NANOPARTICLE PRODUCTION IN LIQUID WITH MULTIPLE-PULSE ULTRAFAST LASER ABLATION

• US 20110192714A1
• Filed: 11/22/2010
• Published: 08/11/2011
• Est. Priority Date: 02/10/2010
• Status: Active Grant

• Current Assignee: IMRA America Incorporated (Aisin Corp.)
• Original Assignee: IMRA America Incorporated (Aisin Corp.)
• Inventors: Che, Yong, Hu, Zhendong, LIU, Bing
• Granted Patent: US 8,858,676 B2
• Time in Patent Office: Days
• US Class Current: 204/157.41
• CPC Class Codes: B01J 19/121 Coherent waves, e.g. laser beams lasers per se H01S3/00
• CPC Class Codes: B22F 1/054 Nanosized particles
• CPC Class Codes: B22F 2202/11 Use of irradiation
• CPC Class Codes: B22F 2999/00 Aspects linked to processes or compositions used in powder metallurgy
• CPC Class Codes: B22F 9/04 starting from solid material, e.g. by crushing, grinding or milling C22C1/1084 takes precedence; crushing, grinding or milling, in general, see the relevant subclasses, e.g. B02C
• CPC Class Codes: Y10S 977/889 by laser ablation

Abstract

A method for generating nanoparticles in a liquid comprises generating groups of ultrafast laser pulses, each pulse in a group having a pulse duration of from 10 femtoseconds to 200 picoseconds, and each group containing a plurality of pulses with a pulse separation of 1 to 100 nanoseconds and directing the groups of pulses at a target material in a liquid to ablate it. The multiple pulse group ablation produces nanoparticles with a reduced average size, a narrow size distribution, and improved production efficiency compared to prior pulsed ablation systems.

Claims

1. A method of producing nanoparticle solutions by laser ablation, comprising:

generating a plurality of groups of laser pulses, each of said groups containing 2 to 50 laser pulses; and

irradiating a target material with said pulses, said target material being disposed in a liquid.

2. The method of claim 1, wherein a group repetition rate comprises from 100 to 500 kHz.

3. The method of claim 1, wherein said plurality of groups of laser pulses comprises from 2 to 10 pulses per group.

4. The method of claim 1, wherein a time separation between consecutive pulses within each of said groups is from 1 to 100 nanoseconds.

5. The method of claim 4, wherein said time separation between consecutive pulses within each of said groups is from 10 to 30 nanoseconds.

6. The method of claim 1, wherein a time separation between consecutive groups is from 0.1 to 10 microseconds.

7. The method of claim 1, wherein a pulse duration is from 10 femtoseconds to 200 picoseconds.

8. The method of claim 1, wherein at least one of said pulses has a pulse energy of from 100 nanoJoules to 1 milliJoules.

9. The method of claim 8, wherein at least one of said pulses has a pulse energy of from 1 microJoules to 10 microJoules.

10. The method of claim 8, wherein at least one of said pulses has a wavelength in one of the spectral regions of UV, visible, and near infrared.

11. The method of claim 1, wherein said target material comprises gold, silver, copper, platinum, palladium, or another metal material.

12. The method of claim 11, wherein said target material comprises a binary or a ternary alloy comprising gold, silver, copper, platinum, palladium, or another metal material.

13. The method of claim 1, wherein said target material comprises a semiconductor, a metal oxide, or a glass.

14. The method of claim 1, wherein said liquid comprises de-ionized water.

15. The method of claim 14, wherein said de-ionized water has a resistance greater than 0.05 M Ohm·

cm.

16. The method of claim 1, wherein said pulses are guided to said target material by a vibration mirror.

17. The method of claim 16, wherein said vibration mirror has a frequency greater than 10 Hz and an angular amplitude greater than 0.1 mrad.

18. The method of claim 16, wherein said vibration mirror guides movement of said pulses on said target material such that a focal spot of said pulses moves at a speed of greater than 0.1 meters per second across said target material.

19. A method of producing nanoparticle solutions by laser ablation, comprising:

generating a plurality of groups of laser pulses, each of said groups containing 2 to 50 laser pulses with a group repetition rate of 100 to 500 kHz and a time separation between consecutive pulses within each of said groups of from 1 to 100 nanoseconds; and

irradiating a target material with said pulses, said target material being disposed in a liquid.

20. The method of claim 19, wherein a pulse duration is from 10 femtoseconds to 200 picoseconds.

21. The method of claim 19, wherein at least one of said pulses has a pulse energy of from 100 nanoJoules to 1 milliJoules.

22. The method of claim 19, wherein said target material comprises gold, silver, copper, platinum, palladium, or another metal material.

23. The method of claim 19, wherein said liquid comprises de-ionized water having a resistance greater than 0.05 M Ohm·

cm.

24. The method of claim 19, wherein said pulses are guided to said target material by a vibration mirror;

and wherein said vibration mirror guides movement of said pulses on said target material such that a focal spot of said pulses moves at a speed of greater than 0.1 meters per second across said target material.