Continuous vapor grown carbon fiber mat and the producing method thereof

Abstract

A method for fabricating a continuous vapor grown carbon fiber mat including: (a) providing a substrate which has a catalyst on its surface; (b) placing the substrate in a furnace; (c) introducing hydrogen, ammonia, or combinations thereof into the furnace; (d) adjusting a temperature of the furnace to 400° C. to 900° C. to proceed heat treatment for 15 to 90 minutes; (e) adding a carbon-containing compound into the furnace and adjusting the ratio of the carbon-containing compound and the hydrogen, ammonia, or combinations thereof; (f) adjusting the temperature of the furnace to 600° C. to 1200° C. to crack the carbon-containing compound, and thereby forming a carbon fiber mat, where time for reaction is 1 to 3 hours. A continuous vapor grown carbon fiber mat and a graphitized carbon fiber mat are also provided.

What is claimed: 
     
         1 . A carbon fiber mat, which is fabricated by the following steps:
 (a) providing a substrate with a catalyst on its surface;   (b)placing said substrate in a furnace;   (c) introducing hydrogen, ammonia, or a combination thereof into said furnace;   (d) adjusting the temperature of said furnace to 400° C. to 900° C. to proceed a heat treatment for 15 to 90 minutes, thereby obtaining nucleation points on said substrate, in which the density of said nucleation points distributes between 1˜50 sites/μm 2 , and the size of said nucleation points distributes between 10˜2000 nm;   (e) adding a carbon-containing compound into said furnace and adjusting the ratio of said carbon-containing compound and said hydrogen, ammonia, or a combination thereof; and   (f) adjusting the temperature of said furnace to 600° C. to 1200° C. to crack said carbon-containing compound and reacting for 1 to 3 hours, and thereby forming a carbon fiber mat.   
     
     
         2 . A graphitized carbon fiber mat, which is obtained by heating the carbon fiber mat according to  claim 1  in inert gases at 2400° C. to 2800° C.; wherein said carbon fiber mat has a graphitization degree of 99˜100%. 
     
     
         3 . The graphitized carbon fiber mat according to  claim 2 , which has a room temperature thermal conductivity of up to 1950 W/m-k. 
     
     
         4 . A polymer matrix composite material, characterized by comprising the graphitized carbon fiber mat according to  claim 2 , which has a thermal conductivity of 400 W/m-K to 600 W/m-K.