PREPARATION AND CHARACTERIZATION OF POROUS CARBON LOADED WITH IRON PARTICLES - A POSSIBLE MAGNETIC CARRIER OF MEDICAL DRUGS

In order to design magnetic carriers for medical drugs, carbon-support ed iron samples with an iron content of 23, 29 and 43 wt.% have been p repared by impregnation of synthetic carbon with aqueous solution of i ron oxalate followed by calcination and by reduction in hydrogen. The samples obtained after reduction times of 15, 30, 45 and 60 min have b een characterized by Mossbauer spectroscopy, X-ray diffraction (XRD), and magnetization as well as adsorption measurements. Analysis of the Mossbauer and XRD data shows the presence of both oxidic and metallic iron particles with sizes in the 3-30 nm range. The saturation magneti zation of the carbon loaded with 23, 29, and 43 wt.% iron has been det ermined to be 20, 30 and 80 emu per gram of solid, respectively. The h ydrogen treatment induces in addition an increase of the meso- and mac ropore volumes of the iron-loaded carbon by a factor of about 1.4 with respect to the unloaded carbon. This fact is shown to lead to a bette r adsorption capacity for macromolecular drugs like streptomycin and v itamin B12. (C) 1997 Elsevier Science B.V.