Core-shell structured dendritic CuO@TiO2 for high-k P(VDF-HFP) composites with suppressed dielectric loss and enhanced thermal conductivity

In this work, a core-shell dendritic CuO@TiO2 was constructed through a two-step chemical method. Structural analysis confirms the successful coating of TiO2 on the CuO and the dendritic morphology was maintained after the coating process. The composites were prepared by using ferroelectric P(VDF-HFP) as matrix and synthesized particles as filler. The introduction of fillers influences the melting and crystallization process of the polymer matrix without altering the composition. The insulator layer suppresses the conductivity and dielectric loss by blocking the charge carriers while the composites exhibit improved dielectric constant in the frequency wide range of 10(2)-10(6) Hz and enhanced thermal conductivity. The composite with 20% CuO@TiO2 exhibits a high dielectric constant of 51.7, low loss of 0.11 at 1 kHz and high thermal conductivity of 0.382 W/mK, showing huge potential for dielectric applications.