Charge transfer in thin layers of polymer nanocomposites based on aromatic thermoplastic polyimide and cerium dioxide

The results of the study of the electric charge transfer processes in R-OOD polyimide films and in nanocomposite based on it with cerium dioxide are presented. Using the existing model of charge barrier hopping (CBH), the values of the charge transfer parameters, such as the carrier concentration N, free path length R_ω, and potential barrier height W_M are calculated. The activation energy of conductivity processes is determined for all samples. The experimental results made it possible to draw following conclusions about the effect of the filler on the polymer matrix:the power-law nature of the frequency dependence of the specific conductivity σ'(ω) and the decrease in the exponent s with an increase in temperature in a wide range of frequencies and temperatures indicate the existence of a hopping mechanism of conductivity in the R OOD + CeO₂ composite; charge transfer is a thermally activated process with an activation energy of E = 0.077 eV for R-OOD and E = 0.070 eV for R-OOD + CeO₂; the introduction of 3% CeO₂ filler into the R-OOD matrix leads to an increase in the specific conductivity in the low-frequency region and a change in the nature of the hopping mechanism of conduction.