Magnetoliposomes based on NixCu1-xFe2O4 or NiFe2-yAlyO4 nanocrystals for applications in magnetic separation and classification

Abstract

Ferrites are a broad class of compounds with general formula MFe2O4, where M stands for a divalent metallic cation. Among these, copper ferrite (CuFe2O4) presents a moderate saturation magnetization, while nickel ferrite (NiFe2O4) holds a large one. Mixed ferrites with composition NixCu1-xFe2O4 were then prepared by coprecipitation method, in order to control the saturation magnetization with the fraction of Ni. Another possibility is the partial substitution of iron atoms with aluminium, as NiAl2O4 nanocrystals show very low saturation magnetization. Thus, ferrites of NiFe2-yAlyO4 composition were also obtained. XRD spectra of the obtained nanoparticles show the spinel-type crystalline phase. Solid magnetoliposomes of the prepared mixed ferrites were obtained, and their bilayer structure was proven by the use lipophilic fluorescence probes.