Improving dielectric properties of PVDF composites by obtaining the BT-Ni particles

Abstract

In the rapid development of modern science and technology, the dielectric materials with more extraordinary performance were extremely demanded in the electronic system fields. Nowadays, outstanding-performance polymers, which possess a high dielectric constant and flexibility but low dielectric loss have attracted great attention owing to their potential application in many cutting-edge industries, including microelectronics, aerospace, and aviation. In general, the polymers possess excellent flexibility and high breakdown strength, but their applications was limited by the low dielectric permittivity. Numerous efforts have been made to improve the dielectric permittivity of dielectrics by incorporating ceramic additives into polymer matrix. Unfortunately, the high dielectric permittivity needs high filler loading, which causes them to lose their flexibility and decreased breakdown strengths. Herein, the Ni nanoparticles was deposited on the surface of the BT particles to obtain the BT-Ni particles by electroless plating method. The phase composition and morphology were analyzed by X-ray diffraction and scanning electron microscopy, and the effects of BT-Ni filler on the dielectric properties of the composites were investigated in detail. It can be found that the high dielectric permittivity of the composites increased to 61 at 100 Hz when the content of BT-Ni filler was 20vol.%, which is 2.54 times higher than that of 20vol.% BT/PVDF (24) and even greater than that of 40vol.% BT/PVDF (56). The Ni nanoparticles was strong interaction deposited on BT particles, and this structure can effectively suppress the probability of the Ni nanoparticles to form a conductive networks in the PVDF polymer matrix, which can greatly depress the increase of dielectric loss tangent and conductivity of the BT-Ni/PVDF composites. These results indicated that the dielectric constant of the composites can be significantly improved by incorporating Ni conducting particles into the polymer matrix and that the interfacial polarization effect is an important feature of BT-Ni/PVDF composites. This work provides a simple and effective way for preparing nanocomposites with enhanced dielectric properties for use in the electronics industry.