Title : Physics and Chemistry of Water Microdroplets
일시 : 2023년 11월 28일(화), 17시
Speaker : 이재규 (서울대)
Abstract : This talk will present the unique properties of physico-chemical reactions in water microdroplets. We found that molecules are in highly ordered states near the microdroplet interface. This lowered entropic barrier allows thermodynamically unfavorable reactions, such as phosphorylation and RNA formation, to proceed without any enzyme or ATP energy source at room temperature in water microdroplets. The FRET analysis revealed that molecules are highly localized at the nanoscale regime near the water surface. The enhanced and aligned collisions between molecules lead to the accelerations of various reactions, including protein unfolding, redox reactions, hydrogen-deuterium exchange, and crystallization. Besides, the charge exchange between water and solute molecules spontaneously occurs at the water interface, leading to the oxidation of water molecules and the reduction of solute molecules. Vibrational Stark spectroscopy coupled with stimulated Raman excited fluorescence microscopy showed the presence of a strong intrinsic interfacial electric field formed at the surface of the microdroplet. This strong electric field, combined with the partial desolvation effect, can be responsible for the unusual behaviors of biomolecules at the aqueous-nonaqueous interface. This talk will also describe the physics and chemistry of the cellular condensate interface as well as the application of microdroplet chemistry to various energy, environmental, and biomedical research fields.