School of Mathematical Sciences, University of Nottingham, Nottingham, NG7 2RD, UK.
Faraday Discuss. 2010;144:71-92; discussion 93-110, 467-81. doi: 10.1039/b901606f.
We derive a kinetic Monte Carlo algorithm to simulate flow-induced nucleation in polymer melts. The crystallisation kinetics are modified by both stretching and orientation of the amorphous chains under flow, which is modelled by a recent non-linear tube theory. Rotation of the crystallites under flow is modelled by a simultaneous Brownian dynamics simulation. Our kinetic Monte Carlo approach is highly efficient at simulating nucleation and is tractable even at low under-cooling. The simulations predict enhanced nucleation under both transient and steady state shear. Furthermore the model predicts the growth of shish-like elongated nuclei for sufficiently fast flows, which grow by a purely kinetic mechanism.
我们推导出一种动力学蒙特卡罗算法来模拟聚合物熔体中的流动诱导成核。结晶动力学受到流动下无定形链的拉伸和取向的影响,这可以通过最近的非线性管理论进行建模。在流动下,通过同时进行布朗动力学模拟来模拟晶体的旋转。我们的动力学蒙特卡罗方法在模拟成核方面非常高效,即使在低过冷度下也具有可扩展性。模拟预测了在瞬态和稳态剪切下成核的增强。此外,该模型预测了对于足够快的流动,会出现类晶须状的拉长核的生长,这是通过纯动力学机制进行的。