PHASE INVERSION DURING VISCOELASTIC PHASE SEPARATION : ROLES OF BULK AND SHEAR RELAXATION MODULI
PHASE INVERSION DURING VISCOELASTIC PHASE SEPARATION : ROLES OF BULK AND SHEAR RELAXATION MODULI
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DOI：
10.1103/physrevlett.78.4966
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发表时间：
1997-06
影响因子：
8.6
通讯作者：
Hajime Tanaka;Takeaki Araki
中科院分区：
文献类型：
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作者：
Hajime Tanaka;Takeaki Araki
我们通过数值求解“粘弹性模型”的朗之万方程来模拟聚合物溶液的粘弹性相分离，该模型除了剪切松弛模量之外还新包含了体积松弛模量。结果再现了实验观察到的粘弹性相分离的几乎所有基本特征：（i）冻结期的存在，富溶剂相的成核，（ii）富聚合物相的体积收缩，（iii）网络状结构的瞬时形成，以及（iv）最后阶段的相转化。我们的模拟清楚地表明，体积应力导致 (i)、(ii) 和 (iv)，而剪切应力则导致 (iii)。 [S0031-9007(97)03404-2]
We simulate viscoelastic phase separation of polymer solutions by solving numerically Langevin equations of a “viscoelastic model” that newly includes the bulk relaxation modulus in addition to the shear relaxation modulus. The results reproduce almost all the essential features of viscoelastic phase separation observed experimentally: (i) The existence of a frozen period, the nucleation of the solvent-rich phase, (ii) the volume shrinking of the polymer-rich phase, (iii) the transient formation of a networklike structure, and (iv) the phase inversion in the final stage. Our simulations clearly indicate that the bulk stress is responsible for (i), (ii), and (iv), while the shear stress for (iii). [S0031-9007(97)03404-2]