Properties of mesostructured silica coated CoFe2O4 versus 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.