Adsorption of Surfactant Dispersed Nanometer Magnetite

Abstract

Processing of fine particles in a slurry is a difficult problem. Methods to make fine particles magnetic have been developed recently and may offer a solution to this problem. Particles of nonmagnetic materials can be selectively rendered magnetic through surface interactions with magnetic reagents, which are prepared by dispersing nanoscale magnetite (about 10 nm diameter) with surfactants. When adsorption occurs, the magnetic susceptibility of the material is increased. Magnetic enhancement at several orders of magnitude can be achieved. Selectivity of the adsorption can be controlled by the functional groups of magnetic reagents and various surface interaction mechanisms. This approach allows a new degree of freedom for the processing of fine particles, even with conventional magnetic means. Separation and filtration are examples of the applications.