Easy Preparation and Useful Character of Organogel Electrolytes Based on Low Molecular Weight Gelator

Using N-carbobenzyloxy-l-isoleucylaminooctadecane as a low molecular weight gelator for polar solvents, organogel electrolytes were prepared from supporting electrolyte and a polar solvent such as DMF, DMSO, and PC by physical gelation. The ionic conductivity of the prepared organogel electrolytes decreased very slightly with increasing concentration of gelator, while the gel strength drastically increased with increasing concentration. The organogel prepared from DMF exhibited relatively high ionic conductivity, interpreted due to the high mobility of carrier ions in the low-viscosity DMF. Arrhenius plots of ionic conductivities of organogel electrolytes indicate that the behavior of supporting electrolytes in the organogels is essentially similar to that in the isotropic solution, and the ionic mobility of supporting electrolytes is scarcely affected by the gelator molecules. The optimal concentration of supporting electrolytes in organogel electrolytes to achieve both high conductivity and high gel strength was 0.05−0.2 M. The addition of PEG to organogel electrolytes markedly raised the gel strength without decreasing ionic conductivity.