Experimental investigations of semi-crystalline plasma polymerized polypyrrole for surface coating

Plasma polymerized thin film of conducting polypyrrole were deposited at room temperature by plasma enhanced chemical vapor deposition method using pyrrole monomer as precursor. The radio frequency (RF: 13.56 MHz, power supply: 30 W) was applied at constant argon gas pressure for the formation of plasma. The as grown thin films of polypyrrole have been characterized by ellipsometry, Fourier transform infrared spectroscopy (FTIR), UV–vis spectroscopy, atomic force microscopy (AFM), X-ray diffractometry (XRD) and high-resolution transmission electron microscopy (HRTEM). UV–vis spectra showed the optical energy band gap of 2.3 eV. XRD pattern of plasma polymerized polypyrrole has revealed a clear peak at inter-planer separation of 0.687 nm. It was also noticed by HRTEM analysis that the distinguished reflection at d =  0.687 nm has a broadening effect that may be correlated with the crystallinity of the material.