Method for making nanomaterials
View Patent ↗A method of making a nanostructure by preparing a face centered cubic-ordered metal nanoparticle film from metal nanoparticles, such as gold and silver nanoparticles, exerting a hydrostatic pressure upon the film at pressures of several gigapascals, followed by applying a non-hydrostatic stress perpendicularly at a pressure greater than approximately 10 GPA to form an array of nanowires with individual nanowires having a relatively uniform length, average diameter and density.
1. A method of making a nanostructure, comprising:
preparing a face centered cubic-ordered metal nanoparticle film, wherein said metal is selected from the group consisting of gold and silver,
exerting a hydrostatic pressure upon said film up to a pressure of approximately 8.9 GPa, and
subsequently applying a non-hydrostatic stress perpendicularly to form an array of nanowires.
2. The method of claim 1 wherein said array of nanowires is dispersed in an organic solvent to form individual nanowires.
3. The method of claim 1 wherein said preparing a face centered cubic-ordered metal nanoparticle film occurs by mixing metal nanoparticles and a matrix material selected from the group consisting of polystyrene and poly(methyl methacrylate) in a polar solvent and subsequently evaporating said polar organic solvent by a process selected from the group consisting of spin-coating and casting.
4. The method of claim 1 wherein said non-hydrostatic stress is a pressure of up to 13 GPa.
5. The method of claim 4 wherein said pressure is subsequently decreased to ambient pressure at ambient temperature.
6. The method of claim 2 wherein said nanowires are formed without interspersed organic materials.
7. The method of claim 1 wherein said array of nanowires has a density of approximately 1.7×10 12 nanowires per square centimeter.
8. The method of claim 2 wherein said nanowires have an average diameter of approximately 6 nm.
9. The method of claim 2 wherein said nanowires have a length ranging from 400 nm to 1.5 μm.
10. The method of claim 2 wherein said organic solvent is toluene.
11. The method of claim 1 wherein a diamond anvil cell is used to exert said hydrostatic pressure.
12. The method of claim 1 wherein the hydrostatic pressure is exerted upon said film at ambient temperature.
13. The method of claim 3 wherein said metal nanoparticles have an average diameter of approximately 5 nm.