Templated Growth of Carbon Nanotubes

Abstract

A method of growing carbon nanotubes uses a synthesized mesoporous silica template with approximately cylindrical pores being formed therein. The surfaces of the pores are coated with a carbon nanotube precursor, and the template with the surfaces of the pores so-coated is then heated until the carbon nanotube precursor in each pore is converted to a carbon nanotube.

1 . A method of growing carbon nanotubes, comprising the steps of:
 synthesizing a template made from a mesoporous silica such that said template has a plurality of approximately cylindrical pores formed therein;   coating surfaces of each of said approximately cylindrical pores with a carbon nanotube precursor capable of being carbonized upon the heating thereof; and   heating said template with said surfaces of said approximately cylindrical pores so-coated until said carbon nanotube precursor in each of said approximately cylindrical pores is converted to a carbon nanotube.   
     
     
         2 . A method according to  claim 1  wherein said step of synthesizing includes the step of impregnating said mesoporous silica with a material selected from the group consisting of cobalt, iron, nickel and any other active metal. 
     
     
         3 . A method according to  claim 1  wherein said step of coating includes the step of impregnating said template with a solution of a hydrocarbon diluted in a liquid. 
     
     
         4 . A method according to  claim 3  wherein said liquid is selected to reduce hydroxyl content of said hydrocarbon. 
     
     
         5 . A method according to  claim 1  further comprising, during said step of heating, the step selected from the group consisting of applying a vacuum to said template and applying an inert atmosphere to said template. 
     
     
         6 . A method according to  claim 1  further comprising the step of dissolving said template after said step of heating. 
     
     
         7 . A method according to  claim 1  wherein said carbon nanotube precursor is a hydrocarbon. 
     
     
         8 . A semiconducting material comprising:
 a synthesized template of a mesoporous silica having a plurality of approximately cylindrical pores formed therein; and   a carbon nanotube formed in each of said approximately cylindrical pores, said carbon nanotube being grown through carbonization of a carbon nanotube precursor coated on surfaces of each of said approximately cylindrical pores, each said carbon nanotube further having no contaminants and having a diameter approximately equal to the diameter of said corresponding cylindrical pore.   
     
     
         9 . A semiconducting material as in  claim 8  further comprising a material selected from the group consisting of cobalt, iron, nickel and any other active metal impregnated in said mesoporous silica. 
     
     
         10 . A semiconducting material as in  claim 8  wherein said carbon nanotube precursor sugar-based. 
     
     
         11 . A semiconducting material as in  claim 8  wherein said synthesized template is of uniform thickness with said approximately cylindrical pores extending through said thickness and being substantially uniform in length. 
     
     
         12 . A semiconducting material as in  claim 8  wherein said carbon nanotube precursor comprises a hydrocarbon. 
     
     
         13 . A semiconducting material comprising:
 a synthesized template of a mesoporous silica having a plurality of straight approximately cylindrical pores formed therethrough and being parallel to one another with each of said straight approximately cylindrical pores having an inside diameter in the range of approximately 3.5-4.0 nanometers; and   a carbon nanotube formed in each of said straight approximately cylindrical pores, said carbon nanotube being grown through carbonization of a reduced hydroxyl group derivative of sugar coated on surfaces of each of said straight approximately cylindrical pores, each said carbon nanotube further having no contaminants and having a diameter approximately equal to the diameter of said corresponding cylindrical pore.   
     
     
         14 . A semiconducting material as in  claim 13  further comprising further comprising a material selected from the group consisting of cobalt, iron, nickel and any other active metal impregnated in said mesoporous silica. 
     
     
         15 . A semiconducting material as in  claim 13  wherein said synthesized template is of uniform thickness with said straight approximately cylindrical pores extending through said thickness. 
     
     
         16 . A semiconducting material comprising:
 a synthesized template of a mesoporous silica having a plurality of approximately cylindrical pores formed therein and separated from one another; and   a carbon nanotube formed in each of said approximately cylindrical pores, said carbon nanotube being grown through carbonization of a reduced hydroxyl group derivative of sucrose coated on surfaces of each of said approximately cylindrical pores, each said carbon nanotube further having no contaminants and having a diameter approximately equal to the diameter of said corresponding cylindrical pore.   
     
     
         17 . A semiconducting material as in  claim 16  wherein each of said approximately cylindrical pores is straight. 
     
     
         18 . A semiconducting material as in  claim 16  wherein each of said approximately cylindrical pores has a substantially uniform inside diameter along the length thereof. 
     
     
         19 . A semiconducting material as in  claim 16  wherein said synthesized template is of uniform thickness with said approximately cylindrical pores extending all the way through said thickness such that said approximately cylindrical pores are substantially uniform in length. 
     
     
         20 . A semiconducting material as in  claim 16  further comprising a material selected from the group consisting of cobalt, iron, nickel and any other active metal impregnated in said mesoporous silica. 
     
     
         21 . The method according to  claim 5  wherein the inert atmosphere is selected from the group consisting of nitrogen, helium and argon.