An experimental study of the charging regime of the composite (PANI5%/PMMA)

The charge dynamics of insulating or weakly conductive materials can be studied by the secondary electronic emission (SEE) method. Those two types of compounds behave differently to irradiation: charge trappers such as PMMA or SiO2 can have a charge excess after irradiation, so that they can be trapped for a long time, and can even cause 'microbreakdowns' to dielectric breakdowns, while in contrast, conductive materials have a kind of charge flow. SEE yield can also be affected by changing the current density. When the current density increases, the SEE intrinsic yield sigma(0) and the SEE stationary yield sigma(st) decrease. Unexpected behaviour of negative charging is observed showing that there must be competition between diffusion and accumulation effects.