Study on the electrical properties of polypyrrole nanowires/silica composites

Abstract

Abstract In recent years, conductive composites have been attracted more attentions, but their applications and developments are restricted by the deficiency of the research on conductive mechanism. The electrical conductivity and percolation threshold of silica (SiO2) matrix with different particle sizes using polypyrrole nanowires (PPy-NWs) as fillers are experimentally investigated. The results show that the electrical properties of PPy-NWs/SiO2 composites typically exhibit a non-linear percolation behavior. PPy-NWs/SiO2 (30 nm) nanocomposites need more filler content to achieve percolation threshold compared to that of PPy-NWs/SiO2 composites with 2 µm SiO2 particles as matrix. The conductive behavior of these composites is the result of the interaction and competition of various conductive mechanisms. The difference in electrical properties of PPy-NWs/SiO2 composites with different particle size SiO2 as matrix is attributed to the effect of matrix size on tunnelling conduction and the establishment of conductive pathways. Moreover, a two-dimensional conductive network model filled with PPy-NWs and an effective electrical resistivity model of PPy-NWs/SiO2 composites were established. The simulation models can reflect the electrical properties of conductive composites, and are well agreement with the experimental data.