1.1 Synergistic or Antagonistic Effects of Polymer/Surfactant Supramolecular Assembly on the Colloidal Depletion Force
(Room 243-245)
09 Apr 18
2:00 PM
-
2:30 PM
Tracks:
Session 1: Powder Coatings, Session 1: Science Today - Coatings Tomorrow
When microscopic "colloidal" particles are suspended in a solution containing polymers, the polymers tend to be excluded from the gaps between particles. This exclusion gives rise to a force called the depletion force, which can draw particles together to form aggregates. Some industrial processes take advantage of the depletion force by promoting aggregation of contaminant particles to remove them from solution. However, the depletion force may be undesirable in other processes where ingredients must remain in solution, such as paint pigment particles or active agents in pharmaceuticals. Such liquid products must be formulated to prevent depletion-induced aggregation. When ionic surfactants are also present in the polymer solution, they can bind to the polymers and alter the depletion force in ways that are not completely understood. This research will examine various kinds of polymer/surfactant mixtures to better understand how polymer-surfactant binding influences the depletion force and the stability of the suspension. A colloidal probe atomic force microscope is used to measure the depletion force in the polymer/surfactant mixtures. The results of the work will be useful to engineers who manufacture and process colloidal fluids, including paints, coatings, topical medications, and personal care products.