A molecular dynamics study on lubricant perfluoropolyether in hard disk driver

Abstract

The structure of nanoscale lubricant films perfluoropolyether (PFPE) and its mob ility on a solid surface are important for the service durability and reliabilit y of the computer head_disk device. Molecular dynamic simulations based on a coa rse_grained bead_spring model are adopted to investigate the static properties s uch as molecular conformation, bead density, end bead density and the dynamic pr operties such as self_diffusion coefficient as a function of the wall effect and the functionality effect of PFPE films. The simulation results of static proper ties show that there is a monolayer in surface layer for nonpolar PFPE, while th ere is a complex layered structure for polar PFPE. While the simulation results of dynamic properties show that the diffusivity of PFPE films is enhanced by wal l effect but decreased by the functionality effect.