Fabrication method for porous carbon fibers

Abstract

Disclosed is a method for fabrication of porous carbon fibers. More particularly, the method for fabrication of porous carbon fibers comprises the steps of: processing starch to prepare a gelled starch solution; adding organic acid to the gelled starch solution to prepare a starch solution; dissolving carbon nanotubes in a solvent and adding fiber formable polymer thereto to prepare a carbon nanotube/fiber formable polymer solution; mixing the starch solution with the carbon nanotube/fiber formable polymer solution obtained from the above steps, in order to prepare a carbon nanotube/starch/fiber formable polymer solution; electro-spinning or wet-state spinning the prepared carbon nanotube/starch/fiber formable polymer solution to produce starch composite fibers; oxidation heating the starch composite fibers, then, executing carbonization and vacuum heat treatment of the heated fibers, so as to fabricate the porous carbon fibers. The fabricated porous carbon fiber has high specific surface area and high capacitance, thereby being favorably applicable in manufacturing electrodes for a super capacitor, fuel cell, etc.

1 . A method for fabricating a porous carbon fibers comprising:
 (a) processing starch to prepare a gelled starch solution;   (b) adding organic acid to the gelled starch solution to prepare a starch solution;   (c) dissolving carbon nanotubes in a solvent and adding fiber formable polymer thereto to prepare a carbon nanotube/fiber formable polymer solution;   (d) mixing the starch solution of step (b) with the carbon nanotube/fiber formable polymer solution of step (c) to prepare a carbon nanotube/starch/fiber formable polymer solution;   (e) electro-spinning or wet-state spinning the prepared carbon nanotube/starch/fiber formable polymer solution to produce starch composite fibers;   (f) oxidation heating the starch composite fibers, then, executing carbonization and vacuum heat treatment of the heated fibers, so as to fabricate the porous carbon fibers.   
     
     
         2 . The method according to  claim 1 , wherein the processing in step (a) includes heating starch at 100 to 150° C. and then cooling the same to room temperature. 
     
     
         3 . The method according to  claim 1 , wherein the organic acid in step (b) is at least one selected from a group consisting of p-toluene sulfonic acid, methane sulfonic acid, trifluoromethane sulfonic acid, alkylbenzene sulfonic acid and p-aminobenzene sulfonic acid. 
     
     
         4 . The method according to  claim 1 , wherein the solvent in step (c) is at least one selected from a group consisting of water, ethanol, methanol, dichloromethanol, isopropanol, acetone and hexafluoroisopropanol (HFIP). 
     
     
         5 . The method according to  claim 1 , wherein the fiber formable polymer in step (c) is at least one selected from a group consisting of polyvinyl alcohol, polyethylene oxide, polycarboate, polylactic acid, polyvinylcarbazole, polymethacrylate, cellulose acetate, collagen, polycaprolactone and poly(2-hydroxyethyl methacrylate). 
     
     
         6 . The method according to  claim 1 , wherein the fiber formable polymer is added to the starch, in a ratio of percent (%) by weight of 5:5 to 8:2 for starch: fiber formable polymer. 
     
     
         7 . The method according to  claim 1 , wherein the oxidation heating in step (f) is executed at 150 to 300° C. 
     
     
         8 . The method according to  claim 1 , wherein the carbonization in step (f) is executed at 500 to 1,400° C. under vacuum or an inert gas atmosphere. 
     
     
         9 . The method according to  claim 1 , wherein the vacuum heat treatment in step (f) is executed at 1,400 to 2,200° C. 
     
     
         10 . The method according to  claim 1 , wherein the porous carbon fiber has a great amount of mesopores with an average diameter ranging from 5 to 10 nm. 
     
     
         11 . A porous carbon fiber fabricated by the method as set forth in  claim 1 . 
     
     
         12 . A felt including the porous carbon fiber as set forth in  claim 11 . 
     
     
         13 . Use of the porous carbon fiber as set forth in  claim 11  in manufacturing an electrode for a super capacitor having high capacitance. 
     
     
         14 . Use of the porous carbon fiber as set forth in  claim 11  in manufacturing an electrode for a fuel cell.