Patent ID: 7794683

Claim:
A method for preparing a functionalized carbon nanotube, comprising: converting a carboxylic acid of a carbon nanotube to acyl azide groups using diphenylphosphoryl azide prior to a Curtius Rearrangement for forming an isocyanate functionalized carbon nanotube and hydrolyzing the isocyanate functionalized carbon nanotube for forming an amino functionalized carbon nanotube; and oxidizing said amino-functionalized carbon nanotube with an oxidation reagent for forming a functionalized carbon nanotube, wherein the functionalized carbon nanotube comprises a structure of CNT—{[(W) m —L] q —Z} n , wherein m and q are independently 0 or 1; n is from 1 to 1,000; CNT is a carbon nanotube with at least two ends and at least one side wall; Z is a nitrogen based functional group; W is a bridging functional group covalently attached to a lattice carbon of the carbon nanotube CNT; and L is a divalent linker including two ends with a first end covalently attached to the nitrogen based functional group Z and a second end covalently attached to a lattice carbon of the carbon nanotube directly when m is 0 or via the bridging functional group W when m is 1, wherein m and q each are 0 so that Z is directly attached to CNT, and wherein said oxidation reagent is meta-chloroperbenzoic acid, and wherein a number of acidic sites on the functionalized CNT is approximately 9.6-11%.