Cnt-infused fiber and method therefor

Abstract

A carbon nanotube-infused fiber and a method for its production are disclosed. Nanotubes are synthesized directly on a parent fiber by first applying a catalyst to the fiber. The properties of the carbon nanotube-infused fiber will be a combination of those of the parent fiber as well as those of the infused carbon nanotubes.

What is claimed is the following: 
     
         1 . A method of infusing carbon nanotubes on a parent fiber, the method comprising:
 applying a carbon nanotube-forming catalyst on a surface of a parent fiber comprising a plurality of filaments, thereby forming a catalyst-laden fiber;   pre-heating the catalyst-laden fiber to a temperature between about 500° C. and about 1000° C. prior to synthesizing carbon nanotubes on the catalyst-laden fiber; and   while maintaining the catalyst-laden fiber at a temperature ranging between about 500° C. and about 1000° C., synthesizing carbon nanotubes on the catalyst-laden fiber while the catalyst-laden fiber is being transported, thereby forming a carbon nanotube-infused fiber.   
     
     
         2 . The method of  claim 1 , further comprising:
 removing a sizing material from the parent fiber prior to applying a carbon nanotube-forming catalyst thereto.   
     
     
         3 . The method of  claim 1 , further comprising:
 applying a resin to the carbon nanotube-infused fiber.   
     
     
         4 . The method of  claim 3 , further comprising:
 winding the carbon nanotube-infused fiber about a mandrel after applying the resin.   
     
     
         5 . The method of  claim 1 , further comprising:
 spreading the filaments of the parent fiber.   
     
     
         6 . The method of  claim 5 , re-bundling the filaments of the spread parent fiber. 
     
     
         7 . The method of  claim 1 , wherein the carbon nanotube-forming catalyst comprises a transition metal. 
     
     
         8 . The method of  claim 1 , wherein the carbon nanotubes are synthesized in a carbon plasma at atmospheric pressure. 
     
     
         9 . The method of  claim 1 , wherein the parent fiber comprises a fiber tow. 
     
     
         10 . A system for producing carbon nanotube-infused fibers, the system comprising:
 a carbon nanotube infusion station comprising, in series, a catalyst application station, a heater, and a plasma spray station; and   a transport mechanism operable for conveying a fiber comprising a plurality of filaments through the carbon nanotube infusion station.   
     
     
         11 . The system of  claim 10 , further comprising:
 a station for spreading the fiber before the carbon nanotube infusion station.   
     
     
         12 . The system of  claim 11 , further comprising:
 a station for re-bundling the spread fiber after the carbon nanotube infusion station.   
     
     
         13 . The system of  claim 10 , further comprising:
 a station for removing a sizing material from the fiber before the carbon nanotube infusion station.   
     
     
         14 . The system of  claim 13 , wherein the station for removing a sizing material comprises a heater. 
     
     
         15 . The system of  claim 10 , wherein the plasma spray station comprises a plurality of carbon plasma sprayers. 
     
     
         16 . The system of  claim 15 , wherein the plasma spray station further comprises heaters at the carbon plasma sprayers. 
     
     
         17 . The system of  claim 10 , further comprising:
 a resin bath after the carbon nanotube infusion station.   
     
     
         18 . A composition comprising a carbon nanotube-infused fiber, wherein the carbon nanotube-infused fiber comprises:
 a parent fiber comprising a plurality of filaments; and   a plurality of carbon nanotubes covalently bonded to the parent fiber.   
     
     
         19 . The composition of  claim 18 , further comprising a resin. 
     
     
         20 . The composition of  claim 18 , wherein the parent fiber comprises a fiber tow. 
     
     
         21 . The composition of  claim 18 , wherein the carbon nanotube-infused fiber is prepared by a process comprising:
 applying a carbon nanotube-forming catalyst on a surface of a parent fiber comprising a plurality of filaments, thereby forming a catalyst-laden fiber;   pre-heating the catalyst-laden fiber to a temperature between about 500° C. and about 1000° C. prior to synthesizing carbon nanotubes on the catalyst-laden fiber; and   while maintaining the catalyst-laden fiber at a temperature ranging between about 500° C. and about 1000° C., synthesizing carbon nanotubes on the catalyst-laden fiber while the catalyst-laden fiber is being transported.   
     
     
         22 . The composition of  claim 18 , wherein the parent fiber comprises a carbon fiber lacking a sizing material. 
     
     
         23 . The composition of  claim 18 , wherein the electrical resistivity of the carbon nanotube-infused fiber is lower than the electrical resistivity of the parent fiber.