Comparative study of the electrodeposition of polybithiophene films on titanium electrodes: bare and modified with aromatic and aliphatic thiols

Polybithiophene films were electrochemically grafted onto titanium electrodes by potentiostatic and potentiodynamic methods in an acetonitrile/LiClO4 solution. The presence of an oxide layer at the Ti surface does not prevent direct electrodeposition of homogeneous polybithiophene films, but these films are not adherent to the substrate. A chemical pretreatment by thiols CH3-(CH2)9-SH and -(CH2)n-SH with n = 0–3 helps to reduce the metal dissolution and still allows the formation of electropolymerized films. However, it is noted that suitable adhesion of the polymer films to the substrate is only obtained with the phenylalkanethiols. For comparative purposes, results on the electropolymerization on platinum have been reported.