SOLUBLE CONDUCTIVE POLYPYRROLE SYNTHESIZED BY IN-SITU DOPING WITH BETA-NAPHTHALENE SULFONIC-ACID

Soluble polypyrrole (PPy) with high conductivity (27 S/cm) has been pr epared by chemical polymerization of pyrrol monomer in the presence of beta-naphthalene sulphonic acid (NSA) as a dopant. The solubility of the resulting conducting polymer of PPy-NSA in m-cresol increases with increasing the concentration of NSA in the polymerization media, and the highest solubility of PPy-NSA in m-cresol is about 1.2 g/100 mt. T he room-temperature conductivity of PPy-NSA significantly increases wi th the concentration of NSA when the concentration of NSA is less than 0.1 mol/L, while it slightly decreases with increasing the concentrat ion of NSA after the concentration of NSA is higher than 0.1 mol/L. UV -VIS spectra and ESR measurements demonstrate that both polaron and bi polaron are present as a charge carrier. The resulting PPy-NSA exhibit s unusual fibrillar morphology with a diameter of about 0.5 mu m, whic h is quite different from the granular morphology of PPy doped with do decyl benzene sulfonic acid (DBSA) and HCl. Moreover, the polymerizati on conditions greatly influence the morphology of the obtained PPy-NSA . (C) 1997 John Wiley & Sons, Inc.