论文部分内容阅读
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,并在剪切松弛模量较大的情况下,不规则相结构的缓慢松弛导致了剪切应力在相分离后期长期存在.
The GPU-accelerated 3D viscoelastic model was used to simulate the three-dimensional numerical simulation of the viscoelastic model. The phase-separation morphology and phase separation kinetics of the medium-concentration polymer solution were systematically studied. The simulation results show that the asymmetry of the bulk stress is the important reason for the phase inversion. The experimentally observed reversal of the evolution of the polymer solution is consistent with the fact that the polymer-rich phase forms the network structure first, and then the polymer network shrinks and breaks off and eventually becomes a discrete droplet phase.The bulk relaxation modulus increases, on the one hand The inhibition of the concentration fluctuation in the initial stage of phase separation led to the delay of the phase inversion reaction, and on the other hand, it facilitated the formation of large polymer-enriched droplet phase and accelerated phase region growth in the late phase separation. The increase of the shear relaxation modulus was only Which helps the polymer-rich phase to maintain the network structure. When the shear relaxation modulus is large, the slow relaxation of the irregular phase structure leads to the long-term existence of the shear stress in the late phase separation.