DETECTION OF THE HETEROCOAGULATION-STABILITY TRANSITION IN BINARY COLLOIDAL SYSTEMS BY ELECTROPHORETIC LIGHT-SCATTERING SILICA-SILICA AMINOPROPYL SYSTEM/
J. Skvarla, DETECTION OF THE HETEROCOAGULATION-STABILITY TRANSITION IN BINARY COLLOIDAL SYSTEMS BY ELECTROPHORETIC LIGHT-SCATTERING SILICA-SILICA AMINOPROPYL SYSTEM/, Colloids and surfaces. A, Physicochemical and engineering aspects, 110(2), 1996, pp. 135-139
Electrophoretic light scattering is shown to detect the heterocoagulat
ion-stability transition, induced by a variation of pH, in a model bin
ary colloidal (silica-silica/aminopropyl) system. For stable mixtures
of silica, bimodal zeta-potential distributions have been obtained wit
h peak positions corresponding to those of monomodal zeta-potential di
stributions due to the separate silicas, while for heterocoagulated mi
xtures, only monomodal distributions appeared with peak positions betw
een those of separate silicas. The isoelectric point was found at pH 3
.7 and 6.25 for silica and silica/aminopropyl respectively, and the he
terocoagulation-stability transition was predicted at pH 6.6. This is
in accordance with the DLVO theory.