Preparation of nanoparticles

Abstract

A method of preparing a nanoparticle having a particle size of 1 nm to 1 μm, said method comprising continuously supplying a solution containing a particle-forming precursor into a micro channel having a diameter of 1 μm to 1 mm, said micro channel being disposed in a heating zone. The solution is heated rapidly up to a reaction initiation temperature to cause a reaction in said solution. The solution is rapidly cooled to prepare the nanoparticle.

What is claimed is:  
     
         1 . A method of preparing a nanoparticle having a particle size of 1 nm to 1 μm, said method comprising: 
 continuously supplying a solution containing a particle-forming precursor into a micro channel having a diameter of 1 μm to 1 mm, said micro channel being disposed in a heating zone;  
 heating said solution rapidly up to a reaction initiation temperature to cause a reaction in said solution; and  
 rapidly cooling said solution to prepare the nanoparticle.  
 
     
     
         2 . The method of  claim 1 , wherein the heating temperature and the residence time of said particle-forming precursor solution in said heating zone are adjusted to control a particle size of the nanoparticle.  
     
     
         3 . The method of  claim 1 , wherein the reaction is performed while agitating said particle-forming precursor solution.  
     
     
         4 . The method of  claim 3 , wherein said particle-forming precursor solution is agitated by means of ultrasound.  
     
     
         5 . The method of  claim 1 , wherein said particle-forming precursor solution includes a first solution and a second solution adapted to form different phases, respectively, wherein said first and second solutions are reacted with one another along an interface therebetween.  
     
     
         6 . The method of  claim 1 , wherein said particle-forming precursor solution is injected with a fluid for segmenting said solution to control the residence-time distribution of said solution.  
     
     
         7 . The method of  claim 1 , wherein a concentration of the precursor is 0.001-5% by mass.  
     
     
         8 . The method of  claim 1 , wherein a concentration of the precursor is 0.01-5% by mass.  
     
     
         9 . The method of  claim 1 , wherein a solvent in the solution, is selected from a group consisting of water, an organic solvent, methyl alcohol, ethyl alcohol, acetone, dimethylformamide, dimethylacetamide, dimethyl sulfoxide, octane, cyclohexane, benzene, xylene, diethyl ether and acetic ether.  
     
     
         10 . The method of  claim 1 , wherein the nanoparticle is made of a material selected from a group consisting of gold, silver, palladium, cobalt, nickel, a metalloid, silicon, germanium, a metalloid oxide, zinc oxide, silicon oxide, germanium oxide, a metal chalcogenide compound, cadmium selenide, cadmium sulfide, zinc sulfide, an organic complex compound and an organic pigment.  
     
     
         11 . The method of  claim 2 , wherein the residence time in the micro channel is controlled by adjusting a feeding rate of the solution.  
     
     
         12 . The method of  claim 2 , wherein the residence time in the micro channel is controlled by adjusting a volume of the micro channel.  
     
     
         13 . The method of  claim 6 , wherein the fluid is selected from a group consisting of nitrogen, argon, helium, air, oxygen, hydrogen, ammonia, hexane, cyclohexane, toluene, water, methyl alcohol, ethyl alcohol, dimethyl sulfoxide and dimethylformamide.  
     
     
         14 . An apparatus for producing a nanoparticle, the apparatus comprising: 
 a micro channel with a diameter of 1 μm to 1 mm, with at least one source of input for    a solution containing a particle-forming precursor;    a heating zone for heating the micro channel, where the solution can be heated rapidly to a reaction initiation temperature; and    a collection vessel for collecting a reaction product.    
     
     
         15 . The apparatus of  claim 14 , wherein the micro channel is a capillary tube.  
     
     
         16 . The apparatus of  claim 15 , wherein the capillary tube is made using a material selected from a group consisting of glass, metal, alloy, a plastic, polyolefin, polyvinyl chloride, polyamide, polyester and fluororesin.  
     
     
         17 . The apparatus of  claim 14 , wherein the micro channel is provided by a groove on a layer, said layer being on a heat resistant substrate.  
     
     
         18 . The apparatus of  claim 17 , wherein the layer is made of a material selected from a group consisting of a metal oxide, silica, alumina, titania, a heat-resistant plastic, and fluorinated resin.  
     
     
         19 . The apparatus of  claim 17 , wherein the heat-resistant substrate is a metal or an alloy.  
     
     
         20 . The apparatus of  claim 14  wherein the heating zone is made of a heat plate, an oil bath, an infrared heater or a high frequency heater.