论文标题
通过多粒子碰撞动力学模拟湿活性聚合物
Simulating wet active polymers by multiparticle collision dynamics
论文作者
论文摘要
嵌入流体中的活性布朗聚合物的构象和动力学特性取决于驱动机制的性质,例如自我刺激或单体的外部致动。呈现了多颗粒碰撞动力学(MPC)流体中的自旋细胞和驱动活性布朗聚合物的实现,从而捕获了两种驱动机制之间的明显差异。自旋细单体的无活力性质需要MPC模拟方案的适应,并具有其流和碰撞步骤,在碰撞步骤中必须省略单体自我突出速度。比较稀释溶液中活性聚合物的MPC模拟结果与通过Rotne-Prager-prager-Yamakawa张量计算流体动力学的Brownian动力学模拟的结果证实了实施的适用性。通过静态和动态结构因子分析了聚合物构象和动力学特性,并且讨论了后者相对于波数和时间依赖性的缩放行为。动态结构因子显示了各种活动引起的时间状态,具体取决于考虑的波数,这反映了整个聚合物在小波数下的持续扩散运动,以及在大波浪数下具有活性增强的内部动力学。将获得的仿真结果与理论预测进行了比较。
The conformational and dynamical properties of active Brownian polymers embedded in a fluid depend on the nature of the driving mechanism, e.g., self-propulsion or external actuation of the monomers. Implementations of self-propelled and actuated active Brownian polymers in a multiparticle collision dynamics (MPC) fluid are presented, which capture the distinct differences between the two driving mechanisms. The active force-free nature of self-propelled monomers requires adaptations of the MPC simulation scheme, with its streaming and collision steps, where the monomer self-propulsion velocity has to be omitted in the collision step. Comparison of MPC simulation results for active polymers in dilute solution with results of Brownian dynamics simulations accounting for hydrodynamics via the Rotne-Prager-Yamakawa tensor confirm the suitability of the implementation. The polymer conformational and dynamical properties are analyzed by the static and dynamic structure factor, and the scaling behavior of the latter with respect to the wave-number and time dependence are discussed. The dynamic structure factor displays various activity-induced temporal regimes, depending on the considered wave number, which reflect the persistent diffusive motion of the whole polymer at small wave numbers, and the activity-enhanced internal dynamics at large wave numbers. The obtained simulation results are compared with theoretical predictions.