Methods for producing silver nanoparticles

• US 9,005,663 B2
• Filed: 08/31/2004
• Issued: 04/14/2015
• Est. Priority Date: 08/31/2004
• Status: Active Grant

• Current Assignee: Curators of the University of Missouri (University of Missouri)
• Original Assignee: Curators of the University of Missouri (University of Missouri)
• Inventors: Raghuraman, Kannan, Katti, Kattesh K.
• Primary Examiner(s): Pak, John
• Assistant Examiner(s): Schlientz, Nathan W
• Application Number:
  US10/931,174
• Publication Number:
  US 20060045916A1
• Time in Patent Office: 3,878 Days
• Field of Search: 424/489, 424/618, 514/114, 514/784, 514/785, 514/788, 753/70
• US Class Current: 424/489
• CPC Class Codes: A61K 33/38 Silver; Compounds thereof
• CPC Class Codes: A61K 9/14 Particulate form, e.g. powders, Processes for size reducing of pure drugs or the resulting products, Pure drug nanoparticles microspheres A61K9/16; microcapsules A61K9/50; nanocapsules, nanoparticles of the matrix type A61K9/51
• CPC Class Codes: A61K 9/2018 Sugars, or sugar alcohols, e.g. lactose, mannitol; Derivatives thereof, e.g. polysorbates
• CPC Class Codes: A61K 9/2054 Cellulose; Cellulose derivatives, e.g. hydroxypropyl methylcellulose
• CPC Class Codes: A61K 9/209 containing drug in at least two layers or in the core and in at least one outer layer
• CPC Class Codes: B22F 1/0545 Dispersions or suspensions of nanosized particles
• 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
• CPC Class Codes: C22C 5/06 Alloys based on silver

Abstract

An exemplary embodiment of the invention is a method for making silver nanoparticles, and includes steps of reacting a silver salt with a phosphene amino acid to make silver nanoparticles. Exemplary phosphene amino acids include trimers, with a particular example being a trimeric amino acid conjugate containing one phosphene group. In an exemplary method of the invention, the silver nanoparticles may be produced in timer periods of less than about 30 minutes, and at temperatures of less than about 40° C. Other methods of the invention are directed to methods for stabilizing silver nanoparticles.

Claims

1. A method for producing silver nanoparticles, the method comprising the steps of:

providing a silver salt;

combining said silver salt with starch and at least one solvent;

providing a phosphine amino acid including three alanines bound to a phosphorous center via a NCH2 bond with the following chemical formula

2. The method of claim 1 wherein the step of reacting said silver salt with said phosphine amino acid to make silver nanoparticles is performed at a temperature of less than 40°

C.

3. The method of claim 1 wherein the step of reacting said silver salt with said phosphine amino acid to make silver nanoparticles is performed at a temperature of less than 30°

C.

4. The method of claim 1 wherein the step of reacting said silver salt with said phosphine amino acid to make silver nanoparticles is performed at room temperature.

5. The method of claim 1 wherein the step of reacting said silver salt with said phosphene amino acid converts at least 70% of the silver in said silver salt into said silver nanoparticles and is performed in a time period of less than 1 hour.

6. The method of claim 1 wherein the step of reacting said silver salt with said phosphine amino acid converts at least 70% of the silver in said silver salt into said silver nanoparticles and is performed in a time period of less than 30 mins and at room temperature.

7. The method of claim 6 wherein said time period is less than 5 minutes.

8. The method of claim 1 wherein the step of reacting said silver salt with said phosphine amino acid converts at least 98% of the silver in said silver salt into said silver nanoparticles and is performed in a time period of less than 30 mins.

9. The method of claim 1 wherein the step of reacting said silver salt with said phosphine amino acid creates silver nanoparticles at least 80% of which have a size between 10-20 nm.

10. The method of claim 1, wherein the step of providing a phosphine amino acid includes providing a greater amount of said phosphine amino acid if a relatively small silver nanoparticle size is desired, and providing a smaller amount of said phosphine amino acid if a relatively large silver nanoparticle size is desired.

11. The method of claim 1 wherein said silver salt comprises silver nitrate.

12. The method of claim 1 and further including the step of storing said silver nanoparticles for a period of at least 2 weeks without agglomeration of said nanoparticles.

13. The method of claim 12 wherein said period is at least 6 months.

14. The method of claim 1 wherein the method is carried out within a living organism.

15. The method of claim 14 wherein said living organism is a mammal.

16. The method of claim 14 wherein said living organism is a human being, and wherein the step of reacting a silver salt with a phosphine amino acid further includes introducing said silver salt and said phosphine amino acid to a selected area of said human being during a surgical procedure.

17. The method of claim 1 wherein the step of reacting said silver salt with said phosphine amino acid comprises reacting at least 1 mole of said phosphine amino acid per 3 moles of said silver salt.

18. The method of claim 1 wherein the step of reacting said silver salt with said phosphine amino acid comprises reacting at least 1 mole of said phosphine amino acid per 5 moles of said silver salt.

19. The method of claim 1 wherein the step of reacting said silver salt with said phosphine amino acid

to make silver nanoparticles is performed at a temperature of less than 30°

C. to convert at least 80% of said silver in said silver salt to the silver nanoparticles within 30 mins.

20. The method of claim 1, wherein said phosphine amino acid and said silver salt are reacted in the molar ratio 1:

5.

21. A method for producing silver nanoparticles, the method comprising the steps of:

providing a silver salt;

providing a phosphine amino acid, wherein said phosphine amino acid comprises;

22. The method of claim 21, wherein said phosphine amino acid and said silver salt are reacted in the molar ratio 1:

5.

23. A method for producing silver nanoparticles, the method comprising the steps of:

dissolving starch in water to form a starch solution;

dissolving in water to form a phosphine amino acid solution a trimeric amino acid conjugate containing three alanines bound to a phosphorous center via a NCH₂ bond with the following chemical structure;

24. The method of claim 23, wherein said phosphine amino acid and said silver salt are reacted in the molar ratio 1:

5.

25. A method for storing silver nanoparticles comprising the steps of:

providing silver nanoparticles;

providing a phosphine amino acid including three alanines bound to a phosphorous center via a NCH2 bond with the following chemical structure;

26. The method of claim 25 and further including the step of storing said silver naoparticles for a period of at least 2 weeks without agglomeration.