Patent ID: 7514476
Filing Date: 2009-04-07
Classification: B01J,B82Y

Abstract:
1. A method for making a stable, concentrated metal nanoparticle colloid, comprising: (i) mixing together a solvent, a plurality of metal atoms, and a plurality of organic agent molecules, each organic agent molecule comprising at least one functional group capable of bonding with the metal atoms; (ii) reacting the metal atoms with the organic agent molecules to form a mixture comprising a plurality of complexed metal atoms and having a pH greater than about 4.25 and less than 7.0; and (iii) exposing the mixture to a reducing agent for a period of time of at least 0.5 hour in order to reduce the complexed metal atoms and form stable colloidal metal nanoparticles in the mixture, wherein the concentration of metal in the concentrated metal nanoparticle colloid is greater than about 150 ppm by weight.