Magnetic open porous microspheres via high internal phase emulsion templating as efficient Pb adsorption material

Emulsion templating enables the synthesis of hierarchically porous polymers. By adding another phase to this process and therefore, creating a multiple emulsion templating method, it is possible to synthesise hierarchically porous microspheres. In this study water-in-oil-in-water double emulsion templating was used to prepare porous microspheres by utilising thiol-ene click chemistry. For this trimethylolpropane tris(3-mercaptopropionate) and trimethylolpropane triacrylate were used. To the monomer phase magnetic nanoparticles were added to synthesise polyHIPE microspheres with magnetic properties. The higher magnetic nanoparticles (MNPs) content also affected the morphology and microsphere size. With increasing MNPs content the bead diameter decreased, while the diameter of the primary pores of the cross-section increased. However, while the MNPs influenced the morphology, the chemical composition was not influenced. The microspheres were used for the removal of Pb2+. From a 2.9 mg/L solution up to 97.0% of Pb was removed after 24 h.