Polyelectrolyte bridging interactions between charged macromolecules

Polyelectrolyte chains confined by oppositely charged macroions can significantly modify the interactions between them. This polyelectrolyte mediated interaction depends on various parameters characterizing the polyelectrolyte as well as the surface of the macroion and can be either repulsive or attractive. Though polymers are mostly used to stabilize various colloidal systems they can just as well induce flocculation either by depletion interaction or by bridging. In the case of charged polymers we refer to this additional attractive interaction as polyelectrolyte bridging. This review will focus on equilibrium properties of polyelectrolyte mediated attraction between macroions, its theoretical underpinnings and its phenomenology.