Methods and apparatus for depositing nanoparticles on a substrate

• US 20080187657A1
• Filed: 09/18/2007
• Published: 08/07/2008
• Est. Priority Date: 09/19/2006
• Status: Active Grant

• Current Assignee: The Board of Regents of the University of Colorado (University of Colorado System)
• Original Assignee: The Board of Regents of the University of Colorado (University of Colorado System)
• Inventors: Altan, M. Cengiz, Aktas, Levent
• Granted Patent: US 8,020,508 B2
• Time in Patent Office: Days
• US Class Current: 427/180
• CPC Class Codes: B05D 1/12 Applying particulate materials B05D1/06, B05D1/10 take precedence
• CPC Class Codes: B05D 2201/04 Laminate
• CPC Class Codes: B05D 2401/32 applied as powders
• CPC Class Codes: B05D 3/0493 using vacuum
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: Y10S 977/773 Nanoparticle, i.e. structure having three dimensions of 100 nm or less
• CPC Class Codes: Y10S 977/841 Environmental containment or disposal of nanostructure material
• CPC Class Codes: Y10S 977/858 including positioning/mounting nanostructure

Abstract

The present invention is a process for uniformly depositing nanomaterials having particles smaller than 1 μm (i.e., nanoparticles) onto a surface of a base material (substrate or surface). The process is used to deposit any solid (nanoparticle) of any shape such as nanofibers, nanotubes, nanoclays (e.g., platelet shaped), nano-spheres, or irregularly shaped granules. The base material upon which the nano-particles are deposited can be made of any material. The method substantially prevents the deposition on the base material of larger particles (contaminants or clusters of the nanoparticles) which are often mixed with the nanomaterials. The amount of deposition and the range of particle sizes to be deposited can also be controlled by this method. Maintaining deposition uniformity, controlling the amount of deposition, and the elimination of larger particles enhances the utility of nanomaterials, and by subsequent processing, enables the development of multifunctional composite materials (or other coated substrates) to be used in commercial applications. In the present invention nanoparticles are applied to other base materials by substantially eliminating deposition of larger clusters or aggregates of nano-sized materials or other large impurities of other materials upon or in the base materials by positioning the base material within an upper portion of a deposition chamber.

Claims

1. A method for depositing nanoparticles upon a deposition substrate, comprising:

providing a container assembly comprising;

a deposition chamber having an outer wall, an inner wall, an inner space, and upper end and a lower end, and the inner space having an upper level and a lower level positioned below the upper level;

a nanomaterial feeding container for containing a nanomaterial; and

a nanomaterial mixing and ejection device for mixing the nanomaterial from the nanomaterial feeding container and ejecting the mixed nanomaterial through an ejection orifice into the inner space of the deposition chamber at a level below the upper level of the inner space;

positioning a deposition substrate within the upper level of the inner space of the deposition chamber, the deposition substrate having an exposed surface, and wherein the exposed surface of the deposition substrate is positioned in the upper level of the inner space above the ejection orifice;

depositing the nanomaterial into the nanomaterial feeding container; and

feeding the nanomaterial into the nanomaterial mixing and ejection device wherein the nanomaterial is mixed and wherein after mixing, the nanomaterial is ejected into the inner space of the deposition chamber as particles comprising nanoparticles and nanomaterial clusters forming a suspension of nanoparticles in the upper level of the inner space wherein nanoparticles from the suspension of nanoparticles become deposited on the exposed surface of the deposition substrate such that nanoparticles are the primary particles deposited on the exposed surface of the deposition substrate and nanomaterial clusters primarily settle in the lower level of the inner space.

2. The method of claim 1 wherein the nanoparticles deposited onto the deposition substrate substantially have maximum dimensions of 1 μ

m.

3. The method of claim 1 wherein the nanoparticles deposited on the deposition substrate substantially have maximum dimensions of 100 nm.

