Patent ID: 7588624
Filing Date: 2009-09-15
Classification: B22F,B82Y,C30B

Abstract:
1. A method of producing gold nanoprisms comprising the steps of a) admixing a suspension of gold seed nanoparticles and a first growth solution to form a first mixture, wherein the volume ratio of first growth solution to suspension is at least 2:1, wherein the gold seed nanoparticles have a diameter of about 3 to about 10 nm, and wherein the first growth solution comprises a gold salt, a base, a reducing agent, and a surfactant, wherein the surfactant has a concentration in the first growth solution of at least 50% saturation at about 25° C.; b) admixing the first mixture and a second growth solution to form a second mixture, wherein the volume ratio of second growth solution to first mixture is at least 2:1, wherein the second growth solution comprises a gold salt, a base, a reducing agent, and a surfactant, wherein the surfactant has a concentration in the second growth solution of at least 80% saturation at about 25° C.; and c) admixing the second mixture and a third growth solution to form a third mixture, wherein the volume ratio of third growth solution to second mixture is at least 2:1, and wherein the third growth solution comprises a gold salt, a base, a reducing agent, and a surfactant, and wherein the surfactant has a concentration in the third growth solution of at least 80% saturation at about 25° C.; wherein the surfactants of the first, second, and third growth solutions are ammonium salts having at least one and up to four substituents having at least four carbons; and wherein the gold nanoprisms are triangular or a combination of triangular and spherical and are essentially free of rods, cubes, and branched structures, and the triangular nanoprisms have at least one edge length of about 100 to about 400 nm.