Patent ID: 8197890

Claim:
A method for producing magnetic nanostructures comprised of an assembly of magnetic nanorods held together by dipole interaction in a dendritic pattern, which method comprising: a) dissolving an effective amount of a surfactant into a non-polar organic solvent with sufficient mixing to cause the formation of a reverse micelle microemulsion; b) dividing said reverse micelle microemulsion into a first fraction and a second fraction; c) blending into said first fraction an aqueous solution having dissolved therein one or more metal salts wherein at least one of the metals has magnetic properties, thereby forming a metal salt microemulsion comprised of reverse micelles in a continuous non-polar organic phase, which reverse micelles are comprised of an aqueous core of metal salt solution encased in a surfactant shell; d) blending into said second fraction an effective amount of an aqueous precipitating agent solution, thereby resulting in the formation of a precipitating agent microemulsion comprised of reverse micelles in a continuous non-polar organic phase, which reverse micelles are comprised of an aqueous core of precipitating agent solution encased in a surfactant shell; e) simultaneously: (i) applying a magnetic field of effective strength; and (ii) blending at least a portion of the metal salt microemulsion with at least a portion of the precipitating agent microemulsion, thereby resulting in the simultaneous precipitation and formation of magnetic nanostructures comprised of an assembly of magnetic nanorods held together by dipole interaction in a dendritic pattern, which nanorods are comprised of a series of magnetic nanoparticles held together by dipole magnetic forces, in the aqueous core of said reverse micelles; f) extracting at least a portion of the magnetic nanostructures with an effective amount of a polar organic solvent wherein the magnetic nanostructures migrate to the polar organic solvent phase in the form of a colloidal dispersion polar organic solvent phase; g) separating the colloidal dispersion polar organic solvent phase from the non-polar solvent phase; h) heating said colloidal dispersion polar organic solvent phase of step g) above at an effective temperature for an effective amount of time to drive off at least a portion of any remaining water and surfactant, thereby resulting in substantially dried magnetic nanostructures comprised of assemblies of magnetic nanorods held together in a dendritic pattern by dipole interaction; and i) collecting the resulting dendritic magnetic nanostructure product.