Investigation on Optical, Morphological and Thermal Properties of Spray Coated Polypyrrole Film

Soluble polypyrrole has been synthesized by In-situ chemical oxidative polymerization method in aqueous solution of pyrrole monomer. The solution contained dodecyl benzene sulfonic acid (DBSA) as a dopant and ammonium persulfate (APS) as an oxidant. The reaction temperature was 20°C for 24 hours. The prepared polypyrrole was dissolved in m-cresol solvent. The solution was coated on glass substrate by spray coating technique at 200°C for 5 minutes. The attachment of sulfonic group is confirmed in the pyrrole structure by FTIR spectroscopy. The absorption of PPy film at 360 nm and 600 nm was confirmed by UV spectroscopy. The emission wavelength of the film was found at 415nm as well as the direct band gap of the polypyrrole was 2.8eV. XRD study shows the crystalline nature of the DBSA doped polypyrrole film. SEM graph reveals globular morphology and the presence of functional acid on PPY film surface. TGA graph shows good thermal stability of the film.