Beneficial effect of pre-oxidization process on the formation of silane films on iron

Abstract

Silanization has been recognized as a novel and green pretreatment process of metals in the past decades. However, due to the difficulty of film formation, silanization technique has not yet been applied in industrial scale to carbon steels. In this paper pre-oxidation technique was employed in order to intentionally solve this problem. Both the chemical pre-oxidation and anodic pre-oxidation were found to benefit the formation of ferric hydroxide (FeOOH), and thereby facilitate the subsequent silanization process. The effect of hydroxylation of iron substrate on the adsorption kinetics of silane molecule was then theoretically illustrated by using molecular dynamics simulation. • Pre-oxidation of iron produces larger number of hydroxylated groups. • The improved number of hydroxylated groups facilitates the formation of silane films on iron substrate. • Molecular dynamic simulation is used to interpret the easier adsorption of silane molecule on the surface of FeOOH than on Fe.