Styrylmethyl(trimethyl)ammonium methacrylate polyampholyte latexes

Monodisperse polyampholyte latexes that contain 25/23 and 29/18 mol % of po lystyrylmethyl(trimethyl)ammonium and methacrylate groups were prepared by emulsion polymerization of vinylbenzyl chloride (VBC), tert-butyl methacryl ate (tBMA), styrene, and divinylbenzene followed by stepwise conversion of the VBC and tBMA to cations and anions, respectively. As NaCl is added to a queous dispersions, the polyampholyte latexes shrink up to 0.5 M and then s well up to 5 M NaCl, in which the particles are colloidally stable. The pol yampholyte latexes also are colloidally stable in 1.2 M BaCl2 solution. In contrast, the precursor quaternary ammonium chloride polyelectrolyte latexe s coagulate rapidly in NaCl and BaCl2 solutions.