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1-Ethyl-3-methylimidazolium-bis(trifluoromethylsulfonyl)imide (EMI-TFSI) has been shown to reversibly permit lithium intercalation into standard graphite when vinylene carbonate is used in small amounts as an additive.

BackgroundThe increasing production of nanoplastics and the fragmentation of microplastics into smaller particles suggest a plausible yet unclear hazard in the natural environment, such as soil. We investigated the short-term effects (28 days) of polystyrene nanoparticles (PS-NPs) on the activity and biomass of soil microbiota, and the functional diversity of soil enzymes at environmental relevant low levels in an incubation experiment.ResultsOur results showed a significant decrease in microbial biomass in treatments of 100 and 1000 ng PS-NP g−1 DM throughout the incubation period. Dehydrogenase activity and activities of enzymes involved in N-(leucine-aminopeptidase), P-(alkaline-phosphatase), and C-(β-glucosidase and cellobiohydrolase) cycles in the soil were significantly reduced at day 28 suggesting a broad and detrimental impact of PS-NPs on soil microbiota and enzymes. Leucine-aminopeptidase and alkaline-phosphatase activities tended to decrease consistently, while β-glucosidase and cellobiohydrolase activities increased at high concentrations (e.g., PS-NP-1000) in the beginning of the incubation period, e.g., at day 1. On the other hand, basal respiration and metabolic quotient increased with increasing PS-NP application rate throughout the incubation period possibly due to increased cell death that caused substrate-induced respiration (cryptic growth).ConclusionsWe herewith demonstrated for the first time the potential antimicrobial activity of PS-NPs in soil, and this may serve as an important resource in environmental risk assessment of PS-NPs in the soil environment.Electronic supplementary materialThe online version of this article (10.1186/s12302-018-0140-6) contains supplementary material, which is available to authorized users.

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Background: Increasing exposure to engineered inorganic nanoparticles takes actually place in both terrestric and aquatic ecosystems worldwide. Although we already know harmful effects of AgNP on the soil bacterial community, information about the impact of the factors functionalization, concentration, exposure time, and soil texture on the AgNP effect expression are still rare. Hence, in this study, three soils of different grain size were exposed for up to 90 days to bare and functionalized AgNP in concentrations ranging from 0.01 to 1.00 mg/kg soil dry weight. Effects on soil microbial community were quantified by various biological parameters, including 16S rRNA gene, photometric, and fluorescence analyses.Results: Multivariate data analysis revealed significant effects of AgNP exposure for all factors and factor combinations investigated. Analysis of individual factors (silver species, concentration, exposure time, soil texture) in the unifactorial ANOVA explained the largest part of the variance compared to the error variance. In depth analysis of factor combinations revealed even better explanation of variance. For the biological parameters assessed in this study, the matching of soil texture and silver species, and the matching of soil texture and exposure time were the two most relevant factor combinations. The factor AgNP concentration contributed to a lower extent to the effect expression compared to silver species, exposure time and physico-chemical composition of soil. Conclusions:The factors functionalization, concentration, exposure time, and soil texture significantly impacted the effect expression of AgNP on the soil microbial community. Especially long-term exposure scenarios are strongly needed for the reliable environmental impact assessment of AgNP exposure in various soil types. which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.

Two novel soluble polymer-bound oligo-L-leucines 2 and 5, which can be retained by a membrane reactor system, have been prepared and used as catalysts for the continuously operated asymmetric epoxidation of chalcone. The optimized batch reaction conditions yield epoxychalcone in high enantioselectivities (up to 94%) and conversions (over 99%) after 15 minutes.Epoxides are widely used compounds in organic synthesis. 1 For this reason several approaches to effect enantioselective epoxidation have been made. 2 Among the welldeveloped methods, the Juliá-Colonna epoxidation, which utilizes chiral polyamino acids (in particular poly-L-leucine) as heterogeneous catalysts, has emerged as the first reliable method for the asymmetric epoxidation of electron-deficient olefins, exhibiting exceptionally high chiral induction for chalcone. 3Degussa and their partners from the University of Liverpool have worked intensively on the improvement of heterogeneous Juliá-Colonna oxidation. A noteworthy modification includes the introduction of percarbonate in dimethoxyethane as a cheap oxidant/solvent system for the use in some polyamino acid-catalysed epoxidations. 4The poly-L-leucine catalyst remained insoluble under all the reaction conditions applied. The first homogeneous version of the Juliá-Colonna epoxidation of trans-chalcone was reported recently. 5 However, the conversion observed was only 39% after 1 hour and 80% after 24 hours with an ee of 95-98%.Since the chiral information has to be transferred from the catalyst to the olefinic substrate, homogeneous asymmetric catalysis is a more attractive method for the synthesis of chiral epoxides. However, up to now, no process has made the step from an academically promising method to an application on larger scale.The interest of Degussa in developing methods for asymmetric synthesis in a chemzyme membrane reactor 6 promoted further investigation of the homogeneous enantioselective epoxidation of a,b-unsaturated ketones.We reasoned that the preparation of polymer enlarged oligo(L-leucine)s which were soluble in common organic solvents and large enough to be retained in a membrane reactor could allow us to develop a continuously operated asymmetric epoxidation of trans-chalcone.There are two major approaches to synthesize homogeneously soluble polymer-enlarged catalysts, that is using either linear polymers or dendrimers as carriers.We have focused our work on linear polymers, because they demand less synthetic effort. Thus, we prepared two types of soluble polymer enlarged oligo(L-leucine)s 2 and 5 (Scheme 1, Scheme 2). The approach to catalyst 2 involved the co-polycondensation of 1 equivalent of commercially available O,O-bis(2-aminoethyl)-polyethyleneglycol 20000 1 with 16 equivalents of L-leucine-N-carboxyanhydride in CHCl 3 . 7 Scheme 1 Synthesis of homogeneously soluble oligo(L-leucine) 2.We found that the resulting polyethyleneglycol-supported oligo(L-leucine) 2 can act as an efficient homogeneous chiral catalyst in the epoxidation of trans-chalcone 6 employing the urea ...

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