Dielectric behaviour of montmorillonite/cyanoethylated cellulose nanocomposites.

Madusanka, N and Shivareddy, SG and Eddleston, MD and Hiralal, P and Oliver, RA and Amaratunga, GAJ (2017) Dielectric behaviour of montmorillonite/cyanoethylated cellulose nanocomposites. Carbohydr Polym, 172. pp. 315-321.

Abstract

A dielectric nanocomposite based oncyanoethylatedcellulose (CRS) and MMT nanoclay was successfully prepared with different weight percentages (5%, 10% and 15%) of MMT. MMT nanoplatets obtained via sonication of MMT nanoclay in acetone for a prolonged period was used in the preparation of CRS-MMT nanocomposites. CRS-MMT thin films on SiO2/Si wafers are used to form metal-insulator-metal (MIM) type capacitors. At 1kHz CRS-MMT nanocomposites exhibited high dielectric constants (εr) of 71, 55 and 42 with low leakage current densities (10-6-10-7A/cm2) for nanocomposites with 5%, 10% and 15% weight of MMT respectively, higher than values of pure CRS (21), Na-MMT(10). Reduction of εr with higher MMT loading can be attributed to a network formation as evidenced via strong bonding interactions between CRS and MMT leading to a lower molecular mobility. The leakage is studied using conductive atomic force microscopy (C-AFM) indicates that leakage pathways are associated with MMT nanoplatelets embedded in the CRS polymer matrix.