Polyethylene oxide (PEO) - Liquid crystal (E8) composite electrolyte membranes: Microstructural, electrical conductivity and dielectric studies

A series of flexible and free standing composite membranes based on polyethylene oxide (PEO) and the nematic liquid crystal (LC) E8 were prepared using solution casting technique. The effect of the LC concentration on the structural modifications of PEO/E8 LC composites was investigated by Fourier transform IR spectroscopy, X-ray photoelectron spectroscopy (XPS), micro-Raman and differential scanning calorimetry (DSC). The electrochemical impedance measurements were performed in the applied frequency range of 0.1 Hz - 2 MHz. The dielectric properties of the PEO/E8 LC membranes were studied upon variation of the LC concentration and results were analyzed by Kohlrausch - Williams - Watts and Havriliak - Negami formalisms. These investigations pointed out that LC doped polymeric membranes display remarkable features that could be interested for their use as novel composite electrolytes for rechargeable metal ions batteries.