THEORETICAL-ANALYSIS OF THE CROSS-LINKING EFFECT ON THE POLYELECTROLYTE-SURFACTANT INTERACTION

The cooperative binding of a linear as well as a cross-linked polyelectrolyte with an oppositely charged surfactant has been theoretically analyzed. The hydrophobic interaction has been treated using the nearest-neighbor interaction model, while the electrostatic interaction has been calculated using the rodlike model. The general formulas derived on the basis of the free energy minimum principle predicted that the crosslinkage enhances the initiation process but strongly suppresses the cooperativity due to the osmotic pressure in the network domain. The theoretical results showed fairly good agreement with the experimental data, confirming the essential features of the theory.