arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1706.07166cond-mat.soft
收藏

活性流体中基于弹性的polymer分选:布朗动力学研究

Elasticity-based polymer sorting in active fluids: A Brownian dynamics study

Jaeoh Shin, Andrey G. Cherstvy, Won Kyu Kim, Vasily Zaburdaev

摘要:

虽然平衡介质中聚合物链的动力学现在已经很好地理解了,但活性非平衡环境中的聚合物动力学可能非常不同。在这里,我们研究的动态聚合物在粘性介质中含有自推进粒子在两个维度上使用布朗动力学模拟。我们发现,聚合物的质心表现出超扩散运动在短期到中期的时间和运动转向正常的时间长,但大大增强了扩散。有趣的是,长时间扩散率显示出作为链长和刚度的函数的非单调行为。我们分析了聚合物构象和自推进粒子的积累,以及聚合物的定向运动是如何相互关联的。在最大聚合物扩散率的点处,聚合物优先具有由链弹性和由活性颗粒产生的推进力之间的平衡维持的弯曲构象。我们还考虑了双阱势中主动驱动聚合物的势垒穿越动力学。的势垒跨越时间被证明有一个特殊的非单调的依赖关系,相关的扩散率。这种效应可以潜在地用于在\textit{in vitro}实验中从溶液中分选聚合物。

英文摘要:

While the dynamics of polymer chains in equilibrium media is well understood by now, the polymer dynamics in active non-equilibrium environments can be very different. Here we study the dynamics of polymers in a viscous medium containing self-propelled particles in two dimensions by using Brownian dynamics simulations. We find that the polymer center of mass exhibits a superdiffusive motion at short to intermediate times and the motion turns normal at long times, but with a greatly enhanced diffusivity. Interestingly, the long time diffusivity shows a non-monotonic behavior as a function of the chain length and stiffness. We analyze how the polymer conformation and the accumulation of the self-propelled particles, and therefore the directed motion of the polymer, are correlated. At the point of maximal polymer diffusivity, the polymer has preferentially bent conformations maintained by the balance between the chain elasticity and the propelling force generated by the active particles. We also consider the barrier crossing dynamics of actively-driven polymers in a double-well potential. The barrier crossing times are demonstrated to have a peculiar non-monotonic dependence, related to that of the diffusivity. This effect can be potentially utilized for sorting of polymers from solutions in \textit{in vitro} experiments.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