Method and apparatus for joule carbonization or graphitization of fibers made from intrinsically electrically-conductive polymers

Abstract

A method for joule carbonization of fibers includes subjecting the fibers, made from an intrinsically electrically-conductive material, to a current density sufficient to heat the fibers to a carbonization temperature of between 900-2000° C. whereby the fibers are carbonized into carbon fibers. A method for joule graphitization of fibers includes subjecting the fibers, made from an intrinsically electrically-conductive material, to a current density sufficient to heat the fibers to a graphitization temperature of between 2400-3000° C. whereby the fibers are graphitized into graphitic carbon fiber.

What is claimed: 
     
         1 . A method for joule carbonization of fibers, comprising:
 subjecting the fibers, made from an intrinsically electrically-conductive material, to a current density sufficient to heat the fibers to a carbonization temperature of between 900-2000° C. whereby the fibers are carbonized into carbon fibers.   
     
     
         2 . The method of  claim 1 , further including feeding the fibers across a first electrically conductive roller and a second electrically conductive roller. 
     
     
         3 . The method of  claim 2 , further including applying a current across the first electrically conductive roller and the second electrically conductive roller. 
     
     
         4 . The method of  claim 3 , further including balancing, by a controller, (a) rotation speeds of the first electrically conductive roller and the second electrically conductive roller and (b) the current density of the applied current to allow continuous processing of the fiber. 
     
     
         5 . The method of  claim 4 , further including the applying of the current to the fiber without any previous oxidation or stabilization processing of the fiber. 
     
     
         6 . The method of  claim 1 , including selecting the fibers from a group of fibers made from intrinsically electrically conductive materials consisting of a polyacetylene, a polythiophene, a polypyrrole, a polyaniline, polyphenylene, a derivative thereof and polymer blends thereof. 
     
     
         7 . A method for joule graphitization of fibers, comprising:
 subjecting the fibers, made from an intrinsically electrically-conductive material, to a current density sufficient to heat the fibers to a graphitization temperature of between 2400-3000° C. whereby the fibers are graphitized into graphitic carbon fibers.   
     
     
         8 . The method of  claim 7 , further including feeding the fibers across a first electrically conductive roller and a second electrically conductive roller. 
     
     
         9 . The method of  claim 8 , further including applying a current across the first electrically conductive roller and the second electrically conductive roller. 
     
     
         10 . The method of  claim 9 , further including balancing, by a controller, (a) rotation speeds of the first electrically conductive roller and the second electrically conductive roller and (b) the current density of the applied current to allow continuous processing of the fiber. 
     
     
         11 . The method of  claim 10 , further including the applying of the current to the fiber without any previous oxidation or stabilization processing of the fiber. 
     
     
         12 . The method of  claim 7 , including selecting the fibers from a group of fibers made from intrinsically electrically conductive materials consisting of a polyacetylene, a polythiophene, a polypyrrole, a polyaniline, a polyphenylene, a derivative thereof and polymer blends thereof. 
     
     
         13 . An apparatus for joule carbonization or graphitization of fibers made from intrinsically conductive polymers, comprising:
 a first electrically conductive roller;   a second electrically conductive roller;   a current source having a positive terminal connected to one of the first electrically conductive roller and the second electrically conductive roller and a negative terminal connected to another of the first electrically conductive roller and the second electrically conductive roller; and   a drive motor system adapted for driving the first electrically conductive roller and the second electrically conductive roller.   
     
     
         14 . The apparatus of  claim 13 , further including a source of intrinsically electrically-conductive fiber adapted for feeding the intrinsically conductive fiber that is serially looped around the first electrically conductive roller and the second electrically conductive roller. 
     
     
         15 . The apparatus of  claim 14 , further including a support, wherein the first electrically conductive roller and the second electrically conductive roller are carried on the support and freely rotate with respect to the support. 
     
     
         16 . The apparatus of  claim 15 , wherein the fibers are made from an intrinsically electrically conductive material consisting of a polyacetylene, a polythiophene, a polypyrrole, a polyaniline, a polyphenylens, a derivative thereof and polymer blends thereof. 
     
     
         17 . The apparatus of  claim 16 , further including a controller operatively connected to the current source and the drive motor system, the controller being adapted to balance (a) rotation speeds of the first electrically conductive roller and the second electrically conductive roller and (b) a current density of a current applied across the first electrically conductive roller and the second electrically conductive roller, to allow continuous processing of the fiber. 
     
     
         18 . The apparatus of  claim 13 , further including a controller operatively connected to the current source and the drive motor system, the controller being adapted to balance (a) rotation speeds of the first electrically conductive roller and the second electrically conductive roller and (b) a current density of a current applied across the first electrically conductive roller and the second electrically conductive roller, to allow continuous processing of the fiber.