Monte Carlo模拟随机共聚高分子在固/液界面的吸附行为

Monte Carlo simulation of adsorption of random copolymers at solid-liquid interface

用MonteCarlo方法对无规共聚高分子在固液界面的吸附进行模拟,获得了固液界面区吸附链节的分布和吸附构型大小的分布等微观信息,以及总链节和吸附链节密度分布、链附着率、表面覆盖率、吸附量和吸附层厚度等宏观信息.考察了吸附性链节的对比吸附能εAa和无规共聚高分子中吸附性链节比率f对它们的影响.结果表明,界面附近的高分子以尺寸较小的环式和卧式构型分布为主,而尾式构型分布较宽.当f增大时小环式构型迅速增加,卧式构型的分布则变宽.随着εAa和f的增大,链附着率、表面覆盖率和吸附量等均随之增加,而吸附层厚度变薄.

The Monte Carlo simulation method was used to simulate the adsorption of random copolymers on the solid/liquid interface. The microstructure information of adsorbed layer, such as adsorbed segment profile and distribution of sizes of various adsorption configurations, and the macrostructure information, such as total segment and segment density profiles, bound fraction, surface coverage, adsorption amount and adsorption layer thickness were obtained. In this work, the effect of attractive segment content f and its energy was investigated. It was shown that there were mostly smaller trains and smaller loops near the interface, but the distribution of loops configuration was wider. Small loops increased rapidly with increasing attractive segment content, and the distribution of train configuration became wider. As f and adsorption energy increased, bound fraction, surface coverage and adsorption amount also increased, but the thickness of adsorbed layer decreased.