Kobe University Tenure-Track Researchers
Research field : Dilute Solution Rheology, Complex fluids
Polymers are a famous "soft matter". An important feature of soft matter is the huge size of each molecule. This causes interactions within the molecule and with surrounding solvents. Because of these interactions, fluids containing soft matters such as polymers induce complex fluidity, and are called complex fluids. My research interest is in the hierarchic structures of complex fluids. Complex fluids such as polymer solutions show interesting phenomena in each scale. For example, in a macro-scale a polymer solution reduces frictional drag; therefore fluids containing polymers flow smoothly. This phenomenon is called drag reduction. Since drag reduction is useful to reduce energy when transferring fluids, this technique is used in many industrial applications. On the other hand, in a micro-scale, the same polymer solution induces unstable flows, which is called elastic instability. In order to produce high-quality products in the micro-scale, elastic instability should be avoided. I consider all these phenomena to be related to the extensional viscosity of polymers. Therefore, I have also tried to develop an extensional viscometer to measure the extensional rheology of dilute polymer solutions.