Quantitative description of the non-linear flow properties of viscoelastic surfactant solutions
Quantitative description of the non-linear flow properties of viscoelastic surfactant solutions
复制标题
粘弹性表面活性剂溶液非线性流动特性的定量描述
DOI：
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发表时间：
1995
期刊：
影响因子：
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通讯作者：
H. Rehage
中科院分区：
文献类型：
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作者：
P. Fischer;H. Rehage
我们系统地研究了某些粘弹性表面活性剂溶液的非线性流动特性。虽然这些系统的动态特征可以通过改进的蠕动理论来描述，但可以在启动流动实验中获得大速度梯度应力超调状态，并在稳态状态下获得剪切稀化特性。粘弹性表面活性剂溶液的这些性质可以用 Giesekus 首先提出的非线性麦克斯韦材料来描述。从这些模型中，很容易计算剪切粘度 η(∞, (dot gamma)) 和第一法向应力系数 ω 1 (∞, (dot gamma)) 的稳态值。人们经常观察到这些属性服从粘度函数，例如 Yamamoto 关系和 Gliesle 镜像关系。事实证明，实验结果与单模 Giesekus 模型的理论预测相当吻合，特别是通过调整唯一的自由参数 α=0.5。对于这些条件，Cox-Merz 规则、Yamamoto 关系和两个 Gleisle 镜像关系都会自动从理论模型导出。非常有趣的是，非线性麦克斯韦材料可以用于粘弹性表面活性剂溶液的非线性流动性质的定性描述，例如第一法向应力差的剪切粘度。
We have systematically studied the non-linear flow properties of certain viscoelastic surfactant solutions. While the dynamic features of these systems can be described by a modified reptation theory, one obtains in the regime of large velocity gradient stress overshoot in start-up flow experiments and shear thinning properties in the steady-state regime. These properties of viscoelastic surfactant solutions can be described with a non-linear Maxwell material, first proposed by Giesekus. From these models it is easy to calculate steady-state values of the shear viscosity η(∞, (dot gamma)) and the first normal stress coefficient ω 1 (∞, (dot gamma)). It is often observed that these properties obey viscometric functions such as the Yamamoto relation and the Gliesle mirror relationships. It turns out that the experimental results are in fairly good agreement with theoretical predictions of the one-mode Giesekus model, especially by adjusting the only free parameter with α=0.5. For these conditions, the Cox-Merz rule, the Yamamoto relation, and both Gleisle mirror relations are automatically derived from the theoretical model. It is very interesting that the non-linear Maxwell material can be used for the qualitative description of non-linear flow properties of viscoelastic surfactant solutions, such as the shear viscosity of the first normal stress difference.