Effect of Water on Mechanochemical Reactions of PFPE Lubricant Films: A Reactive Molecular Dynamics Study

Abstract

Using molecular dynamics with our developed reactive force field, we investigated the effect of water on the mechanochemical reaction of nanometer-thick perfluoropolyether D-4OH films at the head–disk interface of heat-assisted magnetic recording. Three types of reactions were observed: hydrolysis, end group–end group association (EEA) reaction, and end group–main chain association (EMA) reaction. The simulation results showed that water molecules accelerate the decomposition of D-4OH and such effect is more noticeable at low pressures than at high pressures. The presence of water induces hydrolysis and accelerates the EEA reaction, whereas the EMA reaction is greatly accelerated by pressure rather than water.