Langmuir-Blodgett膜摩擦分子动力学模拟和机理研究

采用分子动力学方法，模拟了在两块石英基板上由脂肪酸(C₁₅H₃₁COOH)组成的单层Langmuir-Blodgett (LB)膜间的摩擦特性，探究了超薄膜在滑动过程中的摩擦和结构机理.得出对于单层LB膜在滑动过程中，在速度小于60m/s时，随着速度的增大，其剪切压增大；在速度大于60 m/s时，剪切压随速度的增加而减小.其链的倾斜角随着滑动速度的增加而减小.单层膜内的分子之间以氢键方式形成了较大的分子簇，由此导致了剪切压呈现较长的周期性，但在单层膜之间无氢键形 关键词： 分子动力学模拟 朗缪尔布洛杰特膜 纳米摩擦 氢键

Study of friction between hydrocarboxylic acid Langmuir-Blodgett films and its mechanism using molecular dynamics simulation

Molecular dynamics simulation has been used to study the friction and structure mechanism of Langmuir-Blodgett films of hydrocarboxylic acid (C₁₅H₃₁COOH) deposited on the SiO₂ substrates at different sliding velocities. The results show that, for a certain monolayer, the shear pressure between the monolayers increases when the sliding speed is below 60m/s and decreases when the sliding speed exceeds 60m/s. The molecular tilt angle decreases as the velocity increases. The molecular clusters formed in the monolayers by the hydrogen-bond caused the long shear periods, but there is no hydrogen-bond between the monolayers.