Computational chemistry study on the dynamics of lubricant molecules under shear conditions

Molecular dynamics simulations were performed to investigate the dynamic behavior of three kinds of perfluoropolyether molecules under constant shear and pressure conditions. Lubricational properties of these lubricants confined between two solid surfaces were calculated under different temperatures. The layered structures were observed for all lubricant. However lubricational properties of these lubricants were different. These differences can be explained by bridging structures between layers, because the bridging structures were one of the factors that controls lubricational properties due to their resistance in shear conditions. We investigated the influence of flexibility in lubricant molecules. As a result, we found that flexible molecules show stable lubricational properties under a wide range of temperatures.