Adsorption and release of surfactant into and from multifunctional zwitterionic poly(NIPAm-co-DMAPMA-co-AAc) microgel particles.

We synthesize monodispersed zwitterionic microgel (ZI-MG) particles that undergo an extensive, reversible change in volume in response to environmental stimuli such as pH and temperature. These aqueous ZI-MG dispersions exhibit a minimum hydrodynamic diameter value at an adjustable isoelectric point (IEP). In addition, the study elucidates the controlled uptake and release of ionic and nonionic surfactants from these particle systems. The extent of surfactant loading and the ensuing relative swelling/deswelling behaviors within the colloidal polymer networks are explained in terms of their binding interactions.