Hydrangea-like zinc oxide superstructures for ferroelectric polymer composites with high thermal conductivity and high dielectric constant

Polymer composites with high thermal conductivity and high dielectric constant are highly desirable in electronic and electric industry, and particularly, for power apparatus at high voltages. In this work, a novel hydrangea-like ZnO superstructure was prepared by a template-free solvothermal method. Polyvinylidene fluoride (PVDF) composites filled with the ZnO superstructure were prepared via a solution mixing method. The microstructure, thermal conductivity, thermal stability and dielectric properties of the composites were investigated. It was found that the hydrangea-like ZnO shows marginal influence on microstructure of the PVDF matrix, but has significant enhancement effects on thermal conductivity, thermal stability and dielectric constant of the composites. Compared with the commercial ZnO nanoparticles, the hydrangea-like ZnO superstructures result in much higher enhancement of thermal conductivity and dielectric constant and slightly lower breakdown strength of the composites. This has been ascribed to the formation of percolation-like structure in the hydrangea-like ZnO composites.