Open Access

A sustainable mechanochemical process for the generation of sodium aluminium fluorides by conversion of polyvinylidene fluoride (PVDF) waste on using ball milling in the presence of a Lewis acid was developed. The generated fluorides can be key materials for the aluminium production process. The Lewis acid AlCl3 initiates dehydrofluorination steps at PVDF, releasing HF for further fluorination of both NaCl and AlCl3 to yield chiolite under ball milling conditions. Further calcination of chiolite generates cryolite with an overall yield of 62% with respect to AlCl3. The procedure avoids the use of solvents and minimises energy consumption. The identity and phase purity of the products was confirmed by XRD, NMR, IR, and Raman analyses. It was also demonstrated that powdered PVDF, real-life PVDF membrane waste orPVDFextracted from Li-ion batteries can be upcycled into industrially relevant fluoride materials. The presented method offers a sustainable approach for resource recovery and environmental remediation.

Size Exclusion Chromatography (SEC) remains the most widely applied technique for determining molar mass averages and molar mass distributions of polymers. By separating molecules according to their hydrodynamic volume using a porous stationary phase, SEC provides a chromatogram that, when calibrated with standards of known molar mass, yields a relative molar mass distribution curve. From this curve, key parameters such as number-average molar mass (Mn), weight-average molar mass (Mw), and oligomer content—defined as fractions below 1000 g/mol and 500 g/mol—can be derived. These low-mass fractions are of particular regulatory interest because they represent mobile species with potentially higher bioavailability and toxicity. However, SEC is not without limitations. While error margins of 10–20% for molar mass determination across laboratories and instruments are well documented, variability in oligomer quantification may be even greater. Influencing factors include solvent choice, column configuration, dissolution behaviour, and baseline integration settings. Current DIN and ISO standards, developed from earlier interlaboratory studies, do not adequately address these challenges, especially under conditions relevant to real-life polymer samples. To quantify these uncertainties, a comprehensive round robin test was conducted between June 2024 and February 2025 with 35 laboratories worldwide. Unlike previous studies focused on narrowly dispersed standards, this initiative included complex real-world samples such as copolymers, blends, and dispersions with gel content as a material exhibiting partial solubility. Analyses were performed in three solvent systems (THF, DMAc/DMF, and water) to reflect diverse application scenarios. The results reveal significant interlaboratory variation, particularly in the low molar mass region, with deviations exceeding 50% for Mn and even higher for oligomer content in challenging matrices. These findings underscore the urgent need for harmonized protocols, improved calibration strategies, and clear guidance on solubility and sample preparation. This contribution presents results of the round robin study. Example cases will be discussed and interpreted to allow recommendations for method harmonization. Reducing variability in SEC polymer characterization and increasing the comparability of results are critical steps toward reliable data for regulatory compliance and polymer safety assessment.

Polymers are ubiquitous materials found in various products, including clothing, cosmetics, wall paints, and medical devices. With estimates ranging from 70,000 to 400,000 commercially available polymers in the EU, the need for effective regulation is paramount. Despite their extensive use, polymers have often been exempted from regulations like REACH, leading to a significant data gap regarding their environmental hazards and risks. In contrast to small molecules, polymers are characterized by a heterogeneity in their molecular and chemical properties. This means they show distributions in their properties (e.g. in molar mass) instead of a single value. Consequently, different descriptors are needed for a meaningful safety assessment and existing analytical methods and guidelines often fail for polymers. Small molecules, like monomers, additives and stabilizers in polymers behave significantly different than oligomers. Polymers as molecules or in solution are again different to polymer particles, namely microplastics. We will dive into the fundamentals of analytical methods, from separation techniques to phys-chem properties, used to characterize and describe polymers, so we understand their value as well as their problems and challenges. The course will also provide some regulatory context how oligomers and polymers are currently handled under the REACH Regulation and how this might change in the future.

This work addresses a key challenge in scaling up mechanochemical synthesis: deriving a kinetic model when unpredictable formation and intricate interaction of multiple crystalline phases occur during solid state transformations. Reaction kinetics translate our understanding of chemical processes into mathematical rate expressions used for reactor design and evaluation, thus representing a challenge to be addressed for the scale up at the industrial level. Choosing co-crystallization of chloro-3 sulfamoylbenzoic acid (CSBA) and isonicotinamide (INA) as a model system, at first we employ time resolved in situ powder X-ray diffraction (PXRD) and multivariate curve resolution-Alternating Least Squares (MCR-ALS) analysis to quantify and resolve the evolution of crystalline intermediates under varying methanol-assisted conditions. Our data show that even small changes in the amount of methanol can dramatically alter the kinetic profile, stabilise transient phases (including some that were previously unreported) and alter the overall reaction pathway. We then demonstrate the robust deconvolution of overlapping phases and the extraction of quantitative rate parameters that rationalize the observed behaviour by integrating kinetic modelling as a soft-hard constraint in the MCR-ALS workflow. The validation of the established MCR-ALS workflow is achieved by applying a phenomenological kinetic modelling tailored to rationalize the mechanochemical reaction rates. These results establish a broadly applicable platform for analysing and controlling the complex phase evolution, along with the derivation of a kinetic model instrumental to mechanochemical process development and scaling up, thereby supporting the transition of sustainable solid-state syntheses from the laboratory to industry.

The next generation of materials, including climate-neutral energy systems, resilient infrastructures, the circular use of resources and digital product passports, demands an end to the siloing of synthesis, characterisation and data. Rather than pursuing increasingly specialised single measurements, we require experimental ecosystems that connect length scales, modalities and environments closely enough to track materials from their inception in the laboratory to their failure in real-world applications. In such a landscape, multimodality is not just a buzzword; it is a prerequisite for asking the right questions and judging which data we really need. Truly multimodal approaches present us with practical and conceptual challenges. The experiments need to remain feasible within limited beam time while combining several probes and realistic operando environments. We also need strategies to make heterogeneous data interoperable, traceable, and reusable across instruments, projects, and regulatory contexts. Furthermore, we must ensure that the increasing complexity of setups and workflows leads to clear, decision-ready insights rather than merely larger datasets. In this contribution, I will outline how we address these challenges at BAM by linking multimodal synchrotron methods with unconventional syntheses, such as mechanochemistry, and with complementary laboratory infrastructures. We also embed these methods in data-driven, partially automated workflows that connect