Effect of self-assembly aggregation on physical properties of non-aqueous ionogels based on LMWG

Abstract

In recent years the low-molecular-weight gelators (LMWG) started to be used as a hardener for liquid electrolytes to create ionogels (OIG). The characteristic properties of gels created by LMWG, like thermal reversibility, very low critical concentration of the gelator, and huge versatility of possible compounds that can be used, were thought to give them advantage over commercial polymer gel electrolytes (PGE). However, the PGE are still dominating, mainly thanks to its superior mechanical resistance and wide temperature range when compared to OIG. The narrow temperature range of the gel phase existence in case of OIGs is the biggest disadvantage. This paper reports the interdisciplinary study on physical properties of created ionogels with nonaqueous electrolyte solutions of quaternary ammonium salts (TAMBr, TEABr, TBABr) and low-molecular-weight gelators for different molar concentrations of the electrolyte. It will be shown how the self-assembly aggregation phenomenon can be used to extend the temperature range of the ionogel phase existence. The thermal scanning conductometry (TSC) method was used to investigate the electric properties of the ionogels. To investigate the transport properties of the cations and solvent molecules in the gel and sol phase, the NMR diffusometry method was used. For identification of intermolecular interaction in studied systems, the NMR spectroscopy method was used and to study how the different salts influence on the properties of used solvent, the tuning-fork vibration viscosimetry method was used. [Figure not available: see fulltext.]