Surface-enhanced Raman Spectroscopic Studies On Films Of Organofunctional Silanes On Metal Surfaces

Organofunctional silanes are organosilicon derivatives which has one or a few chemical active functional groups. With their characteristic structures and properties, the organofunctional silanes find extensive application in the areas of adhesion, corrosion, lubrication, catalysis and self-assembled monolayers (SAMS). Many of these applications are made on metals most practical to various branches of surface chemistry. So it is necessary to study the formation and structure of the films of organofunctional silanes formed on the metal surface, the nature of the bonding between metal and films, and the dynamic process and the mechanism accompanying the formation of the adsorbed species. In order to achieve above objectives, this thesis work deals with the following research work:Of the large variety of organofunctional silanes the y-aminopropyltrimethoxysilane (y-APS) is the most commonly used silanes . We prepared the uniform films of y-APS on various metal electrodes surface with proper methods. Characterization of the silane films was performed by X-ray photoelectron spectroscopy (XPS), in-situ surface-enhanced Raman spectroscopy (SERS), and Atom Force Microscopy (AFM).The contribution of this work is of importance in understanding the interfacial properties of y-APS on metal surfaces. The structure and properties of the interfacial region is different from the film bulk. The potential-dependent SERS spectra of the adsorptive groups on the surfaces were employed as the direct evidence to deduce the adsorptive orientation of y-APSmolecular. The supporting electrolytes have little influence on the adsorption of y-APS. AFM characterization showed the characteristic structure, it dues to the inducement of the surface with roughness. Other factors such as the time of films formation and the concentration of the solution of si lanes also play important roles in the process of films formation. We evaluated the category and properties of the adsorptive films and analyzed the mechanism of the adsorption of y-APS on electrodes surface in detail, the theoretic model was also proposed in this thesis.