Growth patterns and interfacial kinetic supercooling at ice/water interfaces at which anti-freeze glycoprotein molecules are adsorbed

Abstract

Ice crystal growth in a supercooled solution containing proteins such as anti-freeze glycoproteins (AFGPs) is inhibited by its adsorption at the ice/water interface. Although these proteins have dramatic consequences for natural biological processes and technological applications, little is known about the dynamic mechanism of ice growth inhibition. One-directional growth experiments were carried out to observe the pattern formation at the ice/water interface growing from an aqueous AFGP solution. Typical zigzag patterns composed of flat prismatic { 1 0 1 ¯ 0 } interfaces were observed in the final quasi-stable growth state. By analyzing the zigzag patterns, we were able to directly determine the interfacial kinetic supercooling, δ T , at the interfaces of prismatic faces as a function of growth rate. δ T linearly increased with increasing growth rate in the range below a critical growth rate, but its dependence showed the reversed relationship above the critical growth rate. This growth rate dependency of δ T was qualitatively explained by the interaction between the rejection and incorporation rates of AFGP molecules at the growing interface.