Electrodeposition of Methylated Sol-Gel Films on Conducting Surfaces

A new approach to sol-gel film formation, involving electrochemical control of the pH near a conductive surface, is described here, in which methyltrimethoxysilane (MeTMOS) is deposited onto indium-tin-oxide and gold surfaces. The method is based on a “two-step” sol-gel preparation procedure in which MeTMOS is first pre-hydrolyzed and then polycondensed. A constant negative potential is applied to the electrode surface, increasing the concentration of hydroxyl ions, which act as a catalyst in the condensation process. This results in greater control over the deposition process and thus over film properties.