Investigation on the Copolymer Electrolyte of Poly(1,3-dioxolane-co-formaldehyde).

A series of copolymers are prepared via cationic ring-opening polymerization with 1,3-dioxolane (DOL) and trioxymethylene (TOM) as monomers. The crystallization behaviors of the copolymers can be suppressed by adjusting the ratio of DOL/TOM. With LiBF4 as a source for a BF3 initiator, copolymer electrolytes (CPEs) can be prepared in situ inside cells without needing nonelectrolyte catalysts or initiators. The ionic conductivities and Li+ diffusion coefficients ( D Li + ) of the CPEs increase with a decreasing DOL/TOM ratio in a certain range. The CPE with a DOL/TOM ratio of 8/2 has the highest ionic conductivity as well as D Li + and shows excellent interfacial compatibility with lithium (Li) metal anodes. Li-Li symmetric cells can be uniformly plated/stripped for more than 1200 h. Furthermore, LiFePO4 -Li cells with 8/2-CPE display stable cycling performance for over 400 cycles. This strategy is a promising approach for the preparation of high-performance polymer electrolytes and is sure to promote their application in Li metal batteries.

Efficient direct preparation of antifungal Alteramide B from Lysobacter enzymogenes fermentation broth by macroporous resin adsorption.

Alteramide B (ATB) is an antifungal metabolite produced by Lysobacter enzymogenes. However, its separation method has not been explored. This study attempted to directly adsorb ATB from fermentation broth using macroporous adsorption resins (MARs) NKA resin exhibited better adsorption as well as desorption capacities. The static and dynamic adsorption characteristics were assessed to determine the following optimal separation conditions: initial fermentation broth with a pH of 12.0, 2 BV/h flow rate, 8 BV loading volume, and 6 BV 80% aqueous ethanol for elution. After a single treatment, ATB content in the final product was higher by 4.51-fold (i.e, from 12.72 ± 1.21% to 57.35 ± 3.46%), resulting in a recovery yield of 86.20 ± 4.47%. In addition, NKA resin showed superior reusability within eight cycles of adsorption/desorption. The developed method is thus a simple, efficient, and economical process for ATB separation.

A bare-eye based one-step signal amplified semiquantitative immunochromatographic assay for the detection of imidacloprid in Chinese cabbage samples.

A novel bare-eye based one-step signal amplified semi-quantitative immunochromatographic assay (SAS-ICA) was developed for detection of the pesticide imidacloprid. This method was based on competitive immunoreactions. Signal amplification was achieved by dual labeling of the test lines (TLs) on the strip using high affinity nanogold-biotinylated anti-imidacloprid mAb (BAb) and nanogold-streptavidin (Sa) probes. The relative color intensities of three TLs (TL-I, TL-II and TL-III) on a nitrocellulose (NC) membrane were used for direct visual analysis of the SAS-ICA strips, and could be used for semi-quantitation of analyte concentrations by observing what TLs disappeared in the amplification zone. Under optimized conditions, the following imidacloprid concentration ranges would be detected by visual examination of the SAS-ICA strip: 0-5ngmL(-1) (negative samples), and 5-25ngmL(-1), 25-250ngmL(-1), 250-1000ngmL(-1) and >1000ngmL(-1) (positive samples). The sensitivity (the visual detection limit (VDL) of TL-III) and semi-quantitative analytical capacity (when TL-III disappeared completely) of the SAS-ICA strip were 10-fold and 160-fold higher than those of traditional ICA, respectively. The developed SAS-ICA strip was applied to the analysis of spiked and authentic contaminated Chinese cabbage samples in the laboratory and under field conditions, and the results were validated by high-performance liquid chromatography (HPLC). This process could be adopted as a potential generous technique for all ICA-based detection methods.