Efficiency of methanol induced flocculation of AgI hydrosol stabilized by polyacrylamide

Abstract

AgI hydrosol stabilized by polyacrylamide (PAAm) adsorbed from the dispersion medium was used in the studies. The efficiency of methanol induced flocculation of the system was examined at different polymer and electrolyte concentrations. Properties of PAAm in water–methanol–electrolyte mixtures were also examined using nephelometric and viscometric methods. Moreover, the solvent power of the medium for PAAm was concluded from experiments on the swelling of PAAm gel in media of different composition. Properties of AgI particles in the absence and in the presence of PAAm were deduced from their electrophoretic mobilities. The results obtained demonstrated the complex behavior of dispersions stabilized by polymer adsorbed from the solution. The important effect of free polymer concentration in the continuous phase on the dispersion properties was underlined. In particular, its effect on the reduction of efficiency of non-solvent induced flocculation is discussed.