基于相场模型的聚合物单晶模拟形态景观

Simulated morphological landscape of polymer single crystals by phase field model.

作者信息

Wang Dong, Shi Tongfei, Chen Jizhong, An Lijia, Jia Yuxi

机构信息

State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China.

出版信息

J Chem Phys. 2008 Nov 21;129(19):194903. doi: 10.1063/1.2985652.

DOI:10.1063/1.2985652

PMID:19026085

Abstract

The novel phase field model with the "polymer characteristic" was established based on a nonconserved spatiotemporal Ginzburg-Landau equation (TDGL model A). Especially, we relate the diffusion equation with the crystal growth faces of polymer single crystals. Namely, the diffusion equations are discretized according to the diffusion coefficient of every lattice site in various crystal growth faces and the shape of lattice is selected based on the real proportion of the unit cell dimensions. Spatiotemporal growth of syndiotactic polypropylene single crystals during isothermal crystallization has been investigated theoretically based on this phase field model. Two dimensional numerical calculations are performed to elucidate the faceted single crystal growth including square, rectangular, lozenge-shaped, and hexagonal single crystals. Our simulated patterns are in good agreement with the experimental morphologies, and the physical origin of polymer single crystal growth is discussed.

摘要

基于非守恒时空金兹堡-朗道方程（TDGL模型A）建立了具有“聚合物特性”的新型相场模型。特别地，我们将扩散方程与聚合物单晶的晶体生长面联系起来。也就是说，根据不同晶体生长面中每个晶格点的扩散系数对扩散方程进行离散化，并根据晶胞尺寸的实际比例选择晶格形状。基于该相场模型，从理论上研究了间规聚丙烯单晶在等温结晶过程中的时空生长。进行了二维数值计算，以阐明包括方形、矩形、菱形和六边形单晶在内的多面单晶生长。我们模拟的图案与实验形态吻合良好，并对聚合物单晶生长的物理起源进行了讨论。