title: Vitrification and levitation of a liquid droplet on liquid nitrogen.
abstract: The vitrification of a liquid occurs when ice crystal formation is prevented in the cryogenic environment through ultrarapid cooling. In general, vitrification entails a large temperature difference between the liquid and its surrounding medium. In our droplet vitrification experiments, we observed that such vitrification events are accompanied by a Leidenfrost phenomenon, which impedes the heat transfer to cool the liquid, when the liquid droplet comes into direct contact with liquid nitrogen. This is distinct from the more generally observed Leidenfrost phenomenon that occurs when a liquid droplet is self-vaporized on a hot plate. In the case of rapid cooling, the phase transition from liquid to vitrified solid (i.e., vitrification) and the levitation of droplets on liquid nitrogen (i.e., Leidenfrost phenomenon) take place simultaneously. Here, we investigate these two simultaneous physical events by using a theoretical model containing three dimensionless parameters (i.e., Stefan, Biot, and Fourier numbers). We explain theoretically and observe experimentally a threshold droplet radius during the vitrification of a cryoprotectant droplet in the presence of the Leidenfrost effect.
authors.affiliation: Bio-Acoustic-Microelectromechanical Systems in Medicine Laboratory, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Center for Bioengineering, Boston, MA 02115, USA.
authors.forename: Young S
authors.initials: YS
authors.lastname: Song
authors.forename: Douglas
authors.initials: D
authors.lastname: Adler
authors.forename: Feng
authors.initials: F
authors.lastname: Xu
authors.forename: Emre
authors.initials: E
authors.lastname: Kayaalp
authors.forename: Aida
authors.initials: A
authors.lastname: Nureddin
authors.forename: Raymond M
authors.initials: RM
authors.lastname: Anchan
authors.forename: Richard L
authors.initials: RL
authors.lastname: Maas
authors.forename: Utkan
authors.initials: U
authors.lastname: Demirci
mesh_terms: D000465:Algorithms; D003198:Computer Simulation; D003451:Cryoprotective Agents / Q000737:chemistry*; D003460:Crystallization; D008956:Models, Chemical; D009584:Nitrogen / Q000737:chemistry*; D014835:Volatilization
chemical_list: D003451:Cryoprotective Agents; D009584:Nitrogen