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A recent article in Angewandte Chemie International Edition discusses the synthesis and use of a fluorine-free, dumbbell-shaped block-graft copolymer as a hydrocarbon polymer electrolyte membrane for fuel cells. The unique structure of the polymer chains resulted in the alignment of phase-separated domains and the creation of continuous proton channels throughout the membrane. This allowed for efficient proton transport and ensured stable performance. The authors suggest that this novel polymer structure shows promise for hydrocarbon PEMs as alternatives to PFSAs. [Extracted from the article]

A recent article in Angewandte Chemie discusses the synthesis of a fluorine-free, dumbbell-shaped block-graft copolymer that can be used as a hydrocarbon polymer electrolyte membrane for fuel cells. The unique structure of the polymer chains allows for the alignment of phase-separated domains and the creation of continuous proton channels throughout the membrane. This enables efficient proton transport and ensures stable performance. The authors suggest that this novel polymer structure shows promise as an alternative to perfluorosulfonic acid membranes. [Extracted from the article]

We report the formation of a reversible complex between CO2 and a bound water coordinating alkaline metal cation (Lewis-acidic water) by nuclear magnetic resonance (NMR) analysis for the first time. Such a unique property of water can facilitate CO2 permeation by offering an additional carrier-mediated pathway, which is distinct from the commonly recognized bicarbonate or carbonate ion-mediated CO2 transport. These findings were exploited to develop an advanced polymeric membrane for separating CO2 directly from wet flue gases. A simply prepared poly(ethylene oxide)-based membrane containing potassium salts exhibits selective super-permeable characteristics for CO2 in humid environments; an exceptionally high CO2 permeance of 4650 gas-permeation units (GPU) with an ideal separation factor of 1500 was achieved for CO2/N2, which lies far above the upper bound of the selectivity–permeability trade-off curve, without any significant performance degradation over 6 months. [ABSTRACT FROM AUTHOR]

Nanocomposites of ionic liquid, 1-butyl-3-methylimidazolium tetrafluoroborate (BmimBF4), in three-dimensional mesoporous silica (KIT-6) were fabricated and utilized as mesopore-confined ionic liquid membranes for Olefin and CO2 Separation. Compared to neat BmimBF4, the fabricated membrane showed 10-times-enhanced gas permeation property for olefin separation, and 5-times-enhanced gas permeation property for CO2 separation with gas-selectivity remaining unchanged. Moreover, the enhanced diffusion-limited current density of the electrochemical cell involving I-/I3- redox couple in BmimBF4/KIT-6 nanocomposite was observed. This implies that mesoporous KIT-6 can be used as an effective additive in nanocomposite membranes for enhanced olefin and CO2 permeance. [ABSTRACT FROM AUTHOR]

Abstract: In this study, we report the enhanced carrier activity of potassium cation (K+) not only with fluoride but also fluorosilicate anions, prepared by the simple heat-treatment of polymer electrolyte solution in glass vial. The formation of water-soluble fluorosilicate anions such as SiF5(H2O)– was investigated by 19F NMR spectroscopy and thermogravimetric analysis (TGA). The XPS data revealed the increased binding energy of K2p3/2 up to 294.6eV with broad spectrum for F1s binding energy. The interaction between K+ and the amide groups of PVP was confirmed by FT-IR spectroscopy. As a result, membranes containing K+ demonstrated a selectivity ratio CO2/N2 and CO2/CH4 of 25.62 and 25.87, respectively, with a CO2 permeance of 52.01GPU. This enhanced separation performance was mostly attributable to the counter-anion effect on K+ carrier activity, resulting in the increased CO2 transport compared to the previous system. [Copyright &y& Elsevier]

In search of small dielectric constant(Dk) and low-dissipation (Df) energysubstrates for high-frequency appliances, a benzoate-group-substitutedbisphenol A based resin was synthesized from bisphenol A dibenzolateand bisphenol A diglycidyl ether. Compared to the common bisphenolA diglycidyl ether epoxy resin, introduction of the benzoate groupwas considered to lead to increased hydrophobic character, which wassupported by water absorption investigation as well as absorptionpeak investigation of the OH region via Fourier transform infraredspectra. The cured resin with few water molecules exhibited restrictedmotion of the segment, and, consequently, thermally stable properties(coefficient of thermal expansion and thermogravimetric analysis)were achieved. Ultimately, the developed epoxy resin showed dramaticallyreduced Dk(3.05 at 1 GHz) and Df(0.016 at 1 GHz) values as well as enhancedadhesive properties. The excellent overall properties lead to itspromising use in various fields involving electrical devices. [ABSTRACT FROM AUTHOR]

Poly(2,2,6,6-tetramethylpiperidinyloxy-4-yl methacrylate-co-styrenesulfonate) was prepared and utilized as a Li+ host material for a cathode in a Li-ion battery. The polymer allowed high density incorporation of the Li+ ion per repeating unit at a positive redox potential near 0.6 V vs. Ag/AgCl. Redox equilibrium involving the Li+ migration was proved by the theoretical approach based on the Nernst equation as well as a microgravimetry analysis using an electrochemical quartz crystal microbalance technique. A cell fabricated with the polymer as the cathode-active material showed a high power rate capability with an average discharging potential near 3.9 V vs. the lithium metal anode. [ABSTRACT FROM AUTHOR]