Camphor sulfonic acid (CSA) doped polypyrrole (PPy) films: Measurement of microstructural and optoelectronic properties

Abstract

In this paper, camphor sulfonic acid doped polypyrrole have been successfully prepared using different weight percentages of camphor sulfonic acid (10–50%) dispersed in polypyrrole by solid state synthesis method. Films of CSA doped PPy were prepared by spin coating technique on a glass substrate. The effect of varying concentrations of CSA on the structure, morphology, optical and electrical properties of polypyrrole was explored using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) atomic force microscopy (AFM), UV–visible spectroscopy and two probe technique respectively. The presence of CSA in PPy matrix and their interaction was confirmed by using XRD and FTIR techniques. The dramatic change in the surface morphology has been observed with increasing content of CSA in PPy matrix. The AFM study shows porous uniform globular morphology. The UV–vis spectra of CSA doped PPy film was found to shift to a lower wavelength side as compared to those of observed in PPy, indicating synergetic interaction between dopant CSA and PPy. CSA doped PPy not only can maintain a good solubility but also enhance the electrical conductivity. The results of dc electrical conductivity shows that, increase in electrical conductivity of PPy with increasing content of CSA (10–50%) in PPy matrix.