Complexation of a polyelectrolyte with oppositely charged spherical macroions: Giant inversion of charge

Complexation of a long flexible polyelectrolyte (PE) molecule with oppositelycharged spherical particles such as colloids, micelles, or globular proteins ina salty water solution is studied. PE binds spheres winding around them, whilespheres repel each other and form almost periodic necklace. If the total chargeof PE is larger than the total charge of spheres, repulsive correlations of PEturns on a sphere lead to inversion of the net charge of each sphere. In theopposite case, we predict another correlation effect: under-screened by PEspheres bind to PE in such a great number that they invert charge of PE. Theinverted charge by absolute value can be larger than the bare charge of PE evenwhen screening by monovalent salt is weak. At larger concentrations ofmonovalent salt, the inverted charge can reach giant proportions. Our theory isin qualitative agreement with recent experiments on micelles-PE systems.Comment: Various additions and corrections to the text, Figures and references. Accepted for publication in J. Chem. Phys. 200