Molecular dynamics simulations of sliding friction of Langmuir–Blodgett monolayers
Molecular dynamics simulations of sliding friction of Langmuir–Blodgett monolayers
复制标题
Langmuir-Blodgett 单分子层滑动摩擦的分子动力学模拟
DOI：
10.1063/1.472442
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发表时间：
1996
影响因子：
4.4
通讯作者：
M. Yoneya
中科院分区：
文献类型：
--
作者：
A. Koike;M. Yoneya
采用分子动力学模拟方法研究了全氟羧酸和羟基羧酸在SiO2上的Langmuir-Blodgett单层间的摩擦。研究发现，全氟羧酸的摩擦力大约是羟基羧酸的三倍。该模拟结果的定性方面与已知的实验结果一致。为了解释摩擦力的差异，通过改变分子势参数进行了一系列的模拟。模拟结果表明，1-4范德华相互作用是导致全氟羧酸比羟基羧酸摩擦力更大的主要原因。结果还表明，摩擦力大致与平衡状态下剪切势能的超额均方根波动成正比。讨论了剪切条件下分子变形所需能量与摩擦力之间的关系。
Molecular dynamics simulations have been used to study friction in Langmuir–Blodgett monolayers of perfluorocarboxylic acid and hydrocarboxylic acid on SiO2. The frictional force of perfluorocarboxylic acid is found to be about three times as large as that of hydrocarboxylic acid. The qualitative aspects of this simulation results are consistent with known experimental results. In order to interpret the difference in the frictional force, a series of simulations have been carried out by changing molecular potential parameters. The simulation results suggest that the 1–4 van der Waals interaction is the main cause of the larger frictional force for perfluorocarboxylic acid than that for hydrocarboxylic acid. The results also show that frictional force is roughly proportional to the excess root mean square fluctuation of the potential energy under shear from the equilibrium. The relation between the frictional force and the energy needed for molecular deformation under shear condition is also discussed.