High performance of hydroxylated BiFeO3/polystyrene composite films with enhanced dielectric constant and low dielectric loss

摘要

In today's world, technology for capacitor applications have rapidly increased the interest for the development of perfect composite materials (polymers and ceramics) with enhanced dielectric properties. In the present work, the composites with bismuth ferrite (BiFeO3, BFO) particles as functional fillers and polystyrene (PS) as polymer matrix was prepared by solution casting technique. To improve the dielectric properties of the composites, the surface of BFO particles were chemically treated with H2O2 to introduce -OH groups. The experimental results show that the hydroxylated BFO-PS composites enhanced the dielectric constant, AC electrical conductivity and the dielectric loss is relatively suppressed. The surface hydroxylated BFO particles were more homogeneously dispersed into the PS matrix and it was confirmed by scanning electron microscopy (SEM). Moreover, the ferroelectric properties of the composites were significantly improved and a maximum remnant polarization (2P(r) = 1.442 mu C/cm(2)) was obtained in the composite materials as compared with BFO-PS at the same volume fraction of fillers. The thermal properties of the resultant composite films were investigated by using differential scanning calorimetry (DSC) method. The demonstrated approach may provide a route for using the hydroxylated ceramics to enhance the dielectric properties in ceramic-based polymer composites.