Organic/inorganic hybrid nanospheres based on hyperbranched poly(ethylene imine) encapsulated into silica for the sorption of toxic metal ions and polycyclic aromatic hydrocarbons from water

Organic-inorganic hybrid silica nanospheres were prepared through a biomimetic silicification process in water at ambient conditions by the interaction of low cost poly(ethylene imine) hyperbranched polymer with silicic acid. The characterization of these nanoparticles by FTIR spectroscopy, scanning electron microscopy (SEM), zeta-potential and dynamic light scattering (DLS) experiments confirmed that the dendritic polymer was incorporated into the silica network. Preliminary experiments show that these hybrid nanoparticles can be employed for the removal of toxic water contaminants. Hybrid nanospheres' sorption of two completely different categories of pollutants, i.e. metal ions such as Pb(2+), Cd(2+) Hg(2+). Cr(2)O(7)(2-), and polycyclic aromatic hydrocarbons such as pyrene and phenanthrene, was largely enhanced in comparison with the corresponding polymer-free silica nanospheres. This was attributed to the to the formation of conventional metal-ligand and charge-transfer complexes proving that although integrated into the silica network poly(ethylene imine) retains its chemical properties. (C) 2009 Elsevier B.V. All rights reserved.