Calcination of carbon nanotube compositions

Abstract

A carbon nanotube composition and method of making the same. The composition is made by: heating a precursor composition under a non-oxidizing or reducing atmosphere to form a carbon composition of carbon nanotubes and amorphous carbon; and calcining the carbon composition in the presence of oxygen to oxidize and vaporize the amorphous carbon without oxidizing the carbon nanotubes. The precursor composition includes a mixture or complex of a transition metal compound and an organic compound that chars at elevated temperatures.

1 . A carbon nanotube composition made by:
 heating a precursor composition under a non-oxidizing or reducing atmosphere and under thermal conditions effective to form a carbon composition comprising carbon nanotubes and amorphous carbon;
 wherein the precursor composition comprises a mixture or complex of:
 a transition metal compound; and 
 an organic compound that chars at elevated temperatures; and 
 
   calcining the carbon composition in the presence of oxygen under thermal conditions that oxidize and vaporize the amorphous carbon without oxidizing the carbon nanotubes.   
     
     
         2 . The carbon nanotube composition of  claim 1 , wherein heating the precursor composition comprises heating the precursor composition under nitrogen to a temperature of at least about 500° C. 
     
     
         3 . The carbon nanotube composition of  claim 1 , wherein calcining the carbon composition comprises heating the carbon composition under oxygen to a temperature of from about 400° C. to about 500° C. 
     
     
         4 . The carbon nanotube composition of  claim 1 , wherein the transition metal compound is an organometallic compound, a transition metal salt, octacarbonyl dicobalt, nonacarbonyl diron, biscyclooctadiene nickel, ferrocenylethynyl phenylethynylbenzene, or a combination thereof. 
     
     
         5 . The carbon nanotube composition of  claim 1 , wherein the organic compound comprises an aromatic group, an ethynyl group, aromatic precursor, or a combination thereof. 
     
     
         6 . The carbon nanotube composition of  claim 1 , wherein the organic compound is an aromatic-containing polymer, polyacrylonitrile, a phthalonitrile-terminated polymer, a phthalonitrile-terminated bisphenol A-benzophenone polymer, a cyanate ester-terminated aromatic polymer, a cyanate ester-terminated bisphenol A-benzene polymer, an aromatic epoxy, a polyether sulfone, a polyetheretherketone, a phenolic polymer, an aromatic polyimide, a polyphenylene sulfide, a polycarbonate, coal pitch, petroleum pitch, 1,2,4,5-tetrakis(phenylethynyl)benzene, or a combination thereof. 
     
     
         7 . The carbon nanotube composition of  claim 1 , wherein the precursor composition comprises a metal-ethynyl complex-containing compound. 
     
     
         8 . The carbon nanotube composition of  claim 1 , wherein the precursor composition comprises a transition metal salt and an aromatic compound or a polymer. 
     
     
         9 . The carbon nanotube composition of  claim 1 , wherein carbon nanotube composition is a porous, solid material; a film; a fiber; or a shaped solid component. 
     
     
         10 . A reduced carbon nanotube composition made by:
 heating the carbon nanotube composition of  claim 1  under a non-oxidizing or reducing atmosphere and under thermal conditions effective to reduce a metal oxide in the carbon nanotube composition to metal.   
     
     
         11 . The reduced carbon nanotube composition of  claim 10 , wherein heating the carbon nanotube composition comprises heating the carbon nanotube composition under hydrogen to a temperature of from about 500 to about 800° C. 
     
     
         12 . The reduced carbon nanotube composition of  claim 10 , wherein heating the carbon nanotube composition comprises heating the carbon nanotube composition under a vacuum. 
     
     
         13 . A method comprising:
 heating a precursor composition under a non-oxidizing or reducing atmosphere and under thermal conditions effective to form a carbon composition comprising carbon nanotubes and amorphous carbon;
 wherein the precursor composition comprises a mixture or complex of:
 a transition metal compound; and 
 an organic compound that chars at elevated temperatures; and 
 
   calcining the carbon composition in the presence of oxygen under thermal conditions that oxidize and vaporize the amorphous carbon without oxidizing the carbon nanotubes.   
     
     
         14 . The method of  claim 13 , wherein heating the precursor composition comprises heating the precursor composition under nitrogen to a temperature of at least about 500° C. 
     
     
         15 . The method of  claim 13 , wherein calcining the carbon composition comprises heating the carbon composition under oxygen to a temperature of from about 400° C. to about 500° C. 
     
     
         16 . The method of  claim 13 , wherein the transition metal compound is an organometallic compound, a transition metal salt, octacarbonyl dicobalt, nonacarbonyl diron, biscyclooctadiene nickel, ferrocenylethynyl phenylethynylbenzene, or a combination thereof. 
     
     
         17 . The method of  claim 13 , wherein the organic compound comprises an aromatic group, an ethynyl group, aromatic precursor, or a combination thereof. 
     
     
         18 . The method of  claim 13 , wherein the organic compound is an aromatic-containing polymer, polyacrylonitrile, a phthalonitrile-terminated polymer, a phthalonitrile-terminated bisphenol A-benzophenone polymer, a cyanate ester-terminated aromatic polymer, a cyanate ester-terminated bisphenol A-benzene polymer, an aromatic epoxy, a polyether sulfone, a polyetheretherketone, a phenolic polymer, an aromatic polyimide, a polyphenylene sulfide, a polycarbonate, coal pitch, petroleum pitch, 1,2,4,5-tetrakis(phenylethynyl)benzene, or a combination thereof. 
     
     
         19 . The method of  claim 13 , wherein the precursor composition comprises a metal-ethynyl complex-containing compound. 
     
     
         20 . The method of  claim 13 , wherein the precursor composition comprises a transition metal salt and an aromatic compound or a polymer. 
     
     
         21 . The method of  claim 13 , wherein carbon nanotube composition is a porous, solid material; a film; a fiber; or a shaped solid component. 
     
     
         22 . The method of  claim 13 , further comprising
 heating the product of calcining the carbon composition under a non-oxidizing or reducing atmosphere and under thermal conditions effective to reduce a metal oxide in the product of calcining the carbon composition to metal.   
     
     
         23 . The method of  claim 22 , wherein heating the product of calcining the carbon composition comprises heating the product of calcining the carbon composition under hydrogen to a temperature of from about 500 to about 800° C. 
     
     
         24 . The method of  claim 22 , wherein heating the carbon nanotube composition comprises heating the carbon nanotube composition under a vacuum.