Preparation of Fe^sub 3^O^sub 4^ Spherical Nanoporous Particles Facilitated by Polyethylene Glycol 4000

Abstract

Much interest has been attracted to the magnetic materials with porous structure because of their unique properties and potential applications. In this report, Fe^sub 3^O^sub 4^ nanoporous particles assembled from small Fe^sub 3^O^sub 4^ nanoparticles have been prepared by thermal decomposition of iron acetylacetonate in the presence of polyethylene glycol 4000. The size of the spherical nanoporous particles is 100-200 nm. Surface area measurement shows that these Fe^sub 3^O^sub 4^ nanoporous particles have a high surface area of 87.5 m^sup 2^/g. Magnetization measurement and Mössbauer spectrum indicate that these particles are nearly superparamagnetic at room temperature. It is found that the morphology of the products is greatly influenced by polyethylene glycol concentration and the polymerization degree of polyethylene glycol. Polyethylene glycol molecules are believed to facilitate the formation of the spherical assembly.