Adsorption of Organosilanes on the Surface of Aluminium and the Formation of Organosilane Films to Protect It from Corrosion

Adsorption of diaminesilane (DAS), vinyltrimethoxysilane (VS) on the surface of thermally precipitated aluminium was examined. The use of different adsorption isotherms made it possible to calculate the adsorption heats for DAS and VS. It was determined that chemisorption of these organosilanes occurred on the surface of aluminium. Exposure of aluminium for 60 min to aqueous solutions of organosilanes led to the formation of organosilane films on the surface of the metal. The use of infrared spectroscopy and scanning electron microscopy in the work made it possible to assess the interactions of organosilanes with the metal surface, as well as to determine the structural features of the films and their thickness. Electrochemical and corrosion research methods made it possible to study the protective properties of organosilane films on aluminium.

Oxygen adsorption and diffusion on an Al(111) surface and subsurface: a theoretical study

The generalized gradient approximation of the density functional theory was used to investigate the adsorption and dissociation of the O2 molecule on an Al(111) surface and the subsequent diffusion of an oxygen atom into the subsurface with different oxygen coverages. The total adsorption energies of oxygen atoms on the Al(111) surface increase as the number of adsorbed oxygen atoms increases, while the adsorption heats per oxygen atom decrease firstly and then increase. The adsorption heats for O2 physisorption on the Al(111) surface would increase as the oxidization degree of Al(111) surface increased. As the oxidization degree of Al(111) surface increases, the adsorption heats for O2 chemisorption decrease firstly and then increase, and the O2 molecule would not dissociate when the oxidization degree was up to 1.0 monolayer. In general, the energy barriers for both the interlayer and intralayer diffusions of the oxygen atom on the Al(111) surface would become larger as the number of initial adsorbed oxygen atoms on the Al(111) surface increased due to an increasing repulsion force.