Amorphous Silica Np-Embedded-Polymer Nanocomposites with Enhanced Optical and Dielectric Properties

Abstract

Inorganic filler and polymer matrix based PP + SiO₂ nanocomposites have been prepared by the hot pressing method. The scanning electron microscopy (SEM) and X-ray diffractometer(XRD) were used for structure investigation. It was found that the average size of the nanoparticles is around 50 nm. Photoluminescence properties of PP + SiO₂ nanocomposite and the effect of concentration of the SiO₂ nanofiller on dielectric and electrical dispersion behavior of the nanocomposite have been investigated. Besides, it was shown that the dielectric permittivity of PP + SiO₂ nanocomposite samples was gradually increased with raising filler content. Furthermore, it was observed a significant decreasing in the values of the ε′ and δ parameters of the nanocomposites in the 10³-10⁶Hs frequency range for all concentrations of filler. This decrease perhaps associated with the interphase polarization of the PP + SiO₂ nanocomposites. It was also shown that PP + SiO₂ nanocomposite demonstrates wide-band photoluminescence in visible region (400-700nm) when the excitation wavelength is 370 nm. This is due to the defects of SiO₂ nanoparticles embedded in the polymer matrix, and more precisely, with presence of oxygen-deficiency centers.

Keywords:

• Amorphous silicon dioxide
• photoluminescence
• dielectric
• nanocomposites