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

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 (10 $(1) over bar $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, delta T, at the interfaces of prismatic faces as a function of growth rate. delta 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 delta T was qualitatively explained by the interaction between the rejection and incorporation rates of AFGP molecules at the growing interface. (c) 2004 Elsevier B.V. All rights reserved.