Study on flow-indueed structure and instability of surfactant aqueous solution by measuring microscopic distribution of flow birefringence

本研究是对表面活性剂作为工质的水性流动特性的研究。我们从微观的角度考虑了胶束在流动过程中的结构变化。大阪大学的四方教授报告说，蠕虫状的胶束不仅纠缠在一起，而且还相互穿过。由于我们认为胶束的排列比聚合物细丝更强，因此我们通过流动双折射测量了胶束的排列状态。在此基础上，建立了一种双折射分布显微镜计量方法，能够在几十μm的尺度上测量流体双折射的分布，并通过光学显微镜的阶数分辨率来测量从形成条带等织构结构的胶束变化到不稳定流动的产生过程。用光学显微镜观察了表面活性剂CTAB/ nose溶液在间隙为0.5 mm ~ 2.0mm的平行板流池中的流动行为。为了使启动流量恒定，使用了注射泵。流动显示观察到，当流量超过一定值时，流动池内的所有样品在流动开始后立即变得不透明。在这种情况下，剪切应力和应变均匀地作用于流动池中的样品，然后剪切诱导上下板附近形成两个不透明的薄层。一段时间后，在入口区域形成与气流方向正交的白色带状区域。这个带区也是胶束的结构变化，但它是由储层的伸长变形产生的。该带区的不均匀性导致了流动的不稳定性。完成了可同时测量16个不同位置流量双折射的仪器。利用该仪器，测量了流动池内流动双折射分布的启动行为。少

This research is an investigation of flow property of surfactant aqueous to use as working fluid. We introduced a microscopic point of view into this research with considering the flow-induced structure change of micelles. Prof.Shikata, Osaka University, reported that the wormlike micelles are not only entangled but they are passing through each other. Since we thought that the micelles aligned stronger than polymer filaments by this concept, we measured the state of alignment of micelles by flow birefringence. Moreover, we aimed to develop the birefringence distribution microscope metrology that was able to measure the distribution of the flow birefringence from several μm at tens of μm intervals, and to measure the process from the change in the micelle that formed the texture structure such as banding to the generation of unstable flow by the resolution of the optical microscope order. The flow behavior of a surfactant solution, CTAB/NaSal, in parallel plates flow cell which has 0.5 … More mm to 2.0mm in gap was observed by using optical microscope. To make start-up flow with a constant flow rate, a syringe pump was used. It was observed by the flow visualization that all sample in the flow cell becomes opaque immediately after beginning of flow when the flow rate exceeds a certain value. In this case, the shear stress and strain applied homogeneously to the sample in the flow cell and then the shear induced two opaque thin layers formed near the upper and lower plates. After a while, a white band area which is orthogonal to the flow direction is formed on the entrance region. This band area is also the micelle's structure change but it is generated by elongation deformation in reservoir. The nonuniformity of this band area causes instability of flow. The instrument which can measure the flow birefringence at different 16 positions simultaneously was completed. By using this instrument, the start-up behavior of the distribution of the flow birefringence in the flow cell was measured. Less