Methods for controlling metal nanostructures morphology

Abstract

Described herein are methods of controlling metal nanowire morphologies by adjusting the reaction conditions of a polyol synthesis. In particular, by purging the reaction with an inert gas, batch-to-batch consistency can be achieved.

1 . A method comprising:
 (a) providing a first plurality of metal nanowires having a target mean length, a target mean diameter, or a target yield, wherein the first plurality of metal nanowires are prepared in a first polyol solvent by a first polyol synthesis that includes purging with an inert gas for a first purging period, and wherein the first polyol solvent is provided from a first manufacturer lot; and   (b) providing a second plurality of metal nanowires having the target mean length, the target mean diameter, or the target yield, wherein the second plurality of metal nanowires are prepared in a second polyol solvent by a second polyol synthesis that includes purging with an inert gas for a second purging period, and wherein the second polyol solvent is chemically identical to the first polyol solvent and is provided from a second manufacturer lot,   wherein the first purging period differs from the second purging period.   
     
     
         2 . The method of  claim 1  wherein the first polyol synthesis and the second polyol synthesis are otherwise carried out in substantially the same conditions. 
     
     
         3 . The method of  claim 1  wherein providing the second plurality of metal nanowires having the target mean length, the target mean diameter, or the target yield includes selecting the second purging period by running one or more test polyol syntheses in the second polyol solvent; providing a mean length, a mean width or a yield for respective resulting metal nanowires of each test polyol synthesis; and identifying the second purging period as corresponding to the test polyol synthesis that produces metal nanowires having the target mean length, target mean width or the target yield. 
     
     
         4 . The method of  claim 3  wherein the test polyol synthesis is of a smaller reaction scale than that of the second polyol synthesis. 
     
     
         5 . The method of  claim 3  wherein the polyol solvent is ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, or glycerol. 
     
     
         6 . The method of  claim 5  wherein the capping reagent is poly(vinylpyrrolidone). 
     
     
         7 . The method of  claim 6  wherein the ionic additive provides a chloride ion. 
     
     
         8 . The method of  claim 7  wherein the ionic additive is a tetraalkylammonium chloride. 
     
     
         9 . The method of  claim 5  wherein the metal salt is a silver salt and the metal nanowires are silver nanowires. 
     
     
         10 . The method of  claim 1  wherein the target yield is at least 80%. 
     
     
         11 . The method of  claim 8  wherein the tetraalkylammonium chloride is tetrabutylammonium chloride.