Methods of treating carbon nanotubes and conductive elements including such carbon nanotubes

Abstract

A method of treating an elongated conductive element comprises exposing a conductive element sequentially to at least two dopants being different in composition. The dopants may include an acidic dopant and a halogen-based dopant. The conductive element comprises a plurality of carbon nanotubes and has a linear density in a range from about 0.1 tex to about 2.0 tex. The method further comprises mechanically densifying the conductive element. The elongated conductive element comprises at least one carbon nanotube fiber doped with a plurality of p-type dopants comprising at least one acidic dopant and at least one halogen-based dopant. The at least one carbon nanotube fiber has an electrical resistivity equal to or less than about 55 μΩ·cm and an ultimate tensile strength equal to or greater than about 1 GPa.

1 . An elongated conductive element comprising:
 at least one carbon nanotube fiber doped with a plurality of p-type dopants, the plurality of p-type dopants comprising at least one acidic dopant and at least one halogen-based dopant;   wherein the at least one carbon nanotube fiber has an electrical resistivity equal to or less than about 55 μΩ·cm and an ultimate tensile strength equal to or greater than about 1 GPa.   
     
     
         2 . The elongated conductive element of  claim 1 , wherein the at least one acidic dopant comprises one of oleum, chlorosulfonic acid, or nitric acid and the at least one halogen-based dopant comprises one of bromine, chlorine, iron trichloride, or a bromine chloride. 
     
     
         3 . The elongated conductive element of  claim 1 , wherein the at least one carbon nanotube fiber has a linear density of between about 1 tex and about 10 tex. 
     
     
         4 . The elongated conductive element of  claim 1 , wherein the at least one carbon nanotube fiber has a linear density of between about 1 tex and about 20 tex. 
     
     
         5 . The elongated conductive element of  claim 1 , wherein the elongated conductive element has a linear density of between about 50 tex and about 200 tex. 
     
     
         6 . The elongated conductive element of  claim 5 , wherein the elongated conductive element has a linear density of between about 96 tex and about 130 tex. 
     
     
         7 . The elongated conductive element of  claim 1 , wherein the at least one carbon nanotube fiber comprises single-walled carbon nanotubes. 
     
     
         8 . The elongated conductive element of  claim 1 , wherein the at least one carbon nanotube fiber comprises double-walled carbon nanotubes. 
     
     
         9 . The elongated conductive element of  claim 1 , wherein the at least one carbon nanotube fiber comprises multi-walled carbon nanotubes. 
     
     
         10 . The elongated conductive element of  claim 1 , wherein the at least one carbon nanotube fiber comprises at least one chemically densified carbon nanotube fiber. 
     
     
         11 . The elongated conductive element of  claim 1 , wherein the at least one carbon nanotube fiber comprises at least one mechanically densified carbon nanotube fiber. 
     
     
         12 . The elongated conductive element of  claim 1 , wherein the at least one carbon nanotube fiber comprises at least one twisted carbon nanotube fiber. 
     
     
         13 . The elongated conductive element of  claim 1 , wherein the at least one carbon nanotube fiber comprises at least one strained carbon nanotube fiber. 
     
     
         14 . The elongated conductive element of  claim 1 , wherein the at least one carbon nanotube fiber comprises a plurality of nanotube fibers combined to form a carbon nanotube assembly. 
     
     
         15 . The elongated conductive element of  claim 14 , wherein the carbon nanotube assembly comprises at least one of a yarn, a tape, a ribbon, a film, a cable, a wire, a rope, and a thread. 
     
     
         16 . The elongated conductive element of  claim 1 , wherein the at least one carbon nanotube fiber comprises a plurality of nanotube fibers braided to form a carbon nanotube assembly. 
     
     
         17 . The elongated conductive element of  claim 1 , wherein the at least one carbon nanotube fiber comprises a plurality of nanotube fibers woven to form a carbon nanotube assembly. 
     
     
         18 . The elongated conductive element of  claim 1 , wherein the at least one carbon nanotube fiber comprises a plurality of nanotube fibers twisted to form a carbon nanotube assembly.