Hysteretic Swelling/Deswelling of Polyelectrolyte Brushes and Bilayer Films in Response to Changes in pH and Salt Concentration.

Abstract We use a quartz crystal microbalance with dissipation (QCM-D) to investigate the swelling/de-swelling and hysteresis in brushes of weakly ionizable polyanion poly(acrylic acid) (PAA) brushes and bilayers containing a PAA brush and a poly(ethylene imine) (PEI) overlayer [...].