Magnetically modified Al2O3 pillared clays

Surface modification of alumina pillared montmorillonite with magnetic iron oxide nanoparticles has been achieved by using as precursor a colloidal solution of magnetite in poly(vinyl alchohol). Two synthetic routes were developed differing in the number of steps. The magnetic and adsorption properties of the modified products were studied using Mossbauer spectroscopy, magnetization, and surface area measurements. All measurements showed that their magnetic and adsorption properties depend on the way of preparation. The Mossbauer spectra exhibited different superparamagnetic behavior for each modified product, whereas sorption analysis gave different surface areas and structural characteristics. TEM reveals the nano size of the iron oxides and furthermore their random dispersion at the external surfaces of the clay.