Modeling the fractal growth of templated, mesoporous silica films

Brewster angle micrographs have been obtained of the development of a silica film grown at an air-water interface with use of the surfactant template cetylpyridinium chloride. The micrograph images showed that the growing silica film exhibited complex, fractal-like patterns. These images have been analyzed to determine the values of the fractal dimension and lacunarity, and the forms of the autocorrelation function and Euclidean crossover behavior of the silica clusters have been observed. These statistical descriptors have been compared with the equivalent properties of simulated images of model structures generated by computer using a particular variant of the cluster-cluster aggregation (CCA) algorithm. Good agreement was found between the characteristic properties of typical experimental images and the simulated images. It was, therefore, suggested that the CCA process is a good model for the growth of the silica films.