论文标题
独立玻璃聚苯乙烯膜表面的能源障碍和合作运动
Energy barriers and cooperative motion at the surface of freestanding glassy polystyrene films
论文作者
论文摘要
我们研究了带有分子动力学模拟的独立式ATACTIC \ GLSDESC {PS}膜的近表面松弛。与以前的粗粒模拟一样，主链段和苯基环的松弛时间与它们的散装松弛时间通过功率法耦合关系有关。距表面距离的耦合指数的变化与深度依赖性激活屏障一致。我们还量化了界面上动态异质性的降低，这可以在用于玻璃动力学的合作模型框架中解释。
We investigate the near-surface relaxation of freestanding atactic \glsdesc{ps} films with molecular dynamics simulations. As in previous coarse-grained simulations, relaxation times for backbone segments and phenyl rings are linked to their bulk relaxation times via a power law coupling relation. Variation of the coupling exponent with distance from the surface is consistent with depth-dependent activation barriers. We also quantify a reduction of dynamical heterogeneity at the interface which can be interpreted in the framework of cooperative models for glassy dynamics.
