Processes for making silver nanostructures

Patent metadata

Field	Value
Publication number	US-2016325352-A1
Application number	US-201415109257-A
Country	US
Kind code	A1
Filing date	Dec 15, 2014
Priority date	Dec 31, 2013
Publication date	Nov 10, 2016
Grant date	—

Abstract

The present invention is directed to a process for making silver nanostructures, comprising reacting at least one polyol and at least one silver compound that is capable of producing silver metal when reduced, in the presence of a source of chloride or bromide ions, at least one copolymer, and at least one acid scavenger. The present invention is also directed to silver nanostructures made by the processes described herein.

First claim

1 . A process for making silver nanostructures, the process comprising reacting at least one polyol and at least one silver compound that is capable of producing silver metal when reduced, in the presence of:
(a) a source of chloride or bromide ions, and (b) at least one copolymer that comprises:
(i) one or more first constitutional repeating units that each independently comprise at least one pendant saturated or unsaturated, five-, six-, or seven-membered, acylamino- or diacylamino-containing heterocylic ring moiety per constitutional repeating unit, and
(ii) one or more second constitutional repeating units, each of which independently differs from the one or more first nonionic constitutional repeating units, and has a molecular weight of greater than or equal to about 500 grams per mole; and
(c) at least one acid scavenger.

2 . The process of claim 1 , wherein the first constitutional repeating units of the copolymer each independently comprise a pyrrolidonyl moiety or a pyrrolidinedionyl moiety and the second constitutional repeating units of the copolymer each independently comprise a cationic moiety.

3 . (canceled)

4 . (canceled)

5 . The process of claim 1 , wherein the copolymer is a random copolymer made by free radical polymerization of a monomer mixture comprising from about 80 to less than 100 parts by weight of vinyl pyrrolidone and from greater than 0 to about 20 parts by weigh of a diallyldimethylammonium salt.

6 . The process of claim 1 , wherein the at least one silver compound comprises silver nitrate, the at least one polyol comprises ethylene glycol or glycerol, the at least one acid scavenger comprises LiOH, Na 2 S, Ca(OH) 2 , bicine, or a mixture thereof, the total amount of silver nitrate added to the reaction mixture is from 1.5×10 −3 mole to about 1 mole silver nitrate per Liter of reaction mixture, and the reaction is conducted in the presence of, based on the weight of the reaction mixture, from about 0.01 wt % to about 50 wt % of the copolymer.

7 . The process of claim 1 , wherein the acid scavenger comprises a base, a buffering agent, or a mixture thereof.

8 . The process of claim 7 , wherein the acid scavenger comprises a base.

9 . The process of claim 8 , wherein the base comprises a source of hydroxide ions, a source of sulfide ions, or a mixture thereof.

10 .- 15 . (canceled)

16 . The process of claim 7 , wherein the acid scavenger comprises a buffering agent.

17 .- 24 . (canceled)

25 . A process for making silver nanostructures, the process comprising:
(1) heating to a first temperature a mixture comprising
(a) at least one polyol;
(b) a source of chloride or bromide ions;
(c) at least one copolymer that comprises:
(i) one or more first constitutional repeating units that each independently comprise at least one pendant saturated or unsaturated, five-, six-, or seven-membered, acylamino- or diacylamino-containing heterocylic ring moiety per constitutional repeating unit, and
(ii) one or more second constitutional repeating units, each of which independently differs from the one or more first nonionic constitutional repeating units,

and has a molecular weight of greater than or equal to about 500 grams per mole, and
(2) adding to the mixture of step (1) at least one silver compound that is capable of producing silver metal when reduced; and (3) heating to a second temperature the mixture obtained in step (2);
thereby making silver nanostructures.

26 . The process of claim 25 , wherein the mixture of step (1) further comprises at least one acid scavenger.

27 . The process of claim 25 , wherein the first temperature is from about 130° C. to about 155° C.

28 . The process of claim 25 , wherein the second temperature is from about 160° C. to about 185° C.

29 . The process of claim 25 , wherein the first constitutional repeating units of the copolymer each independently comprise a pyrrolidonyl moiety or a pyrrolidinedionyl moiety and the second constitutional repeating units of the copolymer each independently comprise a cationic moiety.

30 . (canceled)

31 . (canceled)

32 . The process of claim 25 , wherein the copolymer is a random copolymer made by free radical polymerization of a monomer mixture comprising from about 80 to less than 100 parts by weight of vinyl pyrrolidone and from greater than 0 to about 20 parts by weigh of a diallyldimethylammonium salt.

33 . The process of claim 26 , wherein the at least one silver compound comprises silver nitrate, the at least one polyol comprises ethylene glycol or glycerol, the at least one acid scavenger comprises LiOH, Na 2 S, Ca(OH) 2 , bicine, or a mixture thereof, the total amount of silver nitrate added to the reaction mixture is from 1.5×10 −3 mole to about 1 mole silver nitrate per Liter of reaction mixture, and the reaction is conducted in the presence of, based on the weight of the reaction mixture, from about 0.01 wt % to about 50 wt % of the copolymer.

34 . The process of claim 26 , wherein the acid scavenger comprises a base, a buffering agent, or a mixture thereof.

35 . The process of claim 26 , wherein the acid scavenger comprises a base.

36 . The process of claim 35 , wherein the base comprises a source of hydroxide ions, a source of sulfide ions, or a mixture thereof.

37 .- 52 . (canceled)

53 . A dispersion comprising:
(A) silver nanostructures made according to the process of claim 1 or 25 ; and (B) a liquid medium; wherein the liquid medium comprises water, a (C 1 -C 6 )alkanol, or a mixture thereof.

54 . An electrically conductive coating made according to a process comprising the steps of:
(A) depositing on a substrate a layer of a dispersion according to claim 53 , and (B) removing the liquid medium from the layer.

55 . (canceled)

Assignees

• Rhodia Operations

Inventors

• Alsayed Ahmed
• Ahmed Adham
• Badre Chantal
• Hough Lawrence Alan
• Burel Celine Anna Simone

Classifications

• B22F1/0547

  Nanofibres or nanotubes · CPC title

• B22F1/0545

  Dispersions or suspensions of nanosized particles · CPC title

• B82Y40/00

  Manufacture or treatment of nanostructures · CPC title

• B22F9/24 Primary

  starting from liquid metal compounds, e.g. solutions · CPC title

• B22F2009/165

  Chemical reaction in an Ionic Liquid [IL] (B22F2009/245 takes precedence) · CPC title