氢及其同位素在聚苯乙烯与Cu界面的扩散

为了探索气体在固体表面高分子链中的扩散，使用分子动力学（MD）的方法，对H2，D2，T2在聚苯乙烯与金属铜（PS-Cu）界面的扩散进行了计算模拟，通过所得到气体的均方位移计算了气体在不同金属表面与聚苯乙烯界面中的扩散系数。结果显示:气体在界面的扩散系数比在聚苯乙烯本体中的扩散系数小，气体在PS-Cu(110)界面的扩散系数最大，在PS-Cu(111)界面的扩散系数最小。计算和分析了PS与金属表面的相互作用，发现其相互作用能越大，气体在此界面的扩散系数越小。同时，金属表面的晶面密度对气体在界面中的扩散也有一定的影响。

Diffusion of hydrogen and its isotopes in polystyrene-Cu interface

In order to explore the diffusion of gas in the polymer chain and solid surface, molecular dynamics (MD) method is used to simulate the diffusion of H₂, D₂, T₂ in the interface of polystyrene-Cu (PS-Cu). Their diffusion coefficients are obtained from the mean square displacement (MSD) of these gases in different metal surfaces and polystyrene interfaces. Results show that the diffusion coefficients of these gases in the interface are smaller than those in polystyrene itself, and the diffusion coefficients of these gases in PS-Cu (110) interface are the largest, while in PS-Cu (111) interface they are the smallest. Through calculation and analysis of interaction between PS and metal surface, we also found that the bigger the interaction energy is, the smaller the diffusion coefficient of gas in the interface becomes. Moreover, crystal density of the metal surface has a certain effect on the diffusion of gas in the interface.