Molecular dynamics simulation of mechanism of nanoparticle in improving load-carrying capacity of lubricant film

The properties of base oil and nano-lubricant film confined between two approaching walls under boundary lubrication were studied using molecular dynamics simulation. The nano-lubricant consists of one Cu nanoparticle and n-octane as base fluid. The load-carrying capacity of nano-lubricant was found to be much higher than that of the base oil. The nanoparticle improved the load-carrying capacity before rupture of the lubricant film. The effect of nanoparticles on lubricant film structures was analyzed to determine mechanisms responsible for these results. Firstly, because of an adsorption layer around the nanoparticle, the nano-lubricant molecules become more organized and compact compared with base oil. Secondly, the soft Cu nanoparticle is deformed by the structural characteristics of the nano-lubricant film, which provides good support for the lubricant film. (C) 2015 Elsevier B.V. All rights reserved.