Flory-Huggins parameter χ, from binary mixtures of Lennard-Jones particles to block copolymer melts
Flory-Huggins parameter χ, from binary mixtures of Lennard-Jones particles to block copolymer melts
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DOI：
10.1063/1.4863331
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发表时间：
2014-02-07
影响因子：
4.4
通讯作者：
Panagiotopoulos, Athanassios Z.
中科院分区：
文献类型：
--
作者：
Chremos, Alexandros;Nikoubashman, Arash;Panagiotopoulos, Athanassios Z.
在这篇文章中，我们开发了一种粗粒度方法，用于将特定的嵌段共聚物系统映射到基于珠弹簧颗粒的模型。我们将组成的库恩段映射到伦纳德-琼斯粒子，并在实验确定的弗洛里-哈金斯参数 chi 与模型势的相互作用之间建立半经验相关性。为此，我们对具有相同尺寸但具有不对称能量参数的 Lennard-Jones 粒子的二元混合物进行了一系列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尺寸的链。从计算的角度来看，这种自上而下的粗粒度方法很重要，因为嵌段共聚物系统的许多特征是在时间和长度尺度上的，而通过完全原子模拟仍然无法获得这些特征。我们通过重现特定二嵌段共聚物（即聚（苯乙烯-b-甲基丙烯酸甲酯））的形态图来证明我们的参数生成方法的适用性，该共聚物已在实验中得到广泛研究。 (C) 2014 AIP 出版有限责任公司。
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 chi 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. (C) 2014 AIP Publishing LLC.