Magnetic resonance of magnetite nanoparticles dispersed in mesoporous copolymer matrix

Magnetic resonance is used to investigate fine particles of magnetite (Fe3O 4) synthesized as isolated nanoparticles (INP's) in a mesoporous styrene-di vinylbenzene (Sty-DVB) copolymer template, The magnetite nanoparticles were obtained through alkaline precipitation of ferrous sulfate, at different i ron (II) concentration (Q), in the sulfonated polymeric matrix. Analysis of the temperature (T) dependence of the resonance field (H-R) and resonance linewidth (DeltaH(R)) provide a useful way to estimate the average size of the magnetite nanoparticles. The resonance data indicates that the nanopart icle average diameter (D) increases as Q increases, in accordance with the data reported previously.