Metal nanoparticles and method for manufacturing thereof

Abstract

The present invention provides a method of producing metal nanoparticles, having a high yield rate and uniform size achieved by employing a heterologous reducing agent that considerably reduces unreactant, and using ethylene glycol that allows effective separation of desired metal nanoparticles. In addition, the present invention provides metal nanoparticles having high dispersion stability achieved by capping with polyvinyl pyrrolidone(PVP) and conductive ink including these metal nanoparticles. One aspect of the invention may provide a method of producing nanoparticles comprising, (a) mixing ethylene glycol, capping molecules and a reducing agent, (b) mixing a metal precursor with alcohol-based compound and reacting it with the mixture of (a), and (c) finishing the reaction by adding acetone and ethylene glycol to the reaction solution (b).

1 . A method of producing metal nanoparticles, said method comprising: 
 (a) mixing ethylene glycol, capping molecules and a reducing agent;    (b) reacting a mixture of a metal precursor and an alcohol-based compound with the mixture in the step (a); and    (c) adding acetone and ethylene glycol to the reacting solution in the step (b).    
     
     
         2 . The method of  claim 1 , wherein the mixture in the step (a) is heated to a temperature of 100-140° C. before the step (b).  
     
     
         3 . The method of  claim 1 , wherein the ethylene glycol in the step (a) is mixed in 100 to 200 parts by weight with respect to 10 parts by weight of the metal precursor.  
     
     
         4 . The method of  claim 1 , wherein in the step of (b), the mixture of the metal precursor and the alcohol-based compound and the mixture in the step (a) are added together within a short period of time to react.  
     
     
         5 . The method of  claim 1 , wherein recovering metal nanoparticles by centrifuging the solution after the step of (c) is further included.  
     
     
         6 . The method of  claim 1 , wherein the capping molecule is polyvinyl pyrrolidone.  
     
     
         7 . The method of  claim 6 , wherein the polyvinyl pyrrolidone is mixed in 30-70 parts by weight with respect to 10 parts by weight of the metal precursor.  
     
     
         8 . The method of  claim 1 , wherein the reducing agent includes one or more compounds selected from the group consisting of glucose, ascorbic acid, tannic acid, dimethylformamide, tetrabutyl ammonium borohydride, NaBH 4 , LiBH 4  and N 2 H 4 .  
     
     
         9 . The method of  claim 8 , wherein the reducing agent is glucose.  
     
     
         10 . The method of  claim 1 , wherein the reducing agent is mixed in a mole ratio of 0.2 to 0.5 with respect to the metal precursor.  
     
     
         11 . The method of  claim 1 , wherein the metal precursor includes one or more metals selected from the group consisting of gold, silver, copper, nickel, zinc, platinum, palladium, rhodium, ruthenium, iridium, osmium, tungsten, tantalum, titanium, aluminum, cobalt, iron and a mixture thereof.  
     
     
         12 . The method of  claim 1 , wherein the metal precursor is one or more compound selected from the group consisting of AgNO 3 , AgBF 4 , AgPF 6 , Ag 2 O, CH 3 COOAg, AgCF 3 SO 3 , AgClO 4 , AgCl, and CH 3 COCH═COCH 3 Ag.  
     
     
         13 . The method of  claim 1 , wherein the alcohol-based compound is one or more compounds selected from the group consisting of methanol, ethanol, ethylene glycol and diethylene glycol.  
     
     
         14 . The method of  claim 1 , wherein the alcohol-based compound is mixed in 30-50 parts by weight with respect to 10 parts by weight of the metal precursor.  
     
     
         15 . The method of  claim 1 , wherein the ethylene glycol in the step (c) is added in 2-10 parts by weight with respect to 1 part by weight of the capping molecule.  
     
     
         16 . The method of  claim 1 , wherein the reaction time of the step (b) ranges from 30 minutes to 4 hours.  
     
     
         17 . Metal nanoparticles produced by a method of  claim 1 .  
     
     
         18 . The metal nanoparticles of  claim 17 , wherein the metal nanoparticles are capped with polyvinyl pyrrolidone.  
     
     
         19 . The metal nanoparticles of  claim 18 , wherein the particles of the polyvinyl pyrrolidone are 5-10 weight %.  
     
     
         20 . Conductive ink including metal nanoparticles according to  claim 17.