Adsorption isotherms of polyampholytes at charged spherical particles

We develop a scaling theory of adsorption of polyampholyte chains at charged spherical particles from dilute low salt solutions. The adsorption is due to the polarization of polyampholyte chains in the electric field created by charged particles. The expressions for the surface coverage and the thickness of adsorbed layer are derived as functions of bulk polymer concentration, particle size, and surface charge density. We also describe the effect of the electric field of the particles on the dissociation equilibrium of adsorbed polyampholytes. The predictions of our scaling model are compared with the experiments on gelatin/latex systems.