Deposition and morphology of direct current plasma-polymerized aniline

Abstract

Plasma polymerization is a simple, solvent-free, dry process that involves vaporizing a monomer and ionizing them to the plasma state. This study reports the plasma polymerization of aniline in a direct current glow discharge. Aniline was introduced into a vacuum chamber and plasma-polymerized onto an indium-doped tin oxide/glass substrate at varying discharge potentials and deposition times. The resulting plasma-polymerized aniline films were in the leucoemeraldine form, as evidenced by UV-Vis and infrared spectral analyses. Monocarbon species that are products of the aromatic ring rupture were observed from the optical emission spectra of the discharge. The films reveal a smooth, pinhole-free surface across different process parameters. The film thickness from the 200 to 600 nm range presents a linear relationship with respect to the duration of deposition. The deposition rate also increased and has a good linear relationship when the discharge potential was varied.