Methods of exfoliating and dispersing a graphitic material into polymer matrices using supercritical fluids

Abstract

Embodiments described herein relate generally to systems and methods for manufacturing a master batch with a graphitic material dispersed in a polymer matrix. In some embodiments, a method for manufacturing the master batch can include combining the graphitic material with a polymer, adding a supercritical fluid to the mixture, and depressurizing the supercritical fluid to remove the supercritical fluid. In some embodiments, the method includes mixing the graphitic material and the polymer for a first time period to form a first mixture and transferring the supercritical fluid to the first mixture to form a second mixture. In some embodiments, the method includes mixing the second mixture for a second time period and depressurizing the second mixture to allow the supercritical fluid to transition to a gas phase.

1 .- 23 . (canceled) 
     
     
         24 . A composition, comprising:
 a polymer; and   a plurality of graphene flakes dispersed in the polymer, the plurality of graphene flakes having a thickness of about 1 to about 10 graphene layers and an average lateral dimension of about 500 nm to about 5 μm, the plurality of graphene flakes including charged edges that facilitate hydroxylation and/or carboxylation of the charged edges.   
     
     
         25 . The composition of  claim 24 , wherein the polymer includes at least one of polyethylene, polypropylene, a polyolefin, acrylonitrile butadiene styrene, a poly(meth)acrylate, polystyrene, a polyamide, a polyester, polycarbonate, polyurethane, a polyimide, a polysulfone, a poly(aryl ether ketone), a fluorinated polymer, a thermoplastic elastomer (TPE), thermoplastic polyurethane (TPU), ethylene butyl acrylate (EBA), ethylene-vinyl acetate (EVA), polylactic acid (PLA), polyetherketone (PEK), polyether ether ketone (PEEK), acrylonitrile styrene acrylate (ASA), polyoxymethylene (POM), polyphenylene sulfide (PPS), polyphenylsulfone (PPSU), thermoset polyurethane, thermoset polyester, epoxy, or silicone rubber. 
     
     
         26 . The composition of  claim 24 , wherein the weight ratio of the polymer to the graphene flakes is between about 1 and about 100. 
     
     
         27 . The composition of  claim 24 , further comprising:
 a supercritical fluid disposed in the polymer.   
     
     
         28 . The composition of  claim 27 , wherein the supercritical fluid includes at least one of carbon dioxide, nitrogen, xenon, ethane, hydrogen, water, methylene chloride, hexane, methane, ethylene, propylene, methanol, ethanol, acetone, or nitrous oxide. 
     
     
         29 . The composition of  claim 24 , wherein the graphene flakes have little or no crystalline imperfection, such that the graphene flakes have a G-band intensity to D-band intensity ratio between about 14 and about 28. 
     
     
         30 . A pellet, comprising the composition of  claim 24 . 
     
     
         31 . An article, comprising the composition of  claim 24 . 
     
     
         32 . A composition, comprising:
 a polymer;   a plurality of graphene flakes dispersed in the polymer, the plurality of graphene flakes having a thickness of about 1 to about 10 graphene layers and an average lateral dimension of about 500 nm to about 5 μm; and   a supercritical fluid disposed in the polymer.   
     
     
         33 . The composition of  claim 32 , wherein the plurality of graphene flakes have an aspect ratio between about 50 and about 2,000. 
     
     
         34 . The composition of  claim 32 , wherein the polymer includes at least one of polyethylene, polypropylene, a polyolefin, acrylonitrile butadiene styrene, a poly(meth)acrylate, polystyrene, a polyamide, a polyester, polycarbonate, polyurethane, a polyimide, a polysulfone, a poly(aryl ether ketone), a fluorinated polymer, a thermoplastic elastomer (TPE), thermoplastic polyurethane (TPU), ethylene butyl acrylate (EBA), ethylene-vinyl acetate (EVA), polylactic acid (PLA), polyetherketone (PEK), polyether ether ketone (PEEK), acrylonitrile styrene acrylate (ASA), polyoxymethylene (POM), polyphenylene sulfide (PPS), polyphenylsulfone (PPSU), thermoset polyurethane, thermoset polyester, epoxy, or silicone rubber. 
     
     
         35 . The composition of  claim 32 , wherein the supercritical fluid includes at least one of carbon dioxide, nitrogen, xenon, ethane, hydrogen, water, methylene chloride, hexane, methane, ethylene, propylene, methanol, ethanol, acetone, or nitrous oxide. 
     
     
         36 . The composition of  claim 32 , wherein the graphene flakes have little or no crystalline imperfection, such that the graphene flakes have a G-band intensity to D-band intensity ratio between about 14 and about 28. 
     
     
         37 . The composition of  claim 32 , wherein the graphene flakes have a thermal stability at a temperature of at least 690° C. 
     
     
         38 . The composition of  claim 32 , wherein the weight ratio of the polymer to the graphene flakes is between about 1 and about 100. 
     
     
         39 . A composition, comprising:
 a polymer; and   a plurality of graphene flakes dispersed in the polymer, the plurality of graphene flakes having a thickness of about 1 to about 10 graphene layers and an aspect ratio between about 50 and about 2,000, the plurality of graphene flakes including charged edges that facilitate hydroxylation and/or carboxylation of the charged edges.   
     
     
         40 . The composition of  claim 39 , wherein the polymer includes at least one of polyethylene, polypropylene, a polyolefin, acrylonitrile butadiene styrene, a poly(meth)acrylate, polystyrene, a polyamide, a polyester, polycarbonate, polyurethane, a polyimide, a polysulfone, a poly(aryl ether ketone), a fluorinated polymer, a thermoplastic elastomer (TPE), thermoplastic polyurethane (TPU), ethylene butyl acrylate (EBA), ethylene-vinyl acetate (EVA), polylactic acid (PLA), polyetherketone (PEK), polyether ether ketone (PEEK), acrylonitrile styrene acrylate (ASA), polyoxymethylene (POM), polyphenylene sulfide (PPS), polyphenylsulfone (PPSU), thermoset polyurethane, thermoset polyester, epoxy, or silicone rubber. 
     
     
         41 . The composition of  claim 39 , further comprising:
 a supercritical fluid disposed in the polymer.   
     
     
         42 . The composition of  claim 41 , wherein the supercritical fluid includes at least one of carbon dioxide, nitrogen, xenon, ethane, hydrogen, water, methylene chloride, hexane, methane, ethylene, propylene, methanol, ethanol, acetone, or nitrous oxide. 
     
     
         43 . The composition of  claim 39 , wherein the plurality of graphene flakes have an average lateral dimension of about 500 nm to about 5 μm.