Buckling instabilities in dilute polymer solution elastic strands
Buckling instabilities in dilute polymer solution elastic strands
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DOI：
10.1007/s00397-010-0467-4
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发表时间：
2010-12-01
期刊：
影响因子：
2.3
通讯作者：
Haward, Simon J.
中科院分区：
文献类型：
--
作者：
Haward, Simon J.
一个微流控振荡交叉槽流是用来可视化的双折射链在稀聚苯乙烯溶液中具有高的时间分辨率，特别是专注于在流动方向上的逆转。由于聚合物构象滞后，弹性股线缓慢松弛并表现出压缩模量，导致“屈曲不稳定性”。“一个双折射的弹性环形成在十字架的出口通道中，在垂直方向上播种新的双折射链的发展。这些观察结果与聚合物溶液的循环流动（例如，存在滞流点的多孔介质流动），并用于这种流动的可伸缩非线性弹性哑铃模型。
A microfluidic oscillatory cross-slot flow is used to visualize birefringent strands in dilute polystyrene solutions with high temporal resolution, focusing specifically on reversals in the flow direction. Due to polymer conformation hysteresis, the elastic strands are slow to relax and demonstrate a compressive modulus, resulting in a "buckling instability." An elastic loop of birefringence forms in an exit channel of the cross, seeding the development of a new birefringent strand in the perpendicular direction. These observations have major relevance to cyclic flows of polymer solutions (e.g., porous media flows where stagnation points are present) and for finitely extensible nonlinear elastic dumbbell modeling of such flows.