Lugo-Frías Rodrigo, Klapp Sabine H L
Institute für Theoretische Physik, Technische Universität Berlin, Hardenbergstrasse 36, 10623 Berlin, Germany.
J Phys Condens Matter. 2016 Jun 22;28(24):244022. doi: 10.1088/0953-8984/28/24/244022. Epub 2016 Apr 26.
This paper is concerned with the dynamics of a binary mixture of rod-like, repulsive colloidal particles driven out of equilibrium by means of a steady shear flow (Couette geometry). To this end we first derive, starting from a microscopic density functional in Parsons-Lee approximation, a mesoscopic free energy functional whose main variables are the orientational order parameter tensors. Based on this mesoscopic functional we then explore the stability of isotropic and nematic equilibrium phases in terms of composition and rod lengths. Second, by combining the equilibrium theory with the Doi-Hess approach for the order parameter dynamics under shear, we investigate the orientational dynamics of binary mixtures for a range of shear rates and coupling parameters. We find a variety of dynamical states, including synchronized oscillatory states of the two components, but also symmetry breaking behavior where the components display different in-plane oscillatory states.
本文关注的是通过稳定剪切流（库埃特几何结构）驱动至非平衡态的棒状排斥性胶体粒子二元混合物的动力学。为此，我们首先从帕森斯 - 李近似下的微观密度泛函出发，推导出一个介观自由能泛函，其主要变量是取向序参量张量。基于这个介观泛函，我们接着从组成和棒长方面探究各向同性和向列相平衡相的稳定性。其次，通过将平衡理论与用于剪切下序参量动力学的多伊 - 赫斯方法相结合，我们研究了一系列剪切速率和耦合参数下二元混合物的取向动力学。我们发现了多种动力学状态，包括两种组分的同步振荡状态，还有组分呈现不同面内振荡状态的对称性破缺行为。
