中文摘要：

利用GPU加速技术实现黏弹模型的三维数值模拟，系统研究了中等浓度聚合物溶液的分相形貌和相分离动力学．模拟结果表明本体应力的不对称是体系出现相反转的重要原因．与实验观察的聚合物溶液相反转的演化过程一致，首先聚合物富集相形成网络结构，然后聚合物网络收缩断网，最后变为离散的液滴相．本体松弛模量的增加，一方面会抑制相分离初期的浓度涨落，导致相反转发生时间延迟；另一方面在相分离后期有助于形成大的聚合物富集液滴相，加速相区增长．剪切松弛模量的增加只有助于聚合物富集相保持网络结构，并在剪切松弛模骨较大的情况下．不规则相结构的缪悔松弛导剪了前切席力存相分离后期长期存存．

英文摘要：

The morphology and dynamics of viscoelastic phase separation in polymer solutions are investigated by the use of a graphic process unit （GPU） accelerated three-dimensional numerical simulation of a viscoelastic model for the first time. The results show the bulk stress is a prerequisite to the phase inversion. In agreement with the phase inversion observed in previous experiments, the polymer rich domain first forms a continuous network structure and then shrinks and inverts to a dispersed droplet structure. Interestingly, the growth of the bulk relaxation modulus suppresses the concentration fluctuation in the early stage of phase separation,and the phase inversion is thus delayed by the increase of bulk relaxation modulus. On the other hand, the growth of the bulk relaxation modulus increases the domain growth rate in the late stage of phase separation and leads to larger-sized polymer rich domains. Additionally, the growth of the shear relaxation modulus can help polymer rich domains to maintain network-like structures, and in the case of a larger shear relaxation modulus,the shear stress can exist for a longer time due to the slow relaxation of irregular polymer- rich domains in the late stage of phase separation.