Porous Salts Containing Cationic Al24 -Hydroxide-Acetate Clusters from Scalable, Green and Aqueous Synthesis Routes.

The solution chemistry of aluminum is highly complex and various polyoxocations are known. Here we report on the facile synthesis of a cationic Al24 cluster that forms porous salts of composition [Al24 (OH)56 (CH3 COO)12 ]X4 , denoted CAU-55-X, with X=Cl- , Br- , I- , HSO4 - . Three-dimensional electron diffraction was employed to determine the crystal structures. Various robust and mild synthesis routes for the chloride salt [Al24 (OH)56 (CH3 COO)12 ]Cl4 in water were established resulting in high yields (>95 %, 215 g per batch) within minutes. Specific surface areas and H2 O capacities with maximum values of up to 930 m2 g-1 and 430 mg g-1 are observed. The particle size of CAU-55-X can be tuned between 140 nm and 1250 nm, permitting its synthesis as stable dispersions or as highly crystalline powders. The positive surface charge of the particles, allow fast and effective adsorption of anionic dye molecules and adsorption of poly- and perfluoroalkyl substances (PFAS).

Portable Hyperpolarized Xe-129 Apparatus with Long-Time Stable Polarization Mediated by Adaptable Rb Vapor Density.

The extraordinary sensitivity of 129Xe, hyperpolarized by spin-exchange optical pumping, is essential for magnetic resonance imaging and spectroscopy in life and materials sciences. However, fluctuations of the polarization over time still limit the reproducibility and quantification with which the interconnectivity of pore spaces can be analyzed. Here, we present a polarizer that not only produces a continuous stream of hyperpolarized 129Xe but also maintains stable polarization levels on the order of hours, independent of gas flow rates. The polarizer features excellent magnetization production rates of about 70 mL/h and 129Xe polarization values on the order of 40% at moderate system pressures. Key design features include a vertically oriented, large-capacity two-bodied pumping cell and a separate Rb presaturation chamber having its own temperature control, independent of the main pumping cell oven. The separate presaturation chamber allows for precise control of the Rb vapor density by restricting the Rb load and varying the temperature. The polarizer is both compact and transportable─making it easily storable─and adaptable for use in various sample environments. Time-evolved two-dimensional (2D) exchange spectra of 129Xe absorbed in the microporous metal-organic framework CAU-1-AmMe are presented to highlight the quantitative nature of the device.

In-depth characterization revealed polymer type and chemical content specific effects of microplastic on Dreissena bugensis.

In aquatic ecosystems, filter feeders like mussels are particularly vulnerable to microplastics (MP). However, little is known about how the polymer type and the associated properties (like additives or remaining monomers) of MP impact organisms, as the predominant type of MP used for effect studies on the organismic level are micron grade polystyrene spheres, without considering their chemical composition. Therefore, we exposed the freshwater mussel Dreissena bugensis (D. bugensis) to in-depth characterized fragments in the same concentration and size range (20-120 µm): recycled polyethylene terephthalate from drinking bottles, polyamide, polystyrene, polylactic acid, and mussel shell fragments as natural particle control. Real-time valvometry, used to study behavioral responses via the movement of the mussels' valves, showed that mussels cannot distinguish between natural and MP particles, and therefore do not cease their filtration, as when exposed to dissolved pollutants. This unintentional ingestion led to polymer type-dependent adverse effects (activity of antioxidant enzymes and proteomic alterations), related to chemicals and residual monomers found in MP. Overall, recycled PET elicited the strongest negative effects, likely caused by anthranilamide, anthranilonitrile and butylated hydroxytoluene, contained in the fragments, which are toxic to aquatic organisms. As PET is among the most abundant MP in the environment, sublethal effects may gradually manifest at the population level, leading to irreversible ecosystem changes.