Water is fundamental to the existence of life. Many biological processes take place in crowded aqueous surroundings, and water in living cells can be considered as confined water. Confining water at nanoscale behaves differently to those in the bulk with respect to the crystallization, nucleation, and molecular dynamics. While in biological systems, the role of confined water is of crucial importance, but still far from fully understood.

Prof. Yao will discuss the state of water in a soft confining media provided by lipidic mesophase. Yao and his colleagues applied an unfrozen lipid, phytantriol, to form a stable lamellar phase at subzero temperatures. By combining differential scanning calorimetry and dielectric spectroscopy, they were able to understand crystallization and the dynamics of water in such soft confinement. At lower hydration (<9.5 wt% of water), the nanoconfined water remains in a liquid state down to -120 °C. But the phase structure of lipidic mesophase varies depending on the water content and the temperature of the system. Another interesting question he addresses is the state of water during phase transitions. Yao combined Fourier transform infrared spectroscopy and dielectric radiation spectroscopy to explore both the static and dynamic states of water network during the phase transition from bicontinuous cubic phases to a reverse hexagonal phase and reverse micellar phases.