Temporal Shear Oscillation in Steady Shear Flow of CTAB/NaSal Wormlike Micellar Solutions
Temporal Shear Oscillation in Steady Shear Flow of CTAB/NaSal Wormlike Micellar Solutions
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CTAB/NaSal 蠕虫状胶束溶液稳定剪切流中的时间剪切振荡
DOI：
10.1678/rheology.43.39
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
Tsutomu Takahashi
中科院分区：
文献类型：
--
作者：
Masatoshi Ito;Y. Yoshitake;Tsutomu Takahashi
对蠕虫状胶束溶液的时间剪切应力振荡现象的发生条件进行了实验研究。检查具有不同表面活性剂和盐浓度但具有相同弛豫时间的两个样品。富盐样品形成网状胶束结构，不表现出时间剪切应力振荡，但形成蠕虫状胶束的另一样品表现出应力振荡现象。该样品的流动曲线中有一个应力平台区域，并且应力振荡现象发生在该平台区域的较高剪切速率区域。该剪切速率状态与剪切诱导结构（SIS）生成状态一致，并且在该现象中在内壁和外壁附近测量的流动双折射显示出不同的值。这种现象不是由二次流或涡度方向的剪切带引起的，而是与速度梯度剪切带和SIS的产生密切相关。
The occurrence condition of a temporal shear stress oscillation phenomenon of wormlike micellar solutions is experimentally investigated. The two samples that have different surfactant and salt concentrations but have a same relaxation time are examined. The salt rich sample forms network micelles structure and does not exhibit the temporal shear stress oscillation, but the other sample that forms wormlike micelles shows the stress oscillation phenomenon. This sample has a stress plateau region in its flow curve and the stress oscillation phenomenon occurs in the higher shear rate regime of this plateau region. This shear rate regime coincides with the shear-induced structure (SIS) generation regime, and the flow birefringence measured near the inner and outer wall shows different value at the phenomenon. The phenomenon is not caused by secondary flow or shear-banding to the vorticity direction but it is closely related with the generation of the velocity gradient shear-banding and the SIS.