The slow polarization phenomena of interfaces between particles of micro-SiO2 or nano-SiOx and low-density polyethylene

The nano-SiO_x/low-density polyethylene (LDPE) and micrometer-SiO₂/LDPE composites were prepared by the double-solution method and 7 μm thin films were prepared by the spin-coating method. The characteristics of discharging current vs. time of pure LDPE and the composites containing nano-SiO_x or micrometer SiO₂ were measured, respectively. The dielectric spectra of ε\´(ω)IXepsiv;"(ω) and tanδ(ω) were investigated by Fourier transform method in frequency domain. It is found that the slow polarization in the nano-SiOx/LDPE composite differs from those of the micrometer SiO₂/LDPE composite and pure LDPE distinctly. It also can be seen that the polarization peak of the nano-SiOx/LDPE composite is much lower than that of LDPE in frequency domain, as well as the location of polarization peak of the nano-SiOx/LDPE is lower than that of LDPE in frequency domain. The slow polarization of all samples was discussed in detail at last.