Fig. 1

(a) Hydrophilic magnetite nanoparticles prepared by the co-precipitation method, (b) OCMNs as prepared, (c) OCMNs show a magnetic response to an external magnet, (d,e) The OCMNs are well-dispersed in the oil phases (styrene and glycerin, respectively), (f) OCMNs are poorly dispersed in the aqueous medium.