Pham Tri Thanh, Bajaj Mohit, Prakash J Ravi
Department of Chemical Engineering, Monash University, VIC-3800, Australia.
Soft Matter. 2008 May 14;4(6):1196-1207. doi: 10.1039/b717350d.
The effect of solvent on the collapse dynamics of homopolymers is investigated with Brownian dynamics simulations of a non-linear bead-spring chain model incorporating implicit hydrodynamic interactions. Our simulations suggest that the polymer collapse takes place via a three-stage mechanism, namely, formation of pearls, coarsening of pearls and the formation of a compact globule. The collapse pathways from a good solvent state to a poor solvent state are found to be independent of hydrodynamic interactions. On the other hand, hydrodynamic interaction is found to speed up the collapse rate. At a large quench depth (the depth of the Lennard-Jones potential), independent of the presence of hydrodynamic interaction, polymer molecules are found to be trapped in metastable states for long periods before acquiring their native globular state. The exponents characterizing the decay of various properties such as the radius of gyration are determined and compared with the values reported in the literature.
通过包含隐式流体动力学相互作用的非线性珠-弹簧链模型的布朗动力学模拟，研究了溶剂对均聚物塌缩动力学的影响。我们的模拟表明，聚合物塌缩通过三阶段机制发生，即珍珠的形成、珍珠的粗化以及紧密球状体的形成。发现从良溶剂状态到不良溶剂状态的塌缩路径与流体动力学相互作用无关。另一方面，发现流体动力学相互作用会加快塌缩速率。在较大的淬火深度（ Lennard-Jones 势的深度）下，无论流体动力学相互作用是否存在，聚合物分子在获得其天然球状状态之前都会长时间被困在亚稳态。确定了表征诸如回转半径等各种性质衰减的指数，并与文献报道的值进行了比较。
