多分散高分子在固液界面吸附层厚度的Monte Carlo模拟

在格子模型基础上用Monte Carlo方法模拟研究了多分散高分子在固液界面的吸附行为，重点考察了平均分布和正态分布两种不同链长分布形式的高分子在固液界面吸附层厚度的分布规律，模拟结果与概率统计模型计算的吸附层厚度分布趋势一致。随着系统温度升高，高分子链节热运动加剧，吸附层厚度的极值增大，大吸附层厚度的密度也有所增加。而链节吸附作用能的增大能显著压缩吸附层厚度，导致吸附层厚度极值分布前移，但固液吸附界面的表面覆盖率显著增大。高分子链长的分布形式对吸附层厚度有着显著的影响，平均分布的高分子体系对温度和链节吸附能以及高分子浓度的变化比较敏感。

Monte Carlo Simulations for Layer Thickness of Polydisperse Polymers at S/L Interfaces

The adsorption behavior of polydisperse polymers at solid-liquid interfaces was studied by the method of Monte Carlo simulations based on the lattice model, and effects of the polymer chain length in systems of both average and normal distributions on the adsorption layer thickness were evaluated. It is found that the distribution of adsorption layer thickness follows the same trend with that predicted by the probability statistics model for polydisperse systems in our former works15]. Results also show that when temperature increases, the maximum of adsorption layer thickness may increase due to thermal vibrations of polymer segments and the aggravation, but the total adsorption amount may decrease at the same time. The adsorption layer thickness may be evidently compressed by increasing the adsorption energies between polymer segments and interface sites, and the total adsorption amount may consequently increase. For polydisperse systems, the change in adsorption layer thickness is more sensitive to temperature, adsorption energy and the concentration of the total polymer segments in the average distribution than that in the normal one.