Disassembly of Polyelectrolyte/Surfactants Complex Induced by Macroions

The effects of charge number, diameter, surface charge density as well as concentration of macroions on the structure of a polyelectrolyte/surfactants complex were investigated using coarse- grained molecular dynamics simulation. We found that the macroions that had the same charge as the polyelectrolyte had no obvious effect on the structure of the polyelectrolyte/surfactants complex. However, the macroions with opposite charge to the polyelectrolyte can induce the release of surfactant from the polyelectrolyte and even lead to the complete disassembly of the polyelectrolyte/surfactants complex and the formation of a macroion/polyelectrolyte complex. The induction effect increases with an increase in charge number. For microions with the same charge number, smaller microions were found to cause desorption of the surfactant more easily. However the opposite effect was found for the diameter at a fixed charge density. The concentration of macroions also affects the structure of the complex greatly and the surfactants that are released from the polyelectrolyte increase with the macroion concentration and finally a macroion/polyelectrolyte complex with reversed charges is formed.