Deep Undercooling of Aqueous Droplets on a Superhydrophobic Surface: The Specific Role of Cation Hydration

J Phys Chem Lett. 2020 Apr 16;11(8):3058-3062. doi: 10.1021/acs.jpclett.0c00609. Epub 2020 Apr 6.

Abstract

An extraordinary prolonged freezing delay was detected for the first time for deeply undercooled sessile droplets of aqueous solutions of alkali metal chlorides deposited onto a superhydrophobic surface. Accounting for the variation in the hydration energy of ions, their distribution in the vicinity of charged interfaces of solution/air and solution/superhydrophobic surface allows qualitative description of the observed ice nucleation kinetics and ionic specificity in freezing phenomena.