Department of Chemical Engineering & Materials Science, UC Davis, One Shields Avenue, Davis, California 95616, USA.
J Phys Chem B. 2013 Apr 18;117(15):4134-41. doi: 10.1021/jp3118117. Epub 2013 Apr 3.
Opposing polymer brush layers at high grafting density were examined under confinement and characterized with respect to structure and interaction forces using molecular dynamics simulations in an explicit solvent. The brush system underwent a static compression, where the system is simulated at several discrete separation distances. These simulations are all at the same solvent chemical potential as a non-interacting reference state to produce a realistic compression. Normal pressure-distance profiles were generated and compared to density profiles at each separation distance to determine structure-property relationships. Significant interpenetration of brush layers occurred at high compression, to the extent that each brush reached the opposing surface. Higher interpenetration corresponded to a sharp increase in the pressure-distance curve, suggesting a correlation between interpenetration and interaction forces. We find clear differences from literature values using implicit solvent techniques.
高接枝密度下的 opposing polymer brush layers 在受限环境下进行了研究，并使用显式溶剂中的分子动力学模拟来研究其结构和相互作用力。在静态压缩下，brush system 在几个离散的分离距离下进行了模拟。这些模拟与非相互作用参考状态的相同溶剂化学势下进行，以产生实际的压缩。生成了正常的压力-距离曲线，并与每个分离距离的密度曲线进行了比较，以确定结构-性能关系。在高压缩下，brush 层发生了明显的相互渗透，以至于每个 brush 都达到了对面的表面。更高的相互渗透对应于压力-距离曲线的急剧增加，表明相互渗透和相互作用力之间存在相关性。我们发现与使用隐式溶剂技术的文献值存在明显差异。
