Diffusion limited growth of crystalline domains in phospholipid monolayers

The growth kinetics of two-dimensional crystalline phospholipid domains at the air/water interface is studied following a stepwise increase in density of interfacial molecules. In addition to pressure relaxation the development of domain size and shape and impurity distribution could be followed by fluorescence microscopy. All experimental findings agree, within a factor of 3, with results of simple model calculations. These consider the growth kinetics to be controlled by two-dimensional diffusion of impurities from the solid/lipid boundary (constitutional supercooling) and do not use any freely adjustable, but independently measurable parameters.