Surface treated ZnO whisker optimizing the comprehensive performance of the self-adaptive dielectrics

Abstract

The application of self-adaptive dielectrics (SADs) is a promising approach to enhancing the insulation performance as well as downsizing of most high voltage apparatus. Beside nonlinear electrical property, good thermal and mechanical performances of SADs are also expected. However, heavy load of functional fillers often leads to poor elasticity of traditional SADs and it is a challenge to decrease filler concentration while ensuring satisfied thermal and nonlinear electrical conductivity. In this paper, tetrapod-shaped ZnO whisker coated with oxides shell and its silicone rubber composites have been manufactured. The core-shell interface equips the ZnO whisker with nonlinear conducting behavior and the composites also exhibit similar self-adaptive electrical property like traditional SADs. Due to the relative large respect ratio, the coated whisker can reduce the filler concentration to about 10 vol% which guarantees good mechanical property of the material. The thermal conductivity of the composites and traditional SADs are compared and an optimized filler concentration range considering comprehensive property of the composite is obtained. This work is helpful to design smart composites to self-adaptively control high electrical field of electrical and electronic devices and increase their stability and durability.