Analysis of ice crystal growth for a crystal surface containing adsorbed antifreeze proteins

The adsorption of antifreeze protein (AFP) molecules to the ice crystal sur face during melt growth from an AFP solution results in disturbance of the growth kinetics at the surface interface. In this paper, the growth pattern related to the potential for crystal growth as well as the crystal surface topography have been studied. The crystal shape and size were found to be strongly dependent on the supercooling in the crystal's surrounding liquid. In between a transition temperature and the freezing temperature, needle-t ype crystals were formed, growing rapidly in the c-axis direction. The surf ace was investigated using a scanning tunneling microscope (STM) and a syst ematic groove/ridge pattern aligned 65 degrees ( +/- 5 degrees) to the hexa gonal side on one bipyramidal plane observed with length and width similar to the size of the AFP molecule. The depth of the grooves, ranging from 2 t o 10 nm indicates the curvature of ice. (C) 1999 Elsevier Science B.V. All rights reserved.