Prof. Kim and Prof. Stone’s team at Princeton University first identified the physico-chemical mixing phenomenon that occurs when two liquids of different surface tension meet. The results of this research were published online on July 31, ‘Nature Physics’, an internationally renowned science journal. In general, it is known that in the case of two liquids that are completely mixed, for example, water and alcohol, mixing and spreading occurs immediately when the two liquids meet. However, the results of this study empirically observed that when the liquids with different surface tension sizes such as alcohol and water were mixed and mixed, the degree of their dependence on time and space was experimentally observed. And propagates along the interface very rapidly.
This research is the result of the idea of ​​the research topic that Prof. Kim conducted in 2012 as a researcher of Prof. Ho-young Kim of Seoul National University. We first performed quantitative analysis by using Particle Image Velocimetry (LIS) technique to show that the mixture of alcohol and water occurred locally in a simplified form at that time. Based on this, we established a theoretical model. This work was published on July 17, 2015 in the American Chemical Society’s “Langmuir”. Since then, Professor Kim has been working as a postdoctoral researcher at Princeton University. He started his own research on the generalization of mixing two different fluids and completed the research at KAIST. When different liquids were mixed, existing studies failed to examine both the micro-mixed structure and the macroscopic mixed structure, and Kim successfully quantified the large and small mixed structures using various flow field visualization techniques.