Department of Chemical Engineering, Centre for Process Systems Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ, United Kingdom.
Department of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08544, USA.
J Chem Phys. 2014 Feb 7;140(5):054909. doi: 10.1063/1.4863331.
In this contribution, we develop a coarse-graining methodology for mapping specific block copolymer systems to bead-spring particle-based models. We map the constituent Kuhn segments to Lennard-Jones particles, and establish a semi-empirical correlation between the experimentally determined Flory-Huggins parameter χ and the interaction of the model potential. For these purposes, we have performed an extensive set of isobaric-isothermal Monte Carlo simulations of binary mixtures of Lennard-Jones particles with the same size but with asymmetric energetic parameters. The phase behavior of these monomeric mixtures is then extended to chains with finite sizes through theoretical considerations. Such a top-down coarse-graining approach is important from a computational point of view, since many characteristic features of block copolymer systems are on time and length scales which are still inaccessible through fully atomistic simulations. We demonstrate the applicability of our method for generating parameters by reproducing the morphology diagram of a specific diblock copolymer, namely, poly(styrene-b-methyl methacrylate), which has been extensively studied in experiments.
在本研究中，我们开发了一种粗粒化方法，将特定嵌段共聚物体系映射到基于珠子-弹簧粒子的模型。我们将组成的 Kuhn 段映射到 Lennard-Jones 粒子，并建立了实验确定的 Flory-Huggins 参数 χ 与模型势能相互作用之间的半经验相关性。为此，我们对具有相同大小但具有不对称能量参数的 Lennard-Jones 粒子的二元混合物进行了广泛的等压-等温蒙特卡罗模拟。然后，通过理论考虑将这些单体混合物的相行为扩展到具有有限大小的链。从计算的角度来看，这种自上而下的粗粒化方法很重要，因为嵌段共聚物系统的许多特征都处于时间和长度尺度上，这些尺度仍然无法通过全原子模拟来实现。我们通过重现特定嵌段共聚物（即聚（苯乙烯-b-甲基丙烯酸甲酯））的形态图来证明我们生成参数的方法的适用性，该嵌段共聚物在实验中得到了广泛研究。
