Synthesis of polypyrrole–polystyrene composite microspheres via pseudo-multicomponent heterophase polymerization and the potential application on Cr(vi) removal

Abstract

Polypyrrole–polystyrene (PPy–PS) composite hollow microspheres with a dry-plum-like morphology were prepared via pseudo-multicomponent heterophase polymerization in an aqueous dispersion system. The monomers of pyrrole (Py) and styrene (St) were simultaneously added into the reactor with the existence of azodiisobutyronitrile. The oxidization polymerization of Py was first initiated by the addition of ammonium persulfate, and the radical polymerization of St was subsequently initiated by the elevated temperature. Finally, composite micron-sized spheres were obtained with hierarchical structures. The microspheres are hollow inside, with PPy nano-particles bound by a PS matrix for the building of the wall-shell. The decoration of tiny PPy particles at the surface leads the microspheres to be an effective adsorbent to isolate Cr(VI) ions from water. The adsorption kinetics and isotherm result of the microspheres agree well with the pseudo-second-order rate model and Langmuir isotherm mode, respectively.