ナノ厚さ液体潤滑膜のせん断特性に及ぼす分子化学構造の影響

（粗視化分子動力学法による解析）

抄録

To design better molecules for nanometer-thick liquid lubricant films, it is important to understand how chemical structures of lubricant molecules affect viscous properties of the films. To conduct molecular dynamics (MD) simulations for obtaining such understandings, we developed coarse-grained (CG) molecular models of three types of perfluoropolyethers different in end group polarity and main-chain structure. These CG models reproduced the structural properties of the lubricant molecules derived from all-atom MD simulations. Using the models, we then conducted MD simulations of nanometer-thick liquid lubricant films subjected to confined shear between carbon surfaces with random roughness. We confirmed that, for roughness with short correlation length, the shear stress increased with increasing shear resistance among the liquid lubricant molecules due to the polarity of their end groups or the rigidity of their backbones.