Activated carbon fibers and related methods for the use and production thereof and of making protective clothing and a filter module

Abstract

Activated porous carbon fibers, whose active centers are formed by pores that are filled at least in part by carbon and/or metal and/or metal carbide, obtainable by carbonization of organic or inorganic polymers, the use thereof for the adsorption or separation of gaseous substances, in particular of CO 2 , and also a method for the production thereof. The method includes the following steps. The first step is production of a spinning mixture containing polyacrylonitrile-based polymer A and an organic or metallo-organic polymer B. The next step is spinning of the spinning mixture to form mixed fibers of polymer A and polymer B. The next step is stabilization of the mixed fiber by oxidation. The next step is carbonization or graphitization of the mixed fiber under non-oxidizing conditions in such a way that the polymer B forms a carbon and/or metal and/or metal carbide residue of at least 25 wt %, this residue forming active centers.

We claim:  
     
         1 . Activated carbon fibers, comprising: 
 porous carbon fibers having a surface, an inside, and pores on said surface and said inside; and    a solid non-volatile residue from a carbonized organic polymer partly filling said pores.    
     
     
         2 . The activated carbon fibers according to  claim 1 , wherein said solid non-volatile residue includes a metal-containing residue from a carbonized metallo-organic polymer metal, said metal-containing residue being selected from the group consisting of a metal and a metal carbide.  
     
     
         3 . The activated carbon fibers according to  claim 2 , wherein: 
 said porous carbon fibers and said solid non-volatile residue form a fibrous mass; and    a metal content of said metal-containing residue is above 2 wt % of said fibrous mass.    
     
     
         4 . The activated carbon fibers according to  claim 2 , wherein said metal and metal carbide are selected from the group consisting of B, Si, Ti, Cr, W, Fe, Co, Ni, Pd, Pt, and carbides thereof.  
     
     
         5 . The activated carbon fibers according to  claim 1 , wherein said pores are filled to at least 30% by volume with said solid non-volatile residue.  
     
     
         6 . The activated carbon fibers according to  claim 1 , wherein said carbonized organic polymer is microporous.  
     
     
         7 . The activated carbon fibers according to  claim 1 , wherein at least said pores on said surface have an average diameter greater than 30 nm.  
     
     
         8 . A method of using activated porous carbon fibers, which comprises: 
 providing the activated carbon fibers according to  claim 1;  and    passing a gas mixture including CO 2  through the activated carbon fibers to separate the CO 2  from the gas mixture.    
     
     
         9 . A method of making a filter module, which comprises using the activated carbon fibers according to  claim 1  as a component in the filter module.  
     
     
         10 . A method of making protective clothing, which comprises using the activated carbon fibers according to  claim 1  as a component in the protective clothing.  
     
     
         11 . A method for producing activated carbon fibers, which comprises the following steps: 
 a) producing a spinning mixture containing a polyacrylonitrile-based polymer A and a carbonizable organic polymer B, the polymer B having an original mass and being carbonizable under non-oxidizing conditions to leave behind a solid non-volatile residue of at least 25% of the original mass;    b) spinning the spinning mixture to form mixed fibers of polymer A and polymer B;    c) stabilizing the mixed fibers by oxidation; and    d) one of carbonizing and graphitizing the mixed fibers under non-oxidizing conditions to form a solid non-volatile residue of at least 25% of the original mass from the polymer B.    
     
     
         12 . The method according to  claim 11 , wherein the polymer B includes an organic polymer selected from the group consisting of a polyamide, a copolyaramide, a para-aramide, a polyaramide, a phenolic resin, a polyester, and a cellulose.  
     
     
         13 . The method according to  claim 11 , which further comprises: 
 including a metallo-organic constituent carbonizable under non-oxidizing conditions to yield a solid non-volatile residue in the polymer B; and    selecting the solid non-volatile residue from a group of metal containing residues consisting of a metal and a metal carbide.    
     
     
         14 . The method according to  claim 13 , which further comprises: 
 including metallo-organic polymers with a metal constituent in the polymer B; and    selecting the metal constituent from the group consisting of Al, B, Si, Ti, Cr, Fe, Co, Ni, W, Pd, and Pt.    
     
     
         15 . The method according to  claim 13 , which further comprises: 
 including a metallic polymer selected in the polymer B; and    selecting the metallic polymer from the group consisting of a cyclopentadienyl and a metallic polyacetate.    
     
     
         16 . The method according to  claim 11 , which further comprises heating to temperatures above 500° C. during step d).  
     
     
         17 . The method according to  claim 11 , which further comprises maintaining a temperature from 230 to 300° C. during step c).  
     
     
         18 . The method according to  claim 11 , wherein step b) includes dry spinning to form the mixed fiber.  
     
     
         19 . The method according  claim 11 , wherein the polymer B in the mixed fiber is a precipitate having an average size below 1500 nm.  
     
     
         20 . The method according to  claim 11 , wherein polymer B is a thermoplastic first stabilized by step c).  
     
     
         21 . The method according to  claim 11 , wherein polymer B is a thermoplastic first rendered infusible by step c).  
     
     
         22 . The method according to  claim 11 , wherein: 
 the mixed fiber has a mass; and    the polymer B amounts to 2 to 50% of the mass of the mixed fiber.