4. The method of claim 1 wherein the nanoparticles deposited on the deposition substrate substantially have maximum dimensions of 50 nm.

5. The method of claim 1 wherein the nanoparticles deposited on the deposition substrate substantially have maximum dimensions of 10 nm.

6. The method of claim 1 wherein the nanomaterial comprises nanoclay particles, crystallites, ceramics, metals, metal oxides, dendritic polymers, nanopowders, nanofibers, nanospheres, and irregularly shaped granules.

7. The method of claim 1 wherein nanoparticles having maximum dimensions less than 1 μ

m comprise at least 50% of the particles deposited on the deposition substrate.

8. The method of claim 1 wherein nanoparticles having maximum dimensions less than 1 μ

m comprise at least 75% of the particles deposited on the deposition substrate.

9. The method of claim 1 wherein nanoparticles having maximum dimensions less than 1 μ

m comprise at least 90% of the particles deposited on the deposition substrate.

10. The method of claim 1 wherein nanoparticles having maximum dimensions less than 1 μ

m comprise at least 95% of the particles deposited on the deposition substrate.

11. The method of claim 1 wherein nanoparticles having maximum dimensions less than 1 μ

m comprise at least 99% of the particles deposited on the deposition substrate.

12. The method of claim 1 wherein the method is absent a use of electrical or magnetic energy directly applied to the nanomaterial or deposition substrate for enhancing separation of the nanoparticles of the nanomaterial or for enhancing deposition of the nanoparticles on the deposition substrate.

13. The method of claim 1 wherein all of or a portion of the deposition substrate is in a semi-solid, liquid, or molten condition.

14. The method of claim 1 wherein the nanomaterial is introduced into the deposition chamber through the ejection orifice via air, nitrogen, oxygen, carbon dioxide, carbon monoxide, argon, neon, helium, nitrogen, methane, ethylene, or mixtures thereof.

15. An apparatus for deposition of nanoparticles upon a deposition substrate, comprising:

a container assembly comprising;

a deposition chamber having an outer wall, an inner wall, an inner space, and upper end and a lower end, and the inner space having an upper level and a lower level positioned below the upper level;

a nanomaterial feeding container for containing a nanomaterial; and

a nanomaterial mixing and ejection device for mixing the nanomaterial from the nanomaterial feeding container and ejecting the mixed nanomaterial through an ejection orifice into the inner space of the deposition chamber at a level below the upper level of the inner space;

a deposition station for positioning a deposition substrate within the upper level of the inner space of the deposition chamber, the deposition substrate having an exposed surface, and wherein the exposed surface of the deposition substrate is positioned in the upper level of the inner space above the ejection orifice; and

wherein when the nanomaterial is deposited within the nanomaterial feeding container, the nanomaterial can be fed into the nanomaterial mixing and ejection device wherein the nanomaterial can be mixed and wherein after mixing, the nanomaterial can be ejected into the inner space of the deposition chamber as particles comprising nanoparticles and nanomaterial clusters forming a suspension of nanoparticles in the upper level of the inner space wherein nanoparticles from the suspension of nanoparticles become deposited on the exposed surface of the deposition substrate such that nanoparticles are the primary particles deposited on the exposed surface of the deposition substrate and nanomaterial clusters primarily settle in the lower level of the inner space.

16. The apparatus of claim 15 wherein the nanomaterial is separated substantially into smaller nanoparticles having maximum dimensions equal to or less than 1 μ

m and nanomaterial clusters having maximum dimensions greater than 1 μ

m.

17. The apparatus of claim 15 wherein the deposition substrate is supported within a deposition substrate container for holding the deposition substrate.

18. The apparatus of claim 17 wherein the deposition substrate container has a heating mechanism for heating the deposition substrate to a temperature for melting all or a portion of the deposition substrate.

19. The apparatus of claim 17 wherein deposition substrate can be continuously or intermittently added or removed from the deposition substrate container during ejection of nanomaterial into the deposition chamber.