Effect of nanoparticle size on space charge behavior of EVA-TiO2 nanocomposites

In this paper the results of space charge and conduction current measurements performed at different temperatures and electric fields on nanocomposites based on ethylene-vinyl-acetate are reported. The nanofillers are spherical TiO2 nanoparticles with a size ranging from 5 nm to 40 nm. The results show that the size of nanoparticles influences significantly electric properties of the final nanocomposite. The specimens containing the smallest nanoparticles, in fact, present better electric properties as a function of electric field and temperature. In particular, smaller space charge accumulation, lower conductivity and lower activation energy of the conduction process are detected with respect to both base material and nanocomposite with bigger nanoparticles.