Adsorption of Organosilanes and Formation of Organo silicon Self-Assembled Nanolayerson the Aluminum Surface.Influence of Surface Nanolayerson Corrosion and Electrochemical Behavior of the Metal

Abstract

Adsorption of vinyl triethoxysilane and γ-aminopropyltriethoxysilane on the surface of aluminiumfrom aqueous solutions was studied by quartz nanobalance technique. Adsorption isotherms were obtained. It was shown that during adsorption silanes displace adsorbed water from the surface. To interpret the adsorption data, we used the well-known approaches of adsorption data: Langmuir, BET, Flory-Higgins, Langmuir multicenter,Temkin,Frumkinand Freundlichadsorption isotherms. The surface orientation of adsorbed molecules was determined. The silanes adsorption heats were calculated by different ways. It was shown that silanes are chemisorbed on the aluminium surface. By means of quartz nanobalance, atomic force microscopy, scanning electron microscope, Fourier transform IR spectroscopy it has been shown that an uniform, selfassembled, anti-corrosionvinylsiloxanenanolayer is formed on the aluminium surface during adsorption of vinyl silane from aqueous solution. This layer covalently bonded to the hydroxylsurface groups of the metal. The thickness of the surface nanolayer can be controlled by changing the deposition conditions. The effect of the vinylsiloxanenanolayer on the dissolution of aluminium in chloride-containing solutions has been studied. It was established that an ordered vinylsiloxanenanolayer, up to five molecular layers thickness, effectively inhibits the uniform and localized aluminium corrosion. It was shown that after 10 days of corrosion tests vinylsiloxanenanolayer is preserved on the aluminium surface, indicating its resistance to water and corrosive components.vinylsiloxane Keywords: Aluminium; Adsorption; Alkoxysilane;Organosilicon Self-Assembled Nanolayers; Heterogeneous Processes; Corrosion; Electrode Reactions; Corrosion Test