Xueguang Jiang

A polymer gel electrolyte using AlCl ₃ complexed acrylamide as a functional monomer and acidic ionic liquid based on a mixture of 1-ethyl-3-methylimidazolium chloride (EMImCl) and AlCl ₃ (EMImCl–AlCl ₃ , 1–1.5, in molar) as a plasticizer has been successfully prepared for the first time via free radical polymerization. The polymer gel electrolyte can be used for aluminium deposition and rechargeable aluminium ion batteries.

A new fluorinated and alkylated lithium malonatoborate salt, lithium bis(2-methyl-2-fluoromalonato)borate (LiBMFMB), has been synthesized for lithium ion battery application. A 0.8 M LiBMFMB solution is obtained in a mixture of ethylene carbonate (EC) and ethyl methyl carbonate (EMC) (1 : 2 by wt). The new LiBMFMB based electrolyte exhibits good cycling stability and rate capability in LiNi_0.5Mn_1.5O₄ and graphite based half-cells.

Polymers of intrinsic microporosity can be constructed in several minutes via mechanochemical synthesis.

Nanoporous ionic organic networks (PIONs) with a high ionic density (three cation–anion pairs per unit) have been synthesized by a facile S_N2 nucleophilic substitution reaction. Owing to the electrostatic and steric effect, those ionic networks with porous channels can stabilize and support gold (Au) nanoparticles (NPs) in 1–2 nm. The Au@PION hybrid materials used as a heterogeneous catalyst were highly active, selective, and stable in the aerobic oxidation of saturated alcohols.

We report in this article the synthesis of a series of thermo- and light-sensitive hydrophilic ABA linear triblock copolymers, poly(ethoxytri(ethylene glycol) acrylate-co-o-nitrobenzyl acrylate)-b-poly(ethylene oxide)-b-poly(ethoxytri(ethylene glycol) acrylate-co-o-nitrobenzyl acrylate) (P(TEGEA-co-NBA)-b-PEO-b-P(TEGEA-co-NBA)), with various NBA molar contents and the study of sol–gel transitions of their aqueous solutions. The copolymers were prepared by ATRP from a difunctional PEO macroinitiator; the polydispersity indexes of all polymers were o-nitrobenzyl groups, raised the LCST of thermosensitive blocks, and thus triggered a gel-to-sol transition at a constant temperature. Rheometry was employed to study the sol–gel transitions and gel characteristics. In addition, we studied the effects of polymer concentration and NBA content on sol–gel transition temperature (T_sol–gel) and gel properties before and after UV irradiation. The T_sol–gel increased with the decrease of polymer concentration; the critical gelation concentration for the triblock copolymer with a NBA content of 9.3 mol% was between 3 and 4 wt% before UV irradiation and between 5 and 6% after photocleavage of o-nitrobenzyl groups. The change of T_sol–gel was in general larger for the copolymer with a higher NBA content after UV irradiation.

This article reports on the synthesis of a well-defined hydrophilic ABA triblock copolymer composed of a poly(ethylene oxide) (PEO) middle block and thermo- and pH-sensitive outer blocks and the study of sol-gel transitions of its aqueous solutions at various pH values. The doubly responsive linear triblock copolymer, poly(methoxydi(ethylene glycol) methacrylate-co-methacrylic acid)-b-PEO-b-poly(methoxydi(ethylene glycol) methacrylate-co-methacrylic acid) (P(DEGMMA-co-MAA)-b-PEO-b-P(DEGMMA-co-MAA)), was prepared by atom transfer radical polymerization of a mixture of DEGMMA and tert-butyl methacrylate with a molar ratio of 100: 5 from a difunctional PEO macroinitiator and subsequent removal of tert-butyl groups using trifluoroacetic acid. Dynamic light scattering studies showed that the critical micellization temperature (CMT) of this ABA triblock copolymer in a 0.2 wt % aqueous solution was dependent on the solution pH and can be varied in a large temperature range (>20 degrees C). To study the sol-gel transitions, a 12.0 wt % aqueous solution of the triblock copolymer with a pH of 4.89 was made; its pH value can be readily changed and well controlled by the injection of either a 1.0 M HCl or a 1.0 M KOH solution. From rheological measurements, the sol-gel transition temperature (T(sol-gel)) versus pH curve was found to closely trace the CMT versus pH curve, though there was a shift. By cycling the solution pH between 3.2 and 5.4, we showed that the T(sol-gel) at a specific pH was reproducible. Moreover, multiple sol-gel-sol transitions were realized by judiciously controlling the temperature and pH simultaneously, demonstrating the possibility of achieving on-demand sol-gel transitions by using two external stimuli. In addition, the effect of polymer concentration on T(sol-gel) at pH = 4.0 was investigated. The sol-gel transition temperature increased with the decrease of polymer concentration and the critical gelation concentration was found to be between 4 and 6 wt %.