Theoretical coarse-graining approach to bridge length scales in diblock copolymer liquids.
Theoretical coarse-graining approach to bridge length scales in diblock copolymer liquids.
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二嵌段共聚物液体中桥长度尺度的理论粗粒度方法。
DOI：
10.1103/physreve.76.051801
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发表时间：
2007
期刊：
影响因子：
--
通讯作者：
Marina G. Guenza
中科院分区：
文献类型：
--
作者：
E. Sambriski;Marina G. Guenza
在求解液相积分方程的基础上，建立了粗粒二嵌段共聚物成相互作用软胶体哑铃的微观理论。求解了Ornstein-Zernike方程，在嵌段质量中心水平和聚合物质量中心水平上对二嵌段共聚物体系进行了介观描述。得到了结构对称的二嵌段共聚物液体中嵌段-嵌段、嵌段-单体和质心对的总相关函数的解析形式，它是温度、密度、链长和链组成的函数。该理论正确地预测了温度（chi参数）对热力学驱动的双块体向微畴偏析的影响。粗粒度的描述包含了密度和浓度波动的贡献，随着温度的降低，后者变得主要。给出了块粗粒度总相关函数的数值计算，作为系统与其相变的接近度的函数。在非热状态下进行了与统一原子分子动力学模拟的比较，模拟和理论在定量上一致，不需要可调参数。
A microscopic theory for coarse graining diblock copolymers into dumbbells of interacting soft colloidal particles has been developed based on the solution of liquid-state integral equations. The Ornstein-Zernike equation is solved to provide a mesoscopic description of the diblock copolymer system at the level of block centers of mass, and at the level of polymer centers of mass. Analytical forms of the total correlation functions for block-block, block-monomer, and center-of-mass pairs are obtained for a liquid of structurally symmetric diblock copolymers as a function of temperature, density, chain length, and chain composition. The theory correctly predicts thermodynamically driven segregation of diblocks into microdomains as a function of temperature (chi parameter). The coarse-grained description contains contributions from density and concentration fluctuations, with the latter becoming dominant as temperature decreases. Numerical calculations for the block coarse-grained total correlation functions, as a function of the proximity of the system to its phase transition, are presented. Comparison with united atom molecular dynamics simulations are carried out in the athermal regime, where simulations and theory quantitatively agree with no need of adjustable parameters.