Methods of controlling nanostructure formations and shapes
A method of forming monodispersed metal nanowires comprising: forming a reaction mixture including a metal salt, a capping agent and a ionic additive 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 comprising a metal salt, a capping agent and an ionic additive in a reducing solvent, wherein a molar ratio of the ionic additive and the metal salt is between about 0.001 and about 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 the 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 ionic additive comprises an anion selected from the group consisting of chloride, iodide, fluoride, phosphate, sulfate, hydrogen sulfate, and sulfonate.
4. The method of claim 1 wherein the ionic additive is HCl, ZnCl 2 , or MgCl 2 .
5. The method of claim 1 , wherein the molar ratio of the ionic additive and the metal salt is about 0.1.
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 capping agent is poly(vinyl pyrrolidone) having a molecular weight of 50,000.
8. The method of claim 1 , wherein the reducing solvent comprises at least two hydroxyl groups.
9. The method of claim 1 , wherein the reducing solvent is ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, glycerin, glycerol, or glucose.
10. The method of claim 1 , wherein the reaction mixture is formed at a first temperature of about 20° C. to about 40° C.
11. The method of claim 1 , wherein the reducing is carried out at a second temperature of about 50° C. to about 170° C.
12. The method of claim 1 , wherein the metal salt is silver nitrate, and silver nanowires are formed.
13. The method of claim 12 , wherein the silver nanowires have a mean diameter of 75±8 nm, and an average length of 9.7±2.6 μm.
14. The method of claim 1 , wherein the reaction mixture comprises silver nitrate, poly(vinyl pyrrolidone), tetrabutylammonium chloride and ethylene glycol.
15. The method of claim 1 , wherein the monodispersed metal nanowires have aspect ratios of greater than 100.
16. The method of claim 1 , wherein the sufficient temperature is below 100° C.