title: Attractive electrostatic forces between identical colloidal particles induced by adsorbed polyelectrolytes.
abstract: Polyelectrolytes adsorb strongly at oppositely charged surfaces, thereby dramatically influencing the corresponding interaction forces. In this letter, we report on direct force measurements with the atomic force microscope (AFM) between two individual particles in an aqueous colloidal suspension in the presence of polyelectrolytes near the isoelectric point. From systematic variations of the molecular mass, the ionic strength, and analysis of adhesion events, we conclude that the observed attractive forces are mainly due to electrostatic patch-charge interactions. The same type of attractive forces is equally influencing interactions between proteins as well as hydrophobic or mineral surfaces.
authors.forename: Ionel
authors.initials: I
authors.lastname: Popa
authors.forename: Graeme
authors.initials: G
authors.lastname: Gillies
authors.forename: Georg
authors.initials: G
authors.lastname: Papastavrou
authors.forename: Michal
authors.initials: M
authors.lastname: Borkovec
mesh_terms: D000327:Adsorption; D003102:Colloids / Q000737:chemistry; D004573:Electrolytes / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D011108:Polymers / Q000737:chemistry*; D011137:Polystyrenes / Q000737:chemistry; D055672:Static Electricity; D013499:Surface Properties; D014867:Water / Q000737:chemistry
chemical_list: D003102:Colloids; D004573:Electrolytes; D011108:Polymers; D011137:Polystyrenes; D014867:Water; C003321:polystyrene sulfonic acid