Investigation on the dielectric properties of nano-titanium dioxide — low density polyethylene composites

Dielectric properties of nano-titanium dioxide (TiO₂) with diameter about 25 nm - low density polyethylene (LDPE) composites were investigated at the temperature ranging from 293 K to 343 K with the frequency ranging from 0.1 Hz to 100 kHz in the present paper. Experimentally, we observed two peaks in the spectrums; one appears in both pure and incorporated LDPE (abbreviated as peak A) while the other appears only in the samples with nano-TiO₂ content exceeding 1 wt% (abbreviated as peak B). The activation energies calculated from dielectric spectrum for peak A and peak B are 1.09 eV and 0.8 eV respectively; they are independent of the concentration of TiO₂ nanofiller. Furthermore, the position of peak B is also independent of the nano-TiO₂ content in the frequency spectrums. Thus, it is reasonable to conclude that peak B is intrinsic, corresponding to the a response of LDPE while peak A may originate from the traps at the “Interaction Zone” around the nanoparticles. The dielectric properties of nanocomposite were determined by such “Interaction Zone”.