HORN facilitated research exchanges between Curtin University, Perth, Western Australia, and the University of Hyogo, Himeji, Hyogo, Japan. During my one-month stay, I gave lectures at the university, communicated with students, and conducted experiments on functional development of surfactants.

A small amount of useful resources contained in minerals is separated into only valuable resources by using various surfactants after dispersing the minerals in water, but the loss is very large. Therefore, by designing a new chemical structure of surfactants, it may be possible to very efficiently recover trace amounts of useful resources from minerals. The goal of this research application is to synthesize and characterize zwitterionic surfactants. In the future, the technology obtained will be linked to the recovery of useful substances from minerals. I have measured changes in the surface tension of surfactants over time and performed simulations using a theoretical surface tension prediction model.

Ionic surfactants are an important class of reagents that are used in many industrial processes. The macro properties of surfactants are determined by their amphiphilic nature. Yet, the molecular interaction at the surface remains unclear. Recently, we developed a new method to study the surfactant layer under electrostatic field. The results showed that the surfactant-generated tension decreased linearly with the strength of electrostatic field. The experimental observation was also confirmed by molecular simulations. More importantly, the simulation revealed the molecular nature of the interaction. In contrast to conventional notation, the electrical field did not separate counter-ion from surfactant head. Instead, the water arrangement around surfactant and counter-ion was re-arranged. The result confirms the role of water arrangement in surfactant adsorption. The new insights provide an important foundation to predict the surfactant behavior at the air/water surface.