Process for derivatizing carbon nanotubes with diazonium species and compositions thereof

Abstract

The invention incorporates new processes for the chemical modification of carbon nanotubes. Such processes involve the derivatization of multi- and single-wall carbon nanotubes, including small diameter (ca. 0.7 nm) single-wall carbon nanotubes, with diazonium species. The method allows the chemical attachment of a variety of organic compounds to the side and ends of carbon nanotubes. These chemically modified nanotubes have applications in polymer composite materials, molecular electronic applications, and sensor devices. The methods of derivatization include electrochemical induced reactions, thermally induced reactions (via in-situ generation of diazonium compounds or preformed diazonium compounds), and photochemically induced reactions. The derivatization causes significant changes in the spectroscopic properties of the nanotubes. The estimated degree of functionality is ca. 1 out of every 20 to 30 carbons in a nanotube bearing a functionality moiety. Such electrochemical reduction processes can be adapted to apply site-selective chemical functionalization of nanotubes. Moreover, when modified with suitable chemical groups, the derivatized nanotubes are chemically compatible with a polymer matrix, allowing transfer of the properties of the nanotubes (such as, mechanical strength or electrical conductivity) to the properties of the composite material as a whole. Furthermore, when modified with suitable chemical groups, the groups can be polymerized to form a polymer that includes carbon nanotubes.

1 . A method for derivatizing sidewalls of carbon nanotubes comprising: 
 (a) selecting a plurality of carbon nanotubes; and    (b) reacting the plurality of carbon nanotubes with a diazonium specie; 
 wherein the plurality of carbon nanotubes are electrochemically reacted with the diazonium specie.  
   
     
     
         2 . A method for derivatizing single-wail carbon nanotubes comprising: 
 (a) selecting an assembly of single-wall carbon nanotubes;    (b) immersing the assembly in a solution comprising a diazonium specie; and    (c) applying a potential to the assembly to electrochemically react the assembly with the diazonium specie.    
     
     
         3 . A method for derivatizing sidewalls of carbon nanotubes comprising: 
 (a) selecting a plurality of carbon nanotubes; and    (b) reacting the plurality of carbon nanotubes with a diazonium specie;    (c) immersing the assembly in a solution comprising the diazonium specie; and    (d) applying a potential to the assembly.    
     
     
         4 . The method of any one of claims  2  or  3 , wherein the potential is a negative potential.  
     
     
         5 . The method of any one of claims  2  or  3 , wherein the solution further comprises a supporting electrolyte specie.  
     
     
         6 . The method of any one of claims  2  or  3 , wherein the step of applying a potential to the assembly comprises holding the assembly with an alligator clip treated with a colloidal silver paste.  
     
     
         7 . A method for derivatizing carbon nanotubes comprising: 
 (a) preparing an assembly, wherein 
 (i) the assembly comprises a first plurality of carbon nanotubes and a second plurality of carbon nanotubes; and  
 (ii) wherein the carbon nanotubes in the first plurality and the carbon nanotubes in the second plurality can be individually addressed electronically;  
   (b) immersing the assembly in a diazonium specie; and    (c) applying a negative potential to the assembly to cause the first plurality to essentially come in contact with the second plurality; and    (d) electrochemically reacting the assembly with the diazonium specie.    
     
     
         8 . A method for derivatizing carbon nanotubes comprising: 
 (a) preparing an assembly of carbon nanotubes    (b) immersing the assembly in a first diazonium specie;    (c) applying a potential to the assembly in a first direction;    (d) electrochemically reacting the assembly with the first diazonium specie;    (e) immersing the assembly in a second diazonium specie;    (f) applying a potential to the assembly in a second direction; and    (g) electrochemically reacting the assembly with the second diazonium specie.    
     
     
         9 . The method of any one of claims  7  or  8 , wherein the carbon nanotubes of the first plurality comprise single-wall carbon nanotubes and the carbon nanotubes of the second plurality comprise single-wall carbon nanotubes.  
     
     
         10 . The method of  claim 9 , wherein the assembly is a crossbar architecture of carbon nanotubes.  
     
     
         11 . The method of  claim 10 , wherein the preparation of the assembly comprises fluid flow over a patterned surface.  
     
     
         12 . The method of  claim 10 , wherein the preparation of the assembly comprises direct carbon nanotube growth between posts.  
     
     
         13 . The method of  claim 9 , wherein the preparation of the assembly comprises fluid flow over a patterned surface.  
     
     
         14 . The method of  claim 9 , wherein the preparation of the assembly comprises direct carbon nanotube growth between posts.  
     
     
         15 . The method of any one of claims  7  or  8 , wherein the assembly is a crossbar architecture of carbon nanotubes.  
     
     
         16 . The method of any one of claims  7  or  8 , wherein the preparation of the assembly comprises fluid flow over a patterned surface.  
     
     
         17 . The method of any one of claims  7  or  8 , wherein the preparation of the assembly comprises direct carbon nanotube growth between posts.  
     
     
         18 . The method of any one of claims  1 ,  2 ,  3 ,  7 , or  8 , wherein the carbon nanotubes are single-wall carbon nanotubes.  
     
     
         19 . The method of any one of claims  1 ,  2 ,  3 ,  7 , or  8 , wherein the carbon nanotubes are multi-wall carbon nanotubes.