A study of thermo-electric power and transport properties of polypyrrole/ash (paddy husk) nano-composites

Abstract

The polypyrrole (PPy)/ash (paddy husk) (PH ash) nano-composites were synthesized in the presence of ammonium persulphate (oxidizing agent) with different compositions, viz. 15, 30, 45 and 60 wt% of ash in the pyrrole, by chemical polymerization (oxidation) method. The Powder X-ray diffraction patterns showed that the PPy/PH ash nano-composites exhibited a high degree of amorphousness with only a low degree of crystalline structure. Scanning electron micrographs revealed that the particle sizes of the nano-composites increased when compared with the pure PPy and ash particles, and they had spherical as well as elongated forms. The PPy/PH ash nano-composite (45 wt%) showed the highest conductivity which may be due to the increased chain length of pure PPy which facilitated the hopping of the charge carriers and the larger number of charge carriers to hop between the favorable localized sites. Hence, the composites might be good semiconductors. The results of Seebeck coefficient and thermo-electric power factor experiments of the nano-composites demonstrated a strong dependence on the weight percent of ash in pure PPy. These nano-composites showed the behavior of thermo-electric materials. The nano-composites have also shown good dielectric behavior. So, the composites might be good materials of dielectric.