High-permittivity and low-dielectric-loss polymer composites based on TiO2-nanorod functionalized carbon nanotubes

High permittivity polymer-based composites have attracted increasing attention because of their inherent advantages of being easy to process, flexible and light weight in electronic and electrical industry. However, the permittivity of common polymer is very low (<;10). Adding conductive fillers provides a promising route to significantly increase the permittivity of a polymer with a low loading. Nevertheless, polymer composites containing conductive fillers often exhibit very high dielectric loss due to their large electrical conduction or leakage currents. In this paper, we report a simple and effective way to synthesize TiO₂-nanorod-decorated multi-walled carbon nanotubes (TD-CNTs). The resultant TD-CNT/polystyrene (PS) composites show high permittivity and low dielectric loss. The composites with 17.2 vol% TD-CNTs show a permittivity of 37 at 1 kHz, which is 13.7 fold higher than that of the pure PS, but the dielectric loss still shows a low level below 0.11.