Heterogeneous Ice Nucleation on Polar Crystals: the Role of Water Clusters and Surface Charge

The ability to control the freezing temperature of super-cooled water (SCW) with auxiliaries is of vital importance in the living and unanimated worlds and currently identified as one of the top open questions in the ice sciences.

In the 90’s Prof. Meir Lahav, who is a member of our group, together with Prof. Leslie Leiserowitz were investigate super-cooled water freezing on organic monolayers and crystals. One of their finding was that alpha-amino acid crystals that have a polar axis induce a freezing point higher by 4° to 5°C than the corresponding crystals that do not have a polar axis ¹. In 2010 we published that that in pyroelectric LiTaO₃ crystal SCW freezes on a positively charged surface at a much higher temperature than on a negatively charged one ². In a recent publication, we show that the source of pyroelectric enhance SCW freezing is the surface charge and not the electric field ³. New results suggest that this charge effect occurs only on hydrophilic surfaces. In the case of hydrophobic surface, the initial water organization due to the crystal polarity is probably the dominate factor.

Reference:

¹ J. Majewski, R. PopovitzBiro, R. Edgar, M. ArbelHaddad, K. Kjaer, W. Bouwman, J. AlsNielsen, M. Lahav, and L. Leiserowitz, J Phys Chem B 101, 8874 (1997).

² D. Ehre, E. Lavert, M. Lahav, and I. Lubomirsky, Science 327, 672 (2010).

³ A. Belitzky, E. Mishuk, D. Ehre, M. Lahav, and I. Lubomirsky, J. Phys. Chem. Lett. 7, 43 (2016).