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Novel ion-gels bearing lithium borate were synthesized via condensation between cellulose and boric acids in IL. Ion-gels obtained showed high ionic conductivity comparable to IL itself. First, ion-gels containing 5 wt % and 7 wt % of cellulose were prepared in 1-allyl-3-ethylimidazolium chloride. Their ionic conductivities were evaluated by ac-impedance method after drying ion-gels thoroughly. The ion-gel including 5 wt % of cellulose exhibited higher conductivity than that including 7 wt % of cellulose. This should be because of lower activating energy under lower composition of cellulose. The effect of concentration of C6F5B(OH)2 on ionic conductivity was also examined with varying the ratio of B(OH)3 and C6F5B(OH)2. It was demonstrated that the ion-gel including greater amount of pentafluorophenylborate showed significantly enhanced ionic conductivity. Preparation of ion-gels including 1-allyl-3-ethylimidazolium formate was also examined at the cellulose concentration of 7 wt %. The ion-gels synthesized in 1-allyl-3-ethylimidazolium formate showed higher ionic conductivity (1.98 x 10-3 Scm-1; 30 °C) than that synthesized in 1-allyl-3-ethylimidazolium chloride. This should be because of lower viscosity of 1-allyl-3-ethylimidazolium formate. [ABSTRACT FROM AUTHOR]

Abstract: Novel organoboron ion-gel electrolytes bearing boric ester were prepared under a mild reaction condition by dehydrocoupling of cellulose with hydroborane in ionic liquid. The organoboron ion-gels obtained showed ionic conductivity of 6.3×10−4–1.1×10−4 Scm−1 at 324K. The desired ion-gels were successfully prepared during the reactions for 1h. The ion-gels prepared using mesitylborane showed higher ionic conductivity in comparison with ion-gels prepared from BH3–THF complex. Different from ordinary polymer ion-gels, the addition of lithium salt led to further increased ionic conductivity. This should be due to the high dissociation degree of LiCl in the presence of boron, as indicated from increased VFT (Vogel–Fulcher–Tammann) parameter corresponding to carrier ion number in the matrices. [Copyright &y& Elsevier]

Abstract: Novel supramolecular type solid polymer electrolytes were prepared by self-assembly of diborylated ionic liquid in the presence of bifunctional ligands. The polymers obtained were well soluble in methanol, and their structures were supported by 1H and 11B NMR spectra. The ionic conductivity of the polymers was evaluated by ac-impedance method after the samples were dried thoroughly. The ionic conductivity observed was 8.8×10−6 to 5.4×10−6 Scm−1 at 51°C in the presence of equimolar amount of LiTFSA to ionic liquid unit. The temperature dependence of ionic conductivity was successfully fitted to VFT (Vogel–Fulcher–Tamman) plots, indicating that ionic conduction is taking place according to typical ion transport model in viscous matrix. [Copyright &y& Elsevier]

Abstract: In the present study, a novel ionic liquid including o-carborane anion was prepared. After the carbene formation of 1-ethyl-3-methylimidazolium halide ([EMIm]+[X]−) by reaction with n-BuLi, the subsequent reaction with o-carborane afforded the desired ionic liquid in moderate yields. The structure of the ionic liquid was supported by 1H NMR and 11B NMR spectra. [Copyright &y& Elsevier]