A small-angle X-ray scattering study of aggregation and gelation of colloidal silica

摘要: Abstract Aggregation and gelation in colloidal silica dispersions have been studied by time-resolved, small-angle X-ray scattering. Two different ways of raising the ionic strength, leading to destabilization dispersions, examined. In situ urease-catalyzed hydrolysis urea has used as well an approach with simple mixing sols salt solutions. For concentrated structures result from two methods. Structures differ also gelled state, essentially no fractal scattering directly mixed samples whereas on intermediate length scales is observed for destabilized samples. contrast, more dilute particle concentrations, similar are generated both cases at close agreement. However, gel times drastically some methods, do conditions gelation. These differences tentatively rationalized degree irreversible aggregation occurring stage that, given sufficient time, leads