Process for preparing noble metal nanoparticles

• US 6,572,673 B2
• Filed: 06/08/2001
• Issued: 06/03/2003
• Est. Priority Date: 06/08/2001
• Status: Expired due to Fees

• Current Assignee: Chang CHUN Petrochemical Company Limited (C.C.P. Contact Probes Co., Ltd.)
• Original Assignee: Chang CHUN Petrochemical Company Limited (C.C.P. Contact Probes Co., Ltd.)
• Inventors: Lee, Chien-Liang, Wan, Chi-Chao
• Primary Examiner(s): WYSZOMIERSKI, GEORGE P
• Application Number:
  US09/876,093
• Publication Number:
  US 20020194958A1
• Time in Patent Office: 725 Days
• Field of Search: 753/43, 753/62, 753/69, 753/70, 753/71
• US Class Current: 75/362
• CPC Class Codes: B22F 1/0545 Dispersions or suspensions of nanosized particles
• CPC Class Codes: B22F 2998/00 Supplementary information concerning processes or compositions relating to powder metallurgy
• CPC Class Codes: B22F 9/24 starting from liquid metal compounds, e.g. solutions
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites

Abstract

A process for preparing metal nanoparticles, comprising reacting suitable metal salts and anionic surfactant containing an anionic group of carboxylic group (COO⁻), sulfate group (SO₄²⁻) or sulfonate group (SO₃²⁻) as reducing agent in water under reflux at a temperature of 50-140° C., such that under the reducing power of said anionic surfactant itself, the metal salts can be effectively reduced into metal nanoparticles having a uniform particle size and that the reaction will be not too fast, no large microparticle will be formed, the yield will not be lowered, and the nanoparticle thus prepared can be dispersed stably in polar and non-polar solvent.

Claims

1. A process for preparing metal nanoparticles, comprising reacting at least one noble metal salt and an anionic surfactant containing an anionic group selected from the group consisting of, carboxylic group (CO), sulfate group (SO₄²⁻

) and sulfonate group (SO₃²⁻

) as reducing agent in water under reflux at a temperature of 50-140°

C., such that under the reducing power of said anionic surfactant itself, the metal salt is effectively reduced into metal nanoparticles having a uniform particle size, and the nanoparticle thus prepared is capable of being dispersed stably in polar and non-polar solvents.

2. A process as claimed in claim 1, wherein said surfactant is selected from the group consisting of sodium n-tetradecyl sulfate, sodium dodecyl sulfate, sodium decyl sulfate, sodium n-nonyl sulfate and sodium n-octyl sulfate.

3. A process as claimed in claim 2, wherein said noble metal salts are selected from the group consisting of Pd(OAc)₂, PdCl₂N, H₂PtCl₆.H₂O, Ag(OAc)₂, Ag(NO)₃, and HAuCl₄.3H₂O.

4. A process as claimed in claim 3, wherein said noble metal salt is Pd(OAc)₂.

5. A process as claimed in claim 3, wherein said noble metal salt is PdCl₂N.

6. A process as claimed in claim 3, wherein said noble metal salt is H₂PtCl₆.H₂O.

7. A process as claimed in claim 3, wherein said noble metal salt is Ag(OAc)₂.

8. A process as claimed in claim 3, wherein said noble metal salt is Ag(NO)₃.

9. A process as claimed in claim 3, wherein said noble metal salt is HAuCl₄.3H₂O.

10. A process as claimed in claim 2, wherein said surfactant is sodium n-tetradecyl sulfate.

11. A process as claimed in claim 2, wherein said surfactant is sodium dodecyl sulfate.

12. A process as claimed in claim 11 wherein the noble metal salt is Pd(OAc)₂.

13. A process as claimed in claim 2, wherein said surfactant is sodium decyl sulfate.

14. A process as claimed in claim 2, wherein said surfactant is sodium n-nonyl sulfate.

15. A process as claimed in claim 2, wherein said surfactant is sodium n-octyl sulfate.

16. A process as claimed in claim 1, wherein said noble metal salts are selected from the group consisting of Pd(OAc)₂, PdCl₂N, H₂PtCl₆.H₂O, Ag(OAc)₂, Ag(NO)₃, and HAuCl₄.3H₂O.