J. Flis, M. Kanoza
Feb 15, 2006
Citations
1
Influential Citations
70
Citations
Quality indicators
Journal
Electrochimica Acta
Abstract
Abstract One of the applications of silanes is to improve adhesion of organic coatings to metals. In this work, films of vinyl-triethoxy silane (VTES) on iron (Fe/VTES system) were used to study the effect of exposure to air on protective properties and on chemical transformations of silane films. After exposure to air for up to 12 days, impedance measurements were made in 0.01 M Na 2 HPO 4 , and surface analysis was carried out with AES, XPS and FTIR. Exposure to air resulted in an increase of charge transfer resistance of Fe/VTES, and led to chemical changes involving growth of iron oxides at the Fe/VTES interface, formation of SiO 2 and related species, formation of polysiloxanes and polymerisation of vinyl groups. These transformations include hydrolysis and probably also photochemical reactions with the participation of free radicals (formation of SiO 2 and polymerisation). Identified products can contribute to the improved protectiveness by enhancing the barrier properties and by inhibition of corrosion. It is suggested that apart from improving adhesion, silanes play an important role also by protecting against corrosion.