Electromagnetic interference shielding materials, devices, and methods of manufacture thereof
Described are electromagnetic shields comprising a substrate, a conductive additive, and a binder incorporated with the conductive additive and deposited on the substrate, and methods of making thereof.
1. An electromagnetic shield comprising:
(a) a substrate;
(b) at least about 20% by mass of a conductive additive comprising reduced graphene oxide sheets graphene oxide sheets, carbon black, and graphite; and
(c) a binder incorporated with the conductive additive, and deposited on the substrate.
2. The electromagnetic shield of claim 1 , wherein the substrate comprises a plastic, a metal, a glass, a fabric, or any combination thereof.
3. The electromagnetic shield of claim 2 , wherein the metal comprises copper, aluminum, steel, stainless steel, beryllium, bismuth, chromium, cobalt, gallium, gold, indium, iron, lead, magnesium, nickel, silver, titanium, tin, zinc, or any combination thereof.
4. The electromagnetic shield of claim 2 , wherein the plastic comprises a thermoplastic.
5. The electromagnetic shield of claim 4 , wherein the thermoplastic comprises polyethylene terephthalate, polyglycolic acid, polylactic acid, polycaprolactone, polyhydroxyalkanoate, polyhydroxybutyrate, polyethylene adipate, polybutylene succinate, poly(3-hydroxybutyrate-co-3-hydroxyvalerate), polybutylene terephthalate, polytrimethylene terephthalate, polyethylene naphthalate, or any combination thereof.
6. The electromagnetic shield of claim 1 , wherein the conductive additive is porous.
7. The electromagnetic shield of claim 1 , wherein the conductive additive comprises nanoplatelets, nanofibers, nanotubes, nanoparticles, nanorods, nanowires, nanoflowers, nanoflakes, nanofibers, nanoplatelets, nanoribbons, nanocubes, bipyramids, nanodiscs, nanoplates, nanodendrites, nanoleaves, nanospheres, quantum spheres, quantum dots, nanosprings, nanosheets, or any combination thereof.
8. The electromagnetic shield of claim 1 , wherein the conductive additive further comprises, cabot carbon, a carbon nanotube, a functionalized carbon nanotube, or any combination thereof.
9. The electromagnetic shield of claim 8 , wherein the conductive additive further comprises the carbon nanotube, and wherein the carbon nanotube is a multi-walled nanotube, a single-walled nanotube, or a combination thereof.
10. The electromagnetic shield of claim 8 , wherein the conductive additive further comprises the functionalized carbon nanotube, and wherein the functionalized carbon nanotube is functionalized with hydroxide, carboxylic acid, or both.
11. The electromagnetic shield of claim 8 , wherein the conductive additive comprises the carbon nanotube, and wherein the carbon nanotube has a length of about 0.25 μm to about 4 μm.
12. The electromagnetic shield of claim 8 , wherein the conductive additive comprises a carbon nanotube, wherein the carbon nanotube has a specific surface area of greater than about 60 m 2 /g.
13. The electromagnetic shield of claim 1 , wherein the binder comprises a polymeric binder.
14. The electromagnetic shield of claim 13 , wherein the polymeric binder comprises styrene butadiene rubber, polyvinylidene fluoride, polytetrafluoroethylene, polyvinyl pyrrolidone, ethyl cellulose, polyurethane, polyester, carboxymethyl cellulose, polyurethane, polyester, polyvinyl alcohol, or any combination thereof.
15. The electromagnetic shield of claim 1 having a thickness of about 10 μm to about 2,000 μm.
16. The electromagnetic shield of claim 1 , wherein the conductive additive has a mean particle size of about 2 μm to about 30 μm.
17. The electromagnetic shield of claim 1 , wherein the conductive additive has a specific surface area of about 2 m 2 /g to about 16 m 2 /g.
18. The electromagnetic shield of claim 1 , wherein the conductive additive has a specific surface area of greater than 1,000 m 2 /g.
19. The electromagnetic shield of claim 1 , wherein the coating is configured to be applied to the substrate by air spraying.
20. The electromagnetic shield of claim 1 , comprising at least about 50% by mass of the conductive additive.