Nanostructured liquid-crystalline ion conductors based on linear carbonate moieties: effects of oligooxyethylene and alkylene spacers on self-assembled properties and ionic conductivities

Abstract

We here report rodlike liquid-crystalline (LC) molecules consisting of bicyclohexyl and linear carbonate moieties connected through flexible spacers for the development of nanostructured ion-conductive materials. The molecular assemblies of the linear carbonate-based rodlike compounds mixed with a lithium salt provide 2D ion-conductive pathways in the smectic LC phases. The LC materials containing polar oligooxyethylene spacers coupled with linear carbonate moieties have been shown to function as efficient ion conductors, while those containing nonpolar alkylene spacers form thermally stable and ordered smectic LC structures. Molecular dynamics simulations provide insights into the conformation and packing of the molecules containing oligooxyethylene spacers in the LC phases. The combination of flexible oligooxyethylene chains and linear carbonates may lead to design of new LC electrolytes with highly mobile 2D nanochannels for applications in energy devices.