COMPLEXATION BEHAVIOR OF POLYAMPHOLYTES AND CHARGED OBJECTS

We study theoretically the interaction of a polyampholyte chain with c harged planes, cylinders, and spheres. Due to the random character of the charge distribution along the chain, a polyampholyte possesses a s pontaneous dipole moment, which can interact favorably with charged ob jects. Depending on the charge strength of the object and the polyamph olyte length and fraction of charged monomers, this attractive interac tion can be strong enough to induce adsorption. The addition of salt w eakens the trend to adsorption, but proves necessary to adsorb polyamp holytes of the same net charge as the charged object in the case of pl anes and cylinders. Long polyampholytes form globules, for which the n umber of uncompensated charges and thus the spontaneous dipole moment is reduced. Nevertheless, globules can adsorb on charged objects via t wo pathways: they either adsorb as a whole, (intact globule), or they are dissolved into a coil state prior to adsorption. Applications to t he complexation behavior of polyampholytes with stiff, rodlike polyele ctrolytes and with charged microspheres or charged spherical micelles are given.