Temperature of the solution of winter flounder antifreeze protein near ice surfaces in a narrow space

Experiments have been conducted into the unidirectional freezing of the aqueous solution of winter flounder antifreeze protein in a narrow gap between two cover glasses. A gap of 20 μm, which is narrower than the gaps used by Coger (32 μm) and Furukawa (60 μm), has been adopted. It is confirmed that the local temperature near the ice/solution interface can be measured accurately with a near-infrared spectroscopy. The temperature difference between the front and bottom edges of the serrated interface is found to be proportional to the distance between the front and bottom edges. Generally, as ice grows, the wide, shallow regions of the serrated interface become even wider, while the narrow, deep regions of the serrated interface become even deeper. These changes coexist. It is also observed in the case of the lowest interface velocity that the shallow, narrow region becomes shallower quickly, which does not satisfy the proportional relationship.