A novel silsesquioxanes modified electrospun composite fibrous separator by in-situ crosslinking method for lithium-ion batteries

Microporous electrospun PVDF-HFP nonwoven separators have advantages of higher porosities and better wettabilities compared with conventional polyolefin, but suffer from low mechanical strength and excessive swelling in electrolyte. To enhance the mechanical properties, thermal and dimensional stabilities as well as electrochemical performance of electrospun separators, cross-linked membranes covalently integrated with hybrid silsesquioxane components were fabricated by in-situ crosslinking method, obtaining armor-like shell structure coated on PVDF-HFP fibers. The silsesquioxanes crosslinked PVDF-HFP fibers separator (SQ-PFF) exhibits excellent tensile and puncture strength, superior thermal and dimensional stabilities. Besides, the SQ-PFF prepared cells revealed remarkable discharge capacity and excellent cycling performance ascribing to the high lithium-ion conductivity and the enhanced cross-linked structure. (C) 2019 Elsevier B.V. All rights reserved

Silsesquioxane-Polythiophene Hybrid Copolymer as an Efficient Modifier for Single-Walled Carbon Nanotubes

One silsesquioxane-polythiophene hybrid copolymer, with combined star-like structure and intramolecular heterogeneity, was synthesized and sufficiently characterized via various methods, including FTIR, NMR, and SEC measurements. According to the exploration and characterization results, it was much more efficient at modifying SWNTs than its linear analogs in aqueous solution. The hydrophobic silsesquioxane core and PEDOT chains could locally anchor to the surface of the nanotubes, while the soluble flexible copolymer chains extended into the solution and rigid conjugated chains provided some π-π stacking effect to enhance adhesive force with the conjugated structure of the carbon nanotube, imparting steric stabilization to nanotube dispersion. The noncovalent interaction with SWNTs and solubility in aqueous solution improved the electrochemical characteristics of the modified-SWNT composite and availed for the preparation of a flexible and transparent electroactive film. Accordingly, this kind of silsesquioxane-polythiophene hybrid copolymer will be forwarded to apply to the assembling of flexible optoelectronic devices

A soluble star-shaped silsesquioxane-cored polymer-towards novel stabilization of pH-dependent high internal phase emulsions

A well-defined pH-responsive star-shaped polymer containing poly(N, N-dimethylaminoethyl methacrylate) (PDMA) arms and a cage-like methacryloxypropyl silsesquioxane (CMSQ-T-10) core was used as an interfacial stabilizer for emulsions consisting of m-xylene and water. We explored the properties of the CMSQ/PDMA star-shaped polymer using the characteristic results of nuclear magnetic resonance (NMR) spectroscopy, size exclusion chromatography (SEC), dynamic light scattering (DLS), and zeta potential and conductivity measurements. The interfacial tension results showed that the CMSQ/PDMA star-shaped polymer reduced the interfacial tension between water and oil in a pH-dependent manner. Gelled high internal phase emulsions (HIPEs) including o/w and w/o types were formed in the pH ranges of 1.2-5.8 and 9.1-12.3 with the CMSQ/PDMA star-shaped polymer as a stabilizer, when the oil fractions were 80-90 vol% and 10-20 vol%, respectively. The soluble star-shaped polymer aggregated spontaneously to form a microgel that adsorbed to the two immiscible phases. Images of the fluorescently labeled polymers demonstrated that there was a star-shaped polymer in the continuous phase, and the non-Pickering stabilization based on the percolating network of the star-shaped polymer also contributed to the stabilization of the HIPE. This pH-dependent HIPE was prepared with a novel stabilization mechanism consisting of microgel adsorption and non-Pickering stabilization. Moreover, the preparation of HIPEs provided the possibility of their application in porous materials and responsive materials