Nucleation and growth of three-dimensional aggregates in supersaturated monolayers at the air-water interface: constant surface pressure relaxation of methyl stearate

Nucleation and growth of three-dimensional (3D) structures in supersaturate d methyl stearate monolayers were studied. The constant surface pressure re laxations were analysed quantitatively by comparison of two models which we re developed for (i) the limiting cases of nucleation and growth with assum ed geometric shape of the 3D centres, and (ii) nucleation according to the exponential law with formation of lenticular centres. Both nucleation-growt h models provide an excellent fit to the experimental data. The relaxation data correspond to the limiting case of progressive nucleation. The compari son corroborates the compatibility of the two models, but the generalised m odel for nucleation according to the exponential law and the formation of l enticular centres has the advantage of being able to calculate the nucleati on rate constants. Detailed information on the texture and growth kinetics of the microscopic 3D aggregates, which correspond to the overlapping struc tures of the theoretical models, are obtained using Brewster angle microsco py. (C) 1998 Elsevier Science B.V. All rights reserved.