Computational Studies of Nano-Mechanics of Ultrathin Perfluoropolyether Films

In this work, molecular dynamics (MD) simulation was performed to investigate the nano-mechanics (i.e., compression and tension processes) of confined ultrathin perfluoropolyether (PFPE) lubricant films at near-contact head disk interface. During compression process, the lubricant film would transfer to the slider even before a full contact occurs; while during tension process, an apparent fluid bridge was observed. The entangled lubricant chains are gradually straightened until the film breaks apart into two parts in the nearly end of the tension process. The normal stress profiles of PFPEs were also evaluated in the two processes, in which the hypothesis phenomenon indicates the irreversible nature of the nano-mechanics of PFPEs.