Instabilities in dispersions of “hairy” particles on adding solvent-miscible polymers

✍ Scribed by Nick Cawdery; Andrew Milling; Brian Vincent

• Book ID: 103966948
• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 798 KB
• Volume: 86
• Category: Article
• ISSN: 0927-7757
• DOI: 10.1016/0927-7757(94)02751-x

✦ Synopsis

This paper outlines some recent experrmental observations regarding depletion flocculation in dispersions of particles carrying terminally anchored polymer chains. Two types of model experimental system are used: (1) dispersions in various non-aqueous media (primarily dioxan) of silica particles carrying terminally grafted poly(methy1 methacrylate) chains; (2) aqueous dispersions of polystyrene latex particles carrying terminally grafted poly(ethylene oxide) chains. A number of specific effects are investigated:

(I) the role of surface coverage of the grafted chains in controlling the efficacy of the depletion interaction:

(2) the possible role of electrostatic forces emanating from surface charge groups on the particles, particularly with regard to non-aqueous systems and how these may offset the depletion interaction; (3) for aqueous systems, the role of polyelectrolytes in depletion flocculation.