Molecular Dynamics Study of Mechanochemical Reactions of PFPE Lubricant Films in the Presence of Water and Oxygen

Abstract

Using molecular dynamics with our developed reactive force field, we investigated the effect of water and/or oxygen on the mechanochemical reaction of nanometer-thick perfluoropolyether D-4OH films at the head–disk interface of heat-assisted magnetic recording. The simulation results showed that the presence of oxygen, water, or both accelerated the mechanochemical reaction of D-4OH. For oxygen only, no decomposition reaction occurred, and oxidation reactions were observed in which an oxygen molecule was inserted between the C–C bond in the end group of D-4OH. In contrast, in the presence of water, hydrolysis decomposition reactions at the C–O bond in the end group of D-4OH occurred frequently, and polymerization reactions were also observed.