Highly conductive graphene-based polymer composite
A method was developed to impart a significant enhancement in the electrical conductivity of a graphene/polymer composite by the addition of a non-conducting filler to the insulating polymer that acts as both a toughening agent and dispersion aid.
1. A method of making an electrically conductive composite material, comprising:
dissolving a polymer in a solvent;
making a suspension comprising the dissolved polymer and a non-conductive filler dispersing-aid;
making a suspension comprising individual graphene units;
mixing the two suspensions together;
adding an antisolvent for the polymer to the mixed suspension to precipitate a composite material;
drying the composite material; and
pressing the composite material to remove air and produce a desired shape,
wherein the non-conductive filler dispersing-aid comprises silica or a core-shell rubber and
wherein the non-conducting filler dispersing-aid is present in the range of 5-10 volume percent, and the graphene units are present in the range of 1.5-2.5 volume percent.
2. The method of claim 1 , wherein the polymer is polystyrene.
3. The method of claim 2 , wherein the solvent is N,N-dimethylformamide.
4. The method of claim 2 , wherein the antisolvent is methanol.
5. The method of claim 1 , wherein the graphene units comprise graphene nanoplates.
6. The method of claim 1 , wherein the core-shell rubber has a rubber core and polymer shell.
7. The composition of matter of claim 6 , wherein the rubber is polybutadiene.
8. The composition of matter of claim 6 , wherein the polymer shell is a methylmethacrylate/styrene/acrylate copolymer.
9. The method of claim 1 , wherein the steps of making the suspensions include sonicating the suspensions to disperse the non-conductive filler and graphene units within their respective suspensions.