Methods of preparing metal nanodendrimer structures

Patent metadata

Field	Value
Publication number	US-9518156-B2
Application number	US-201514604560-A
Country	US
Kind code	B2
Filing date	Jan 23, 2015
Priority date	Jan 23, 2015
Publication date	Dec 13, 2016
Grant date	Dec 13, 2016

Abstract

A method includes heating a sulfonated polyester resin in an organic-free solvent, adding a solution of silver (I) ion to the heated resin in water to form a mixture, reducing silver (I) to silver (0) by heating the mixture from about 65° C. to about 90° C., thereby forming an emulsion of composite particles comprising a sulfonated polyester matrix and a plurality of silver nanoparticles disposed within the sulfonated polyester matrix, and allowing the silver nanoparticles to agglomerate into a silver nanodendrite structure.

First claim

What is claimed is:

1. A method comprising:
heating a sulfonated polyester resin in an organic-free solvent;
adding a solution of silver (I) ion to the heated resin in water to form a mixture;
reducing silver (I) to silver(0) by heating the mixture from about 65° C. to about 90° C., thereby forming an emulsion of composite particles comprising a sulfonated polyester matrix and a plurality of silver nanoparticles disposed within the sulfonated polyester matrix; and
allowing the silver nanoparticles to agglomerate into a silver nanodendrite structure.

2. The method of claim 1 , wherein heating the sulfonated polyester resin is conducted at a temperature from about 65° C. to about 90° C.

3. The method of claim 1 , wherein the organic-free solvent is de-ionized water.

4. The method of claim 1 , wherein allowing the silver nanoparticles to agglomerate comprises leaving the emulsion to sit unstirred at ambient temperature for at least about one week.

5. The method of claim 1 , wherein a source of silver (I) ion is selected from silver nitrate, silver sulfonate, silver fluoride, silver perchlorate, silver lactate, silver tetrafluoroborate, silver oxide and silver acetate.

6. The method of claim 1 , wherein a concentration of silver ion after addition is a non-zero amount up to about 1 percent by weight of the solution or less.

7. The method of claim 1 , wherein reducing silver (I) to silver(0) further comprises adding ascorbic acid or trisodium citrate as a reducing agent.

8. The method of claim 1 , wherein the sulfonated polyester resin is a branched polymer.

9. The method of claim 1 , wherein the sulfonated polyester matrix is a lithium, potassium, or sodium salt of a polymer selected from the group consisting of poly(1,2-propylene-5-sulfoisophthalate), poly(neopentylene-5-sulfoisophthalate), poly(diethylene-5-sulfoisophthalate), copoly-(1,2-propylene-5-sulfoisophthalate)-copoly-(1,2-propylene-terphthalate), copoly-(1,2-propylenediethylene-5-sulfoisophthalate)-copoly-(1,2-propylene-diethylene-terephthalatephthalate), copoly(ethylene-neopentylene-5-sulfoisophthalate)-copoly-(ethylene-neopentylene-terephthalatephthalate), and copoly(propoxylated bisphenol A)-copoly-(propoxylated bisphenol A-5-sulfoisophthalate).

10. The method of claim 1 , wherein the sulfonated polyester resin comprises a polyol monomer unit selected from the group consisting of trimethylolpropane, 1,2-propanediol, diethylene glycol, and combinations thereof.

11. The method of claim 1 , wherein the sulfonated polyester resin comprises a diacid monomer unit selected from the group consisting of terephthalic acid, sulfonated isophthalic acid, and combinations thereof.

12. The method of claim 1 , wherein an amount of the sulfonated polyester resin is in a range from about 0.05 percent by weight of the mixture to about 50 percent by weight of the mixture.

13. The method of claim 1 , wherein the method is conducted in the absence of a surfactant.

14. A method comprising:
heating a branched sulfonated polyester resin in de-ionized water;
adding a solution of silver (I) ion to the heated resin in water to form a mixture, wherein silver (I) ion is present in a non-zero amount up to about 1 percent by weight of the mixture;
reducing silver (I) to silver(0) by heating the mixture from about 65° C. to about 90° C., thereby forming an emulsion of composite particles comprising a sulfonated polyester matrix and a plurality of silver nanoparticles disposed within the sulfonated polyester matrix; and
allowing the silver nanoparticles to agglomerate into a silver nanodendrite structure by leaving the emulsion to sit at ambient temperature for at least one week.

15. The method of claim 14 , wherein the ratio of the concentration of silver (I) ion to branched sulfonated polyester resin is in a range from about 1:1 to about 1:120.

16. The methods of claim 14 , wherein the silver nanodendrite forms after about three weeks.

17. The method of claim 14 , wherein the method is carried out in the absence of a surfactant.

Assignees

• Xerox Corp

Inventors

• Farrugia Valerie M
• Desouza Alana
• Gardner Sandra J

Classifications

• C08K2003/0806

  Silver · CPC title

• C08K3/08

  Metals · CPC title

• C08K2201/011

  Nanostructured additives · CPC title

• C08K3/28

  Nitrogen-containing compounds · CPC title

• C08J3/212 Primary

  and solid additives · CPC title