Formation, properties and fractal structure of particle gels

In this paper, the authors give a short introduction to fractal geometries as applied to particle aggregates. Among the various techniques that can be used to analyze these structures, the recently introduced confocal scanning laser microscopy (CSLM) appears to be rather powerful since it provides direct information, as opposed to the indirect information provided by other methods. Therefore, most emphasis is put on this technique, since its introduction in colloid science is new and to the authors' knowledge has not yet been described. The fractal dimensionalities obtained with the various techniques are compared and analyzed, and finally the disturbing effect of sedimentation is considered, in order to establish to what extent microgravity can possibly diminish this interfering effect in particle gel formation.