Professor Heon-Sang Lee's team identifies a fully miscible fluid interface mechanism

Professor Heon-Sang Lee's research team in the Department of Chemical Engineering derived the principle of 'co-evolution'

(Busan = Yonhap News) Reporter Min Young-gyu = Dong-A University announced on the 28th that Professor Lee Heon-sang's research team in the Department of Chemical Engineering succeeded in deriving the 'free energy co-evolution variation principle' that explains the creation, continuation, and collapse mechanisms of long-maintained interfaces (boundaries) in completely miscible fluids in a single framework, and to quantitatively predict the lifespan of the interface.

The phenomenon of completely miscible fluids coming into contact is commonly observed throughout natural and technological systems, including inside living cells, the human body, industrial chemical processes, and the marine environment.

However, the specific physical principle of maintaining an interface for a certain period of time without mixing immediately after contact with fluids has remained an unresolved problem for over 130 years since the publication of JD van der Waals's interface theory in 1893.

Professor Lee's research team solved the difficult problem using the principles of dual pairing and self-consistent co-evolution of 'free energy terrain' and 'interface concentration field'.

The existing theory approached it in a sequential manner, where a given topography determines the flow of water or the water flow first changes the topography and the change affects the flow again, but Professor Lee's research team changed the idea to a co-evolution principle in which the topography and water flow form one state and change together at the same time.

Using this, the research team linked the entire process from creation and continuation of the interface, thickening, and final collapse into a single theoretical framework, and quantitatively predicted the life of the interface even in fluids with completely different chemical properties.

The paper containing this achievement was published in the international academic journal 'Communications Physics' on the 23rd.