Surface potential decay on LDPE and LDPE/Al2O3 nano-composites: Measurements and modeling

Surface potential decay on LDPE and LDPE/Al
₂
O
₃
nano-composite films charged by positive corona was studied. Potential distributions and decay on charged samples were measured using non-contact technique under ambient conditions. Results show that addition of 3 wt% of Al
₂
O
₃
nano-filler drastically slows down the decay process, confirming this way modification of the charge transport process. The obtained decay characteristics are analyzed by considering various decay models, based on intrinsic conduction, dielectric polarization, surface charge de-trapping as well as charge injection and its transport. Applicability of the first three models is analyzed in terms of derived quantities such as material conductivity, potential decay rate and trap density distribution whereas the latter one is examined by means of computer simulations. Among the studied models, the ones based on dielectric polarization and charge transport provide best fits to potential decay characteristics.