Redispersing and stabilizing agglomerates in an annular-gap high shear disperser

Unwanted agglomeration of submicron and nanoscale particles is an important problem. For many applications in particle technology, the desired form of particle products (produced from wet grinding or precipitation processes) is a stable primary particle suspension. Prior to use, a redispersion of agglomerated or aggregated (connected by solid bridges) particles is often necessary.Spontaneous agglomeration and reagglomeration processes happen for not sufficiently stabilized nano- and submicron scale particles. A successful redispersion into primary particles requires that the primary particle surfaces be stabilized simultaneously against reagglomeration by surfactants or surface charges.The redispersion of micron-sized agglomerates in a turbulent shear field of an annular-gap disperser is described in this investigation. The redispersion kinetic and the maximum agglomerate size were measured and used to find a function for the agglomerate strength in shear fields.

Employment of a sterical stabilization agent allowed agglomerate redispersion without the use of grinding media in an annular-gap high shear disperser.Figure optionsDownload as PowerPoint slideHighlights
► Redispersion submicron agglomerates
► Sterical stabilization
► High shear redispersion