Functionalized graphene sheets having high carbon to oxygen ratios

Abstract

Functionalized graphene sheets having a carbon to oxygen molar ratio of at least about 23:1, an apparatus for preparing the same, and method of preparing the same using the apparatus.

1 - 20 . (canceled) 
     
     
         21 . A apparatus for making functionalized graphene sheets, comprising:
 a tube having a first end opposing a second end;   an inlet tube traversing the first end that receives carbonaceous material and introduces the carbonaceous material within the tube;   a heat source positioned proximate to the tube to heat carbonaceous material positioned within the tube and thereby cause a reaction involving the carbonaceous material;   an outlet projecting from the first end and positioned distal to the heat source;   a filter coupled to the outlet;   a vacuum pump coupled to the outlet and positioned distal to the tube thereby causing carbonaceous material positioned within the tube to pass through the outlet to the filter for collection;   an opening positioned proximate to the second end facilitating one or more of removal of the contents of the tube to an environment external to the tube and introduction of a gas in to the tube;   wherein   carbonaceous material collected by the filter comprises functionalized graphene sheets that comprise:   a carbon to oxygen ratio for at least about 23:1;   a bulk density of about 0.1 kg/m 3  to about 40 kg/m 3 ;   fully exfoliated sheets of graphene;   a diffraction pattern displaying no signature corresponding to graphite or graphite oxide; and   the functionalized graphene sheets are dry.   
     
     
         22 . The apparatus of  claim 21 , further comprising a frit positioned within the tube. 
     
     
         23 . The apparatus of  claim 21 , further comprising a source for the carbonaceous material coupled to the inlet tube and positioned distal to the tube. 
     
     
         24 . The apparatus of  claim 21 , wherein the carbonaceous material comprise graphite oxide. 
     
     
         25 . The apparatus of  claim 21 , wherein the carbonaceous material comprise functional graphene sheets. 
     
     
         26 . The apparatus of  claim 21 , wherein the gas comprises one or more of argon, nitrogen, and hydrogen. 
     
     
         27 . The apparatus of  claim 21 , wherein the carbonaceous material received by the tube comprises a carrier gas. 
     
     
         28 . The apparatus of  claim 27 , wherein the carrier gas comprises one or more of argon, nitrogen, and hydrogen 
     
     
         29 . A method to form functionalized graphene sheets using the apparatus of  claim 21 , comprising:
 adding a carbonaceous material to the inlet;   activating the heat source to achieve a threshold temperature and thereby cause the reaction; and   activating the vacuum pump thereby causing the filter to collect a product of the reaction.   
     
     
         30 . The method of  claim 29 , wherein the carbonaceous material comprises graphite oxide or functionalized graphene sheets. 
     
     
         31 . The method of  claim 29 , further comprising adding the product to the inlet. 
     
     
         32 . The method of  claim 29 , wherein adding the carbonaceous material comprises:
 holding the carbonaceous material within the tube for a threshold period of time;   flushing the tube with a second gas via one or more of the opening and the inlet tube while activating the heat source ; and   wherein the second gas comprises one or more of argon and hydrogen.   
     
     
         33 . The method of  claim 32 , wherein the threshold period of time is 3 minutes to 120 minutes.