Macroions in salty water with multivalent ions: Giant inversion of charge

Screening of a strongly charged macroion by oppositely charged colloidal pa rticles, micelles, or short polyelectrolytes is considered. Because of stro ng lateral repulsion such multivalent counterions form a strongly correlate d liquid at the surface of the macroion. This liquid provides correlation-i nduced attraction of multivalent counterions to the macroion surface. As a result even a moderate concentration of multivalent counterions in the solu tion inverts the sign of the net macroion charge. We show that at high conc entration of monovalent salt the absolute value of inverted charge can be l arger than the bare one. This giant inversion of charge can be observed in electrophoresis.