Influence of nanoparticle surface modification on the electrical behaviour of polyethylenenanocomposites

Abstract

In this study, we present the results of the influence of surface modification ofTiO2 nanoparticles on the short-term breakdown strength and space chargedistribution of low-density polyethylene (LDPE). A polar silane coupling agentN-(2-aminoethyl) 3-aminopropyl-trimethoxysilane (AEAPS) was used for thenanoparticle surface modification. Despite agglomeration and a poor interfacecompared to untreated nanoparticles, it was found that the incorporation of polargroups onto the nanoparticle surface improved both the dielectric breakdownstrength and space charge distribution as compared to samples filled with untreatednanoparticles. Microstructure studies showed that the presence of polar groups on theTiO2 nanoparticle surface did not evidently affect the degree of crystallinity, crystallinemorphology (except for internal spherulitic order), and chemical structure of the polymermatrix. The improved dielectric breakdown strength was therefore concluded to be directlydue to beneficial effects related to the variation of the electrical features at theparticle surface due to introduction of polar groups. For the same reason, with theuse of surface modified nanoparticles, formation of space charge was suppressed.