Characterization of Plasma-Polymerized Thiophene Thin Films and Nanoparticles Synthesized by a Double-Discharge Technique

PTH nanoparticles and thin films were synthesized via a plasma polymerization technique using a double-discharge system. This system has a fast filamentary discharge formed from the superposition of an ordinary low-pressure dc glow discharge and a high-current pulsed one. The samples were characterized by SEM, TEM, XPS, UV-vis and FT-IR spectroscopy. We found that superposing two discharges allows to control the morphology of the films. In the high-temperature region, smooth and uniform thin films were produced, whereas gas-phase polymerization resulted in films with grains of irregular shape. However, the films produced in the gas-phase region exhibited highly thiophenic structures and could be dispersed in DCM, giving nanoparticles of 30 to 50 nm diameter.