Functionalization and applications of nanosized gamma-Fe2O3 particles

A novel method to prepare nanosized gamma-Fe2O3 particles containing reactive thio and/or disulphide groups using molecular self-assembly method is described. The monolayers are formed from self-assembled bolaamphiphiles, e.g., 16-mercaptohexadecanoic acid (HS-C15H30-COOH), and characterized using x-ray photoelectron spectroscopy. The magnetization of surfactant-coated particles is determined using a vibrating sample magnetometer. The potential uses of functionalized magnetic particles in recovering precious (Ag+) and base (CU2+) metal ions from industrial effluent are examined. The modification of thiol on coated-magnetic particles by controlled oxidation is also described to extend the application of self-assembled organic monolayers to stabilizing ferrofluids. (C) 1996 American Institute of Physics.