Simulation of deposition of wax to iron oxide surfaces

Molecular dynamics techniques have been used to model the processes associated with the deposition of alkanes on a hematite surface, and the subsequent growth of an alkane crystal. First we have obtained a relaxed (0001)-hematite surface; this is believed to be the most common surface exhibited on the pipeline walls. Subsequently, the adsorption of two different linear alkanes has been examined: C-12 and C-28. The principal adsorption site for both has been determined and consisted of the molecule lying between two parallel rows of iron atoms. The subsequent addition of alkane molecules generates a crystalline structure, which corresponds closely with C-28 crystal growth along the (010) direction.