非均相聚合物流体的粘弹性介观模型及其相分离研究

粘弹性引起的动力学不对称性是聚合物在相分离过程中形成特殊形貌的重要原因之一。本项目拟结合聚合物场论和Doi双流体模型，在介观层次上建立聚合物粘弹性模型，并结合有限差分方法、格子Boltzmann方法和谱方法等多种数值方法，发展能适用于复杂流体相行为研究且高效而稳定的模拟方法，用于模拟均聚物共混体系的相分离和共聚物体系的微相分离等过程。通过本项目的实施，以期重现实验中观察到的特殊形貌和现象，并掌握粘弹性影响聚合物相分离的普适性规律。

Dynamic asymmetry between two components of mixture plays a crucial role in formation of special morphologies in phase separation of polymeric fluids. Here, we propose to build a mesoscopic model of polymeric viscoelasticity, which is based on the polymeric field-theoretic method and Doi's two-fluid model. A hybrid numerical strategy, which couples finite different method, lattice Boltzmann method, and spectral method, will be developed to sovle the model equations. This project aims at a highly efficient and numerically stabe simulation method for viscoelastic phase separation of complex fluids. Our new method will ultimately be applied for phase separation of homopolymer mixure and microphase separation of block copolymers to reproduce the special morphologies and phenomenon in experiment observation of visoelascity phase separation,and to unravel the universal mechanisms of viscoelastic phase separation in polymeric fluids.