Efficient continuum model for simulating polymer blends and copolymers
Efficient continuum model for simulating polymer blends and copolymers
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DOI：
10.1063/1.472978
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发表时间：
1996-12-15
影响因子：
4.4
通讯作者：
Gupta, AM
中科院分区：
文献类型：
--
作者：
Grest, GS;Lacasse, MD;Gupta, AM
提出了一种有效的模拟聚合物共混物和共聚物的连续介质模型。在这个模型中，相互作用是短程的和纯排斥的，因此允许出色的计算性能。相分离的驱动力是相似和不相似聚体之间的排斥相互作用强度的差异。该模型基本上由一个分子动力学算法，辅以适当的蒙特卡罗交换过程。为了证明该模型的有效性，我们研究了两个系统，一个对称的二元共混物的聚合物和一个对称的二嵌段共聚物系统。对于二元共混物，我们确定的相图，并发现，如理论预测的那样，临界相互作用参数的规模与聚合物的链长的倒数。对于两嵌段共聚物体系，我们研究了单相区和微相分离的层状区。对于后者，我们表明，恒压算法是更合适的，因为，与最近的晶格模拟，片层间距可以自我调整，在这样的合奏。(C)1996年美国物理学会。
An efficient continuum model for simulating polymer blends and copolymers is presented. In this model, the interactions are short-range and purely repulsive, thus allowing for excellent computational performances. The driving force for phase separation is a difference in the repulsive interaction strength between like and unlike mers. The model consists essentially of a molecular-dynamics algorithm, supplemented by an appropriate Monte Carlo exchange process. To demonstrate the effectiveness of the model we study two systems, a symmetric binary blend of polymers and a symmetric diblock copolymer system. For the binary blend, we determine the phase diagram and find, as predicted by theory, that the critical interaction parameter scales with the inverse of the chain length of the polymers. For the diblock copolymer system, we study both the one-phase region and the microphase separated lamellar region. For the latter, we show that constant-pressure algorithms are more appropriate since, contrary to recent lattice simulations, the lamellar spacing can self-adjust in such an ensemble. (C) 1996 American Institute of Physics.