MOLECULAR DETAILS OF THE SOLVENT INDUCED FLOCCULATION OF DILUTE STERICALLY STABILIZED POLYMER COLLOIDS

The incipient flocculation behavior of sterically stabilized nonaqueous dispersions has been extensively investigated. These studies have identified the flocculation conditions either visually or using turbidity measurements. Such techniques identify the gross flocculation behavior of the colloid but do not furnish any information about the flocculation process at the molecular level. In this paper, the authors outline fluorescence energy transfer experiments which allow the opportunity to follow the change in conformation of the steric barrier as the solvency of the dispersion medium is varied. It is concluded from such experiments that in dilute sterically stabilised dispersions, the steric barrier collapses in the vicinity of the flocculation point.