论文标题
在气体液体共存的聚合物中，违反Stokes-Einstein和Stokes-Einstein-Debye关系
Violation of Stokes-Einstein and Stokes-Einstein-Debye relations in polymers at the gas-supercooled liquid coexistence
论文作者
论文摘要
分子动力学模拟是在模型线性聚合物系统上进行的，以查看在模式耦合理论温度$ t_c $ t_c $ t_c $的违规情况下的违规（SE）和Stokes-Einstein-debye（SED）关系，在三个（三个较高和两个较高）。在低温下，两个较低密度系统均显示稳定的气体液体并存，而较高的密度系统是同质的。我们表明，单体密度松弛均显示出所有三个密度的SE违规，而分子密度放松在两个较低密度系统中均表现出对接近$ t_c $的SE关系的较弱的违规。这项研究确定了典型的单体轨迹中单体迁移率的差异和jumplike运动的观察，从而导致侵犯SE。除了违规情况外，在较低密度的气体液体并存结构域中还观察到较弱的SED违规行为。两个较低密度系统还均显示了该聚合物系统中转化和旋转动力学的脱钩。
Molecular dynamics simulations are performed on a system of model linear polymers to look at the violations of Stokes-Einstein (SE) and Stokes-Einstein-Debye (SED) relations near the mode coupling theory transition temperature $T_c$ at three (one higher and two lower) densities. At low temperatures, both lower density systems show stable gas-supercooled-liquid coexistence whereas the higher density system is homogeneous. We show that monomer density relaxation exhibits SE violation for all three densities, whereas molecular density relaxation shows a weak violation of the SE relation near $T_c$ in both lower density systems. This study identifies disparity in monomer mobility and observation of jumplike motion in the typical monomer trajectories resulting in the SE violations. In addition to the SE violation, a weak SED violation is observed in the gas-supercooled-liquid coexisting domains of the lower densities. Both lower density systems also show a decoupling of translational and rotational dynamics in this polymer system.
