Self-assembly of metallic nanoparticles into macroscopic, high-density, monolayer films

Patent metadata

Field	Value
Publication number	US-9321920-B2
Application number	US-201313771551-A
Country	US
Kind code	B2
Filing date	Feb 20, 2013
Priority date	Feb 21, 2012
Publication date	Apr 26, 2016
Grant date	Apr 26, 2016

Abstract

A method of forming a monolayer film of nanoparticles includes forming a fluid mixture by combining nanoparticles dispersed in water with a water-miscible organic solvent and a molecular ligand comprising a head group with affinity for the nanoparticle, and introducing the fluid mixture to a substrate in the presence of an air/fluid interface, thereby causing a monolayer film of nanoparticles to form on the substrate. Such monolayers films can include metallic nanoparticles such as gold, and possess substantially uniform spacing over at least a one centimeter length scale.

First claim

What is claimed is:

1. A method of forming a monolayer film of nanoparticles, the method comprising:
forming a fluid mixture by combining a plurality of nanoparticles dispersed in water, a water-miscible organic solvent, and a plurality of molecular ligands comprising head groups having affinity for the nanoparticles; and
introducing the fluid mixture to a substrate in the presence of an air/fluid interface, thereby causing a monolayer film of nanoparticles to form on the substrate,
wherein the steps of forming the fluid mixture and introducing said fluid mixture to a substrate in the presence of the air/fluid interface are sufficient to cause formation of the monolayer film of nanoparticles.

2. The method of claim 1 , wherein said nanoparticles are metallic.

3. The method of claim 2 , wherein said nanoparticles are gold.

4. The method of claim 1 , wherein said nanoparticles comprise a polymer, semiconductor, biomolecules, inorganic and/or organic materials, or combination thereof.

5. The method of claim 1 , wherein said nanoparticles have spherical or rod-shaped geometry.

6. The method of claim 1 , wherein
said head group of said molecular ligand comprises thiol, isocyanide, or phosphine; and
said molecular ligand further comprises a tail group of terminal alkene or alkyne, carboxylic acid, thiol, or amine.

7. The method of claim 1 , wherein the water-miscible organic solvent is selected from the group consisting of tetrahydrofuran (THF), 2-methyltetrahydrofuran, acetone, methanol, DMSO, and acetonitrile.

8. The method of claim 1 , wherein the nanoparticles are functionalized with ligands for click chemistry.

9. The method of claim 1 , further comprising crosslinking the monolayer film.

10. The method of claim 1 , further comprising depositing one or more additional monolayer films atop said monolayer film.

11. The method of claim 1 , wherein said substrate is ridged, flexible, rigid, flat, curved, patterned, and/or composite and is optionally modified with one or more surface chemistries.

12. The method of claim 1 , wherein the combining occurs in a vessel, and:
(1) said substrate is an interior wall of the vessel, or
(2) said substrate is apart from the vessel.

13. The method of claim 1 , further comprising separating said substrate from said monolayer film and obtaining a free-standing monolayer film.

14. The method of claim 1 , wherein said fluid mixture further comprises surfactants and/or ligands operable to modify surface tension at said air/fluid interface, thereby controlling orientational and/or positional order of said nanoparticles.

15. A method of forming a monolayer film of nanoparticles, the method comprising:
forming a fluid mixture by combining a plurality of nanoparticles dispersed in water, a water-miscible organic solvent, and a plurality of molecular ligands comprising head groups having affinity for the nanoparticles; and
introducing the fluid mixture to a substrate in the presence of an air/fluid interface, thereby causing a monolayer film of nanoparticles to form on the substrate, while applying pressure, electromagnetic radiation, and or an electric and/or magnetic field effective to control positional order and/or orientation of said nanoparticles during formation of said monolayer film.

16. A method of forming a monolayer film of metallic nanoparticles, the method comprising:
combining metallic nanoparticles in water with an ionic surfactant, tetrahydrofuran (THF), and thiol-ligands to form a fluid mixture, and
introducing the fluid mixture to a substrate in the presence of an air/fluid interface in a manner effective to evaporate the THF more quickly than the water, thereby allowing a monolayer film of metallic nanoparticles to form on the substrate.

17. The method of claim 16 , wherein said metallic nanoparticles are gold.

Assignees

• Fontana Jake
• Naciri Jawad
• Ratna Banahalli R
• Us Navy

Inventors

• Fontana Jake
• Naciri Jawad
• Ratna Banahalli R

Classifications

• B22F1/054

  Nanosized particles · CPC title

• B22F1/0547

  Nanofibres or nanotubes · CPC title

• B22F1/102

  Metallic powder coated with organic material · CPC title

• B22F2007/042

  characterised by the layer forming method · CPC title

• B82Y30/00

  Nanotechnology for materials or surface science, e.g. nanocomposites · CPC title