Synthesis of polypyrrole/zinc oxide composites and study of their structural, thermal and electrical properties

Intrinsically conducting PPy/ZnO composites were synthesized with varying amounts of zinc oxide (0-20 wt.%) via a facile chemical oxidation polymerization approach. These composites were characterized for their structure, thermal stability, surface morphology and DC electrical conductivity by XRD, FT-IR, TGA, DSC, SEM and four-probe method respectively. FT-IR results show broadening and shifts of peaks towards lower wave numbers in all composites suggesting better conjugation and some chemical interactions between PPy and ZnO particles. Powder X-ray diffraction analysis demonstrated the amorphous nature of PPy and its composites as well with no indication of crystalline peaks. The percolation threshold for conductivity of PPy/ZnO composites was 15 wt.% of the volume fraction of PPy. SEM and TGA data suggest that PPy/ZnO composites have high thermal stability clue to better conformation, compactness and reduction of grain boundary volume with zinc oxide particle loading that in parallel enhanced their DC conductivity. (C) 2011 Elsevier B.V. All rights reserved.