Song Kai-Xu, Jia Yu-Xi, Sun Zhao-Yan, An Li-Jia
State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, People's Republic of China.
J Chem Phys. 2008 Oct 14;129(14):144901. doi: 10.1063/1.2981804.
By incorporating self-consistent field theory with lattice Boltzmann method, a model for polymer melts is proposed. Compared with models based on Ginzburg-Landau free energy, our model does not employ phenomenological free energies to describe systems and can consider the chain topological details of polymers. We use this model to study the effects of hydrodynamic interactions on the dynamics of microphase separation for block copolymers. In the early stage of phase separation, an exponential growth predicted by Cahn-Hilliard treatment is found. Simulation results also show that the effect of hydrodynamic interactions can be neglected in the early stage. For the late stage of phase separation, it is easy to see the effects of hydrodynamic interactions on the ordering process of lamellae phase. From the analysis of structure factor curves, we find that the growth of domains is faster if hydrodynamic interactions are introduced. Furthermore, the scaling of the pattern dynamics is investigated for the late stage at zero thermal noise. By studying the behavior of scaling exponents of the structure factor and the nematic order-parameter correlation function C(nn), we can see that the effects of hydrodynamic interactions lead to bigger growth exponent for both functions.
通过将自洽场理论与格子玻尔兹曼方法相结合，提出了一种聚合物熔体模型。与基于金兹堡 - 朗道自由能的模型相比，我们的模型不采用唯象自由能来描述系统，并且能够考虑聚合物的链拓扑细节。我们使用该模型研究流体动力学相互作用对嵌段共聚物微相分离动力学的影响。在相分离的早期阶段，发现了由卡恩 - 希利厄德处理预测的指数增长。模拟结果还表明，在早期阶段流体动力学相互作用的影响可以忽略不计。对于相分离的后期阶段，很容易看出流体动力学相互作用对片层相有序过程的影响。通过对结构因子曲线的分析，我们发现引入流体动力学相互作用时，畴的生长更快。此外，研究了在零热噪声下后期阶段图案动力学的标度。通过研究结构因子和向列序参量相关函数(C(nn))的标度指数行为，我们可以看到流体动力学相互作用的影响导致这两个函数都有更大的生长指数。
