Crystallinity, magnetic and electrochemical studies of PVDF/Co 3O4 polymer electrolyte

Abstract

Organic-inorganic nanocomposites are gaining importance in the recent times as polymer electrolyte membranes. In the present work, composites were prepared by combining nano sized Co<inf>3</inf>O<inf>4</inf> and poly(vinyledene fluoride) (PVDF), using spin coating technique. The surface of the PVDF/Co <inf>3</inf>O<inf>4</inf> system characterized through field emission scanning electron microscopy (FESEM) revealed a porous structure of the films. The nanoparticles tend to aggregate on the surface and inside the pores, leading to a decrease in the porosity with an increase in Co<inf>3</inf>O<inf>4</inf> content. Co<inf>3</inf>O<inf>4</inf> nanoparticles prohibit crystallization of the polymer. Differential scanning calorimetry (DSC) studies revealed a decrease in crystallinity of PVDF/Co<inf>3</inf>O<inf>4</inf> system with an increase in the oxide content. Magnetic property studies of the composite films revealed that with an increase in Co<inf>3</inf>O<inf>4</inf> content, the saturation magnetization values of the nanocomposites increased linearly, showing successful incorporation of the nanoparticles in the polymer matrix. Further, ionic conductivity of the composite films was evaluated from electrochemical impedance spectroscopy. Addition of Co<inf>3</inf>O<inf>4</inf> nanoparticles enhanced the conductivity of PVDF/Co<inf>3</inf>O<inf>4</inf> system. © 2011 Elsevier B.V. All rights reserved.