkaido International Workshop on Mechanochemistry CY - Hokkaido, Japan DA - 29.09.2024 KW - Mechanochemistry KW - Plastic recycling KW - Circular economy PY - 2024 AN - OPUS4-62109 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Stolar, Tomislav T1 - Grinding away plastic waste: enabling the circular economy of plastics N2 - Single-use plastics are causing plastic pollution, and less than 10% of plastic waste gets recycled globally. Most of it ends up in landfills or is being incinerated in a highly unsustainable manner. Plastic waste in the environment endangers ecosystems, and microplastics in babies raise alarming health concerns. Hence, one of the global priorities is circular economy for plastics which does not further exploit fossil fuel feedstocks. However, current technologies like mechanical recycling are inadequate, and innovative ones such as chemical recycling, i.e., converting plastics back to the starting monomers, are essential. For example, we can use the recycled monomers to make new plastics in a circular manner or upcycle them to other value-added functional materials. Here, I will present a sustainable technology we developed for the chemical recycling of polyethylene terephthalate (PET). PET represents 10% of global plastic production and dominates in plastic packaging. The technology relies on mechanochemistry (grinding) which uses mechanical action for the chemical breakdown of plastic polymers in an environmentally friendly way. The next step in our research is to use life cycle and techno-economic assessment to validate the sustainability and commercial viability of our technology with the goal of transferring it to real-world industrial application. T2 - Berlin PostDoc Day 2023 CY - Berlin, Germany DA - 02.11.2023 KW - Mechanochemistry KW - Plastic recycling KW - Circular economy PY - 2023 AN - OPUS4-62103 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -