Method of forming carbon nanotubes

Abstract

Provided is a method of forming carbon nanotubes. The method includes modifying the surfaces of catalyst nano particles using a surface modifying agent containing silicon such as 3-aminopropyltriethoxysilane, and growing the carbon nanotubes on the modified surfaces of the catalyst nano particles so that the diameter of the carbon nanotubes is controlled by the surface modification. The diameter of the carbon nanotubes is controlled by surface steric stabilization resulting from a silicon oxide deposit deposited on the surfaces of the catalyst nano particles through the decomposition of the surface modifying agent.

1 . A method of forming carbon nanotubes, the method comprising: 
 modifying the surfaces of catalyst nano particles using a surface modifying agent containing silicon; and    growing the carbon nanotubes on the modified surfaces of the catalyst nano particles so that the diameter of the carbon nanotubes is controlled by the surface modification.    
   
   
       2 . The method of  claim 1 , wherein the catalyst nano particles include transition metal nano particles having a particle size distribution with a standard deviation of approximately 15% using a wet chemical synthetic method.  
   
   
       3 . The method of  claim 1 , wherein the surface modifying agent comprises a functional group chosen from a silane group, a siloxane group, and a silsesquioxane group.  
   
   
       4 . The method of  claim 1 , wherein the surface modifying agent comprises a functional group chosen from —NH 2 , —COOH, —CONH 2 , and —SH.  
   
   
       5 . The method of  claim 1 , wherein the surface modifying agent comprises 3-aminopropyltriethoxysilane.  
   
   
       6 . The method of  claim 1 , wherein the modifying of the surfaces of the catalyst nano particles with the surface modifying agent comprises: 
 preparing a nano particle dispersion solution in which the catalyst nano particles are dispersed; and    adding the surface modifying agent to the nano particle dispersion solution directly or after being dissolved in a solution.    
   
   
       7 . The method of  claim 1 , wherein the growing of the carbon nanotubes comprises performing chemical vapor deposition by supplying a carbon source gas over the catalyst nano particles and decomposing the carbon source gas to synthesize the carbon nanotubes.  
   
   
       8 . The method of  claim 7 , wherein the chemical vapor deposition is thermal chemical vapor deposition in which the carbon source gas is thermally decomposed or plasma enhanced chemical vapor deposition, in which the carbon source gas is decomposed by plasma.  
   
   
       9 . The method of  claim 1 , wherein the diameters of the carbon nanotubes is controlled by surface steric stabilization resulting from a silicon oxide deposit deposited on the surfaces of the catalyst nano particles through the decomposition of the surface modifying agent.  
   
   
       10 . A method of forming carbon nanotubes, the method comprising: 
 dispersing catalyst nano particles in a solvent to obtain nano particle dispersion;    modifying the surfaces of the catalyst nano particles in the nano particle dispersion by adding a surface modifying agent containing silicon to the nano particle dispersion;    coating the nano particle dispersion on a substrate; and    growing the carbon nanotubes on the catalyst nano particles coated on the substrate so that the diameter of the carbon nanotubes is controlled by the surface modification.    
   
   
       11 . The method of  claim 10 , wherein the solvent includes at least one of n-hexane, chloroform, toluene, water, and ethanol.  
   
   
       12 . The method of  claim 10 , wherein the surface modifying agent comprises a functional group chosen from a silane group, a siloxane group, and a silsesquioxane group.  
   
   
       13 . The method of  claim 10 , wherein the surface modifying agent comprises a functional group chosen from —NH 2 , —COOH, —CONH 2 , and —SH.  
   
   
       14 . The method of  claim 10 , wherein the coating of the nano particle dispersion on the substrate is performed using a coating method selected from at least one of a spin coating, a dip coating, a puddle coating, and a spray coating.  
   
   
       15 . The method of  claim 10 , wherein the substrate is a glass substrate, a silicon substrate, or a substrate having a layer that comprises a conductive material chosen from Au, Ag, ITO, TiN, and TaN.  
   
   
       16 . The method of  claim 10 , wherein the diameter of the growing carbon nanotubes is controlled by surface steric stabilization resulting from a silicon oxide deposit deposited on the surfaces of the catalyst nano particles through the decomposition of the surface modifying agent.  
   
   
       17 . A method of forming carbon nanotubes, the method comprising: 
 dispersing catalyst nano particles in a solvent to obtain nano particle dispersion;    modifying the surfaces of the catalyst nano particles in the nano particle dispersion by adding a surface modifying agent containing silicon and an amine functional group to the nano particle dispersion;    coating the nano particle dispersion on a substrate; and    growing the carbon nanotubes on the catalyst nano particles coated on the substrate so that the diameter of the carbon nanotubes is controlled by the surface modification.    
   
   
       18 . The method of  claim 17 , wherein the surface modifying agent comprises 3-aminopropyltriethoxysilane.  
   
   
       19 . The method of  claim 17 , wherein the surface modifying agent comprises a functional group chosen from a silane group, a siloxane group, and a silsesquioxane group.  
   
   
       20 . The method of  claim 17 , wherein the diameter of the growing carbon nanotubes is controlled by surface steric stabilization resulting from a silicon oxide deposit deposited on the surfaces of the catalyst nano particles through the decomposition of the surface modifying agent.  
   
   
       21 . A method of forming carbon nanotubes, the method comprising: 
 providing catalyst nano particles;    treating surfaces of catalyst nano particles with a surface modifying agent containing silicon; and    growing the carbon nanotubes on the surfaces of the catalyst nano particles treated with the surface modifying agent containing silicon.    
   
   
       22 . The method of  claim 21 , wherein a diameter of the carbon nanotubes is controlled by treating the surfaces of catalyst nano particles.  
   
   
       23 . The method of  claim 21 , wherein the catalyst nano particles comprise Fe nano particles.