Preparation of core@dual-shell BT@TiO2@PDA nanoparticles and dielectric properties of BT@TiO2@PDA/PI composite films

Abstract

To improve the interface compatibility, dielectric properties and energy storage density of polyimide(PI)-based composite materials, the core@dual-shell nanoparticles, BT@TiO2@PDA were obtained via facile solution method using the dopamine to coat on the BT@TiO2 nanoparticles, which is barium titanate (BT) coated with amorphous-TiO2, hydrolyzed from tetra-n-butyl titanate (TBT). A series of modified BaTiO3/PI (BT@TiO2@PDA/PI) composites with different contents of BT@TiO2@PDA were prepared through a solution casting film formation method. The results show that the dispersion of nanofillers in the polymer matrix and the interface compatibility between them can be improved by utilizing core@dual-shell nano-structured BaTiO3. The permittivity κ of BT@TiO2@PDA/PI composite films with 40%(mass fraction) filler loading increase to 8.8 (1 kHz), which is about 2.7 times higher than that of pristine polyimide, 1.4 times higher than that of pristine BaTiO3/PI composite films. Temperature-dependent and frequency-dependent dielectric performance tests confirm that BT@TiO2@PDA/PI composites possess good temperature and frequency stability. In the frequency range of 100 kHz, the dielectric loss of the composites is less than 0.010; when the filler loadings are under 40%, the permittivity of the composites decreases by less than 0.6 (1 kHz) from 25 ℃ to 160 ℃.

Keywords

• batio3
• polyimide
• dielectric property
• core@dual-shell