Soft magnetic nanocomposite microgels by in-situ crosslinking of poly acrylic acid onto superparamagnetic magnetite nanoparticles and their applications for the removal of Pb(II) ion

Abstract

FeCl3·6H2O and FeCl2·4H2O is used to produce a water-based nanometer Fe3O4 magnetic fluid, which is in-situ modified in liquid paraffin with silane in the form of water-in-oil emulsion. The emulsion of the resulting multi-functionalized Fe3O4 magnetite nanoparticles is then used as the only crosslinker and in-situ grafted with acrylic acid to produce beaklike soft magnetic nanocomposites microgels. This “one-pot” process has a number of advantages over the traditional methods: it is a simpler process; it avoids aggregation of nanometer Fe3O4; and it shows a much improved mechanical strength credited to the covalent crosslinking between the rigid Fe3O4 skeleton and the soft PAA blocks. The obtained microgels have showed selective adsorption to Pb(II), and the adsorbed Pb(II) can be easily desorbed, suggesting good reusability. Also, the microgels exhibit certain magnetic properties, therefore providing a convenient approach for stirring or separation by applying external magnetic field.