Sethuraman Vaidyanathan, Nguyen Bryan H, Ganesan Venkat
Department of Chemical Engineering, University of Texas at Austin, Austin, Texas 78712, USA.
J Chem Phys. 2014 Dec 28;141(24):244904. doi: 10.1063/1.4904390.
We investigate the mapping required between the interaction parameters of two different coarse-grained simulation models to ensure a match of the long-range structural characteristics of multicomponent polymeric system. The basis for our studies is the recent work of Morse and workers, which demonstrated the existence of a mapping between the interaction parameters of different coarse-grained simulation models which allow for a matching of the peak of the disordered state structure factor in symmetric diblock copolymers. We investigate the extensibility of their results to other polymeric systems by studying a variety of systems, including, asymmetric diblock copolymers, symmetric triblock copolymers, and diblock copolymer-solvent mixtures. By using the mapping deduced in the context of symmetric diblock copolymers, we observe excellent agreement for peak in the inverse structure between both two popular coarse grained models for all sets of polymeric melt systems investigated, thus showing that the mapping function proposed for diblock copolymer melts is transferable to other polymer melts irrespective of the blockiness or overall composition. Interestingly, for the limited parameter range of polymer-solvent systems investigated in this article, the mapping functions developed for polymer melts are shown to be equally effective in mapping the structure factor of the coarse-grained simulation models. We use our findings to propose a methodology to create ordered morphologies in simulations involving hard repulsive potentials in a computationally efficient manner. We demonstrate the outcomes of methodology by creating lamellar and cylindrical phases of diblock copolymers of long chains in the popularly used Kremer-Grest simulation model.
我们研究了两种不同粗粒化模拟模型的相互作用参数之间所需的映射关系，以确保多组分聚合物体系的长程结构特征相匹配。我们研究的基础是莫尔斯及其同事最近的工作，该工作证明了不同粗粒化模拟模型的相互作用参数之间存在一种映射关系，这种映射关系能使对称二嵌段共聚物中无序态结构因子的峰值相匹配。我们通过研究多种体系，包括不对称二嵌段共聚物、对称三嵌段共聚物和二嵌段共聚物 - 溶剂混合物，来探究他们的结果对其他聚合物体系的可扩展性。通过使用在对称二嵌段共聚物背景下推导的映射关系，我们观察到，在所研究的所有聚合物熔体体系中，两种常用的粗粒化模型在反结构中的峰值都有很好的一致性，这表明为二嵌段共聚物熔体提出的映射函数可转移到其他聚合物熔体，而与嵌段性或总体组成无关。有趣的是，对于本文所研究的聚合物 - 溶剂体系的有限参数范围，为聚合物熔体开发的映射函数在映射粗粒化模拟模型的结构因子方面同样有效。我们利用研究结果提出了一种方法，以便在涉及硬排斥势的模拟中以计算高效的方式创建有序形态。我们通过在常用的克雷默 - 格雷斯特模拟模型中创建长链二嵌段共聚物的层状和柱状相来展示该方法的结果。
