Conductivity anisotropy of polyphosphazene-montmorillonite composite electrolytes

The conductivity of an ordered polyphosphazene Na+-montmorillonite composite has been measured perpendicular (sigma(para)) and parallel (sigma(perp)) to the montmorillonite layers, and the sigma(para)/sigma(perp) is about 100. The temperature dependence of the conductivity is consistent with a coupling between long-range Na+ movement and high-amplitude segmental motion of the polymer. The anisotropy is attributed to greater tortuosity of the Na+ diffusion perpendicular to the montmorillonite layers.