Graphite oxide and polyacrylonitrile based composite
The present method includes graphene, preferably in the form of flat graphene oxide flakes with, by mass, preferably between 0.5% and 35% PAN. The graphene oxide and conductive-polymer PAN is in a co-suspension in water and is co-deposited on a surface. The deposited PAN with a high-percentage graphene-oxide layer is dried. Our tests have produced electrical conductivities 1000 times more conductive than the PAN by itself. Our testing indicates that using flakes that are flat is essential to getting very high conductivity, and that controlled oxidation is very important in suspending graphene oxide in water.
1. A method of making an electrical and thermal conductor, comprising:
providing microcrystalline graphite;
producing flat graphene oxide (GO) flakes 5 to 50 microns across by simultaneously (1) treating the microcrystalline graphite with one or more oxidizing chemicals and (2) milling the microcrystalline graphite;
preparing a co-suspension of the flat GO flakes and polyacrylonitrile (PAN) in a solvent consisting of dimethylformamide (DMF), wherein the co-suspension comprises between 1% and 25% PAN by mass and between 75% and 90% flat GO flakes by mass;
casting or extruding the co-suspension into a water-containing fluid or into water, wherein the PAN is hydrolyzed, forming a gel that envelops the GO flakes, resulting in a H-PAN/GO material;
injecting the H-PAN/GO material into a mold, resulting in a H-PAN/GO molded structure; and
graphitizing the H-PAN/GO molded structure by heating at 1,500° C. in a mechanical press in an inert atmosphere or a vacuum.
2. The method of claim 1 , wherein the flat GO flakes are 5 to 20 microns across.
3. The method of claim 1 , wherein the flat GO flakes are 5 to 14 microns across.
4. The method of claim 1 , further comprising the step of pressing the H-PAN/GO material through a stylist, or spinneret to form a fiber.
5. A method of fabricating an electronic device comprising a high surface area electrode for an energy storage device by:
providing microcrystalline graphite;
producing flat graphene oxide (GO) flakes 5 to 50 microns across by simultaneously (1) treating the microcrystalline graphite with one or more oxidizing chemicals and (2) milling the microcrystalline graphite;
preparing a co-suspension of the flat GO flakes and polyacrylonitrile (PAN) in a solvent consisting of dimethylformamide (DMF), wherein the co-suspension comprises between 1% and 25% PAN by mass and between 75% and 90% flat GO flakes by mass;
casting or extruding the co-suspension into a water-containing fluid or into water, wherein the PAN is hydrolyzed, forming a gel that envelops the GO flakes, resulting in a H-PAN/GO material;
injecting the H-PAN/GO material into a mold, resulting in a H-PAN/GO molded electrode structure; and
graphitizing the H-PAN/GO molded electrode structure by heating at 1,500° C. in a mechanical press in an inert atmosphere or a vacuum.
6. The method of claim 5 , wherein the GO flakes are 5 to 20 microns across.
7. The method of claim 5 , wherein the GO flakes are 5 to 14 microns across.