School of Material Engineering, Jinling Institute of Technology, Nanjing, 211169, People's Republic of China.
J Chem Phys. 2012 Jul 28;137(4):044907. doi: 10.1063/1.4737664.
Using an atomistic molecular dynamics (MD) simulation, we study the volume relaxation behavior of atactic polystyrene and attempt to correlate this macroscopic behavior with certain microscopic aspects. To this end, the gyration radius, the dimensionless relative shape anisotropy, the mean-squared displacement, and the non-Gaussian parameter are examined simultaneously. Our result shows that the structures characterized at different length scales change in a self-similar way and these changes are intimately correlated to the translational mobility of atoms. The initial incubation of structural changes at the different scales originates from the restriction of mobility due to the cage effect. The applicability of the MD simulation to the investigation of the bulk properties is discussed.
我们使用原子分子动力学（MD）模拟来研究无规聚苯乙烯的体积弛豫行为，并尝试将这种宏观行为与某些微观方面相关联。为此，我们同时考察了回转半径、无量纲相对形状各向异性、均方位移和非高斯参数。结果表明，在不同尺度上所描述的结构以自相似的方式发生变化，这些变化与原子的平移迁移率密切相关。不同尺度上结构变化的初始潜伏期源于笼效应导致的迁移率受限。还讨论了 MD 模拟在研究本体性质中的适用性。
