Transport properties of nanoscale lubricant films

Off-lattice molecular dynamics simulations based on the coarse-grained bead-spring model via the Langevin equation were performed to simulate the dynamics of a confined nanoscale perfluoropolyether film (i.e., the self-diffusion and relaxation processes). The effects of molecular weight and solid surface attraction on the film diffusion coefficient were studied using the Green-Kubo formula. Via a stretched-exponential model, we investigated the relaxation process of nanofilms, and found that the relaxation spectra were stretched from the exponential decay process for functional endgroups and/or surface attraction.