Methods of controlling nanostructure formations and shapes
View Patent ↗A method of forming monodispersed metal nanowires comprising: forming a reaction mixture including a metal salt, a capping agent and a quaternary ammonium chloride in a reducing solvent at a first temperature; and forming metal nanowires by reducing the metal salt in the reaction mixture.
1. A method of forming monodispersed metal nanowires comprising:
forming a reaction mixture including a metal salt, a capping agent and a quaternary ammonium chloride in a reducing solvent, wherein a molar ratio of the quaternary ammonium chloride and the metal salt is between about 0.001 and 0.1; and,
allowing the reaction mixture to react in a sufficient period of time and at a sufficient temperature to reduce the metal salt to monodispersed metal nanowires.
2. The method of claim 1 wherein the metal salt is silver nitrate, silver acetate, silver perchlorate, gold perchlorate, palladium chloride, or platinum chloride.
3. The method of claim 1 wherein the quaternary ammonium chloride is represented by formula NR 4 + Cl − , each R being the same or different and independently an alkyl, alkenyl, alkynyl, aryl, or aralkyl.
4. The method of claim 3 wherein each R is the same or different and independently methyl, butyl, octyl, decyl or cetyl.
5. The method of claim 4 wherein the quaternary ammonium chloride is tetramethylammonium chloride, tetrabutylammonium chloride , cetyl trimethylammonium chloride, C 8 -C 18 alkyl dimethyl benzyl ammonium chloride, or methyl trioctylammonium chloride.
6. The method of claim 1 wherein the capping agent is poly(vinyl pyrrolidone), polyacrylamide, polyacrylic or a copolymer thereof.
7. The method of claim 1 wherein the reducing solvent includes at least two hydroxyl groups.
8. The method of claim 7 wherein the reducing solvent is ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, glycerin, glycerol, or glucose.
9. The method of claim 1 wherein the reaction mixture is formed at a first temperature of about 20° C. to about 40° C.
10. The method of claim 1 wherein the reducing is carried out at a second temperature of about 50° C. to about 170° C.
11. The method of claim 1 wherein the metal salt is silver nitrate and silver nanowires are formed.
12. The method of claim 11 wherein the silver nanowires have a mean diameter of 75±8 nm, and an average length of 9.7±2.6 μm.
13. The method of claim 1 wherein the reaction mixture includes silver nitrate, poly(vinyl pyrrolidone), tetrabutylammonium chloride and ethylene glycol.
14. The method of claim 1 wherein the monodispersed metal nanowires have aspect ratios of greater than 100.
15. The method of claim 1 wherein the sufficient temperature is below 100° C.
16. A method of forming metal nanowires comprising:
forming a reaction mixture including a metal salt, a capping agent selected from poly(vinyl pyrrolidone), polyacrylamide, polyacrylic and copolymers thereof, and a quaternary ammonium chloride in a reducing solvent, wherein a molar ratio of the quaternary ammonium chloride and the metal salt is between about 0.001 and 0.1; and
forming metal nanowires by reducing the metal salt.
17. The method of claim 16 wherein the metal salt is a silver salt.
18. The method of claim 17 wherein forming metal nanowires comprises forming silver nanowires having aspect ratios of greater than 100.