Properties of mesostructured silica coated CoFe2O4versus Fe3O4-silica composites

Ferrite-based composite materials have many applications in biomedicine, catalysis, magnetic separations etc. Cobalt ferrite and magnetite were synthesized by co-precipitation method using oleic acid as capping agent. The crystalline CoFe2O4 nanoparticles with an average size of 12 nm were obtained at 90 °C. The magnetic composite materials were prepared by coating the magnetic nanoparticles with MCM-41 mesoporous silica. Fe3O4 nanoparticles and magnetite-based composites presented superparamagnetic behavior, while CoFe2O4 and silica coated cobalt ferrite material exhibited ferrimagnetic properties. The obtained composites had high specific surface area values in the range of 612-784 m2/g and no significant in vitro toxicity on adherent epithelial opossum kidney cells that recommend them as platform for drug delivery systems.