Department of Physics, Graduate School of Science
Division of Physics, Faculty of Science
Imagine introducing a droplet of red liquid into a container of water.
You may believe that the red droplet will expand, and its color will become diluted, and you would be correct,
if the droplet is not an ionic liquid. Ionic liquids are composed of cation and anion and have very low melting temperatures.
Recently, we discovered a new type of mixing process in an ionic liquid and water system. Dispersion of ionic liquids does not obey the usual diffusion equation.
A droplet of ionic liquid has a sharp interface in water despite the miscibility of the droplet to water. This observation can not be explained by conventional theories.
It is known that some kind of cells aggregate as a survival strategy when they are starved.
You can see beautiful network patterns in their aggregation process. We proposed a very simple model for the aggregation dynamics and successfully reproduced the network patterns in numerical simulations.
Because this model is constructed with a minimal number of factors, it is expected that the model can be applied to other systems that exhibit radial network patterns.
Soft matters are so sensitive to external stresses that even very weak stress like thermal fluctuations can deform them.
Temperature gradients, therefore, strongly affect the dynamics of soft matters.
We investigate the effect of temperature gradient on soft matter systems such as Rayleigh-Benard convections of gels and membrane systems of surfactants.
Investigation of the effects of temperature gradients is important not only for basic research,
but also for applications, as the temperature distribution is always heterogeneous in natural environments and practical situations.