Method for the preparation of Ag/C nanocomposite films by laser-induced carbonization of alkane

Patent metadata

Field	Value
Publication number	US-10125418-B2
Application number	US-201614990174-A
Country	US
Kind code	B2
Filing date	Jan 7, 2016
Priority date	Jan 30, 2015
Publication date	Nov 13, 2018
Grant date	Nov 13, 2018

Abstract

Ag/C crystalline nanocomposite films and a method of forming the films with controllable Ag/C molar ratios using a concurrent excimer laser-induced ablation of a silver target and a hydrocarbon gas under a vacuum atmosphere. Metal/Carbon nanocomposites prepared by concurrent irradiation of a metal target, in the presence of a hydrocarbon gas, during an excimer laser induced process.

First claim

The invention claimed is:

1. A method of preparing a core/shell nanocomposite thin film comprising:
concurrently irradiating a silver metal target and n-hexane gas, present within a deposition chamber, with an excimer laser beam;
wherein the irradiating forms carbon in the form of graphite from the n-hexane gas, and silver nanoparticles of said silver metal target which are spherical or cubic in form, thereby forming core/shell nanocomposite particles having a silver nanoparticle core covered by a graphite shell;
wherein the core/shell nanocomposite particles form a nanocomposite thin film on a substrate within the deposition chamber;
wherein the pressure of the n-hexane gas in the deposition chamber during the irradiating is within a range of 20-100 Pascal.

2. The method of claim 1 , which forms the nanocomposite thin film within 30-90 seconds.

3. The method of claim 1 , further comprising varying the pressure of the n-hexane gas to vary a mass ratio of carbon to metal in the core/shell nanocomposite particles.

4. The method of claim 1 , wherein the irradiating forms the core/shell nanocomposite particles having an average particle size of 5-20 nm in diameter.

5. The method of claim 1 , wherein the excimer laser beam is generated by an excimer laser selected from the group consisting of ArF and KrF excimer lasers having a beam wavelength of 193 nm-300 nm.

6. The method of claim 5 , wherein the excimer laser is an ArF excimer laser with a wavelength of 193 nm.

7. The method of claim 1 , wherein the core/shell nanocomposite particles have absorption peaks in a range from 417 nm-525 nm.

8. The method of claim 1 , wherein the nanocomposite thin film forms a coating for a biomedical device.

9. The method of claim 8 , wherein the biomedical device is a stent.

10. The method of claim 1 , wherein the core/shell nanocomposite thin film forms a coating for a solar light harvesting device or sensor.

11. The method of claim 1 , wherein the core/shell nanocomposite thin film is present on a surface of a water purification apparatus.

12. The method of claim 11 , wherein the water purification apparatus has a plasmonic photocatalysis surface.

13. The method of claim 11 , wherein the water purification apparatus includes a nanocomposite thin film surface-enhanced Raman spectroscopy sensor.

14. A method for forming a silver/carbon nanocomposite from a solid silver metal target during an excimer laser ablation process comprising:
providing a deposition chamber;
placing the solid silver metal target and a substrate within said deposition chamber;
establishing a vacuum level within said deposition chamber so as to achieve a reduced atmospheric pressure;
introducing n-hexane into said deposition chamber wherein said n-hexane is in a vapor phase due to the reduced atmospheric pressure and furthermore wherein said n-hexane vapor fills said deposition chamber and is in contact with said solid silver metal target;
focusing an excimer laser beam onto the solid silver metal target in contact with the n-hexane vapor at a power density high enough to release cubic or spherical uniformly-sized silver nanoparticles from the solid silver metal substrate;
concurrently irradiating said n-hexane vapor with the excimer laser beam at a power density high enough to cause decomposition of the n-hexane vapor;
said irradiation causing a carbonization, in the form of graphite, of said silver nanoparticles to form core/shell nanocomposite particles having a silver nanoparticle core covered by a graphite shell;
collecting said core/shell nanocomposite particles on said substrate to form a core/shell nanocomposite thin film;
wherein varying the chamber vacuum level results in fluctuation of the n-hexane vapor pressure in the range of 20-100 Pascal, affecting the ratio of carbon to silver in the silver/carbon nanocomposite, and resulting in deposition texture variations of the core/shell nanocomposite thin film.

Assignees

• Univ King Fahd Pet & Minerals

Inventors

• Gondal Mohammed Ashraf
• FAJGAR Radek
• Yamani Zain Hassan Abdallah
• Chang Xiaofeng

Classifications

• B22F1/16

  Metallic particles coated with a non-metal (coated with lubricating or binding agents or with organic material B22F1/10) · CPC title

• B22F1/054

  Nanosized particles · CPC title

• A61L2400/12

  Nanosized materials, e.g. nanofibres, nanoparticles, nanowires, nanotubes; Nanostructured surfaces · CPC title

• A61L2420/04

  Coatings containing a composite material such as inorganic/organic, i.e. material comprising different phases · CPC title

• C23C16/483

  using coherent light, UV to IR, e.g. lasers · CPC title