A STUDY OF THE DEPOSITION OF 3-GLYCIDOXYPROPYLTRIMETHOXYSILANE ON ALUMINUM

The effect of solution pH and hydrolysis time on the adsorption of 3-g lycidoxypropyltrimethoxysilane from 1% aqueous solutions onto FPL-etch ed aluminum surfaces is measured by using grazing-angle Fourier transf orm infra-red spectroscopy. An analysis of the Si-O-X region of the sp ectra indicates the presence of only two fundamentally different speci es on the aluminum surface. One of these species appears to be correla ted with adherent silane films that cannot be removed readily by rinsi ng off the substrate, and the other with non-adherent silane that can be rinsed off. It is shown that hydrolysis time in solution has no eff ect on the amount of silane adsorbed onto the surface, indicating that the primary adsorption process is not through the interaction of sila nol bonds with the substrate but probably involves interaction between the silane molecule and the thin layer of contamination present on al l aluminum surfaces. The pH of the solution affects the nature of the adsorbed silane layer but has only a minor influence on the amount of adsorbed silane. (C) 1998 Elsevier Science Ltd. All rights reserved.