Graphenic carbon particle co-dispersions and methods of making same
Co-dispersions of different types of graphenic carbon particles are produced using a polymeric dispersant. A portion of the graphenic carbon particles may be thermally produced. The polymeric dispersant may include an anchor block comprising glycidyl (meth)acrylate, 3,4-epoxycyclohexylmethyl(meth)acrylate, 2-(3,4-epoxycyclohexyl)ethyl(meth)acrylate, allyl glycidyl ether and mixtures thereof, reacted with a carboxylic acid comprising 3-hydroxy-2-naphthoic acid, para-nitrobenzoic acid, hexanoic acid, 2-ethyl hexanoic acid, decanoic acid and/or undecanoic acid. The polymeric dispersant may also include at least one tail block comprising at least one (meth)acrylic acid alkyl ester.
1. A co-dispersion comprising:
a solvent;
at least one polymeric dispersant; and
at least two types of graphenic carbon particles having different particle size distributions and comprising planar sheets having average aspect ratios of greater than 3:1 co-dispersed in the solvent and the polymeric dispersant.
2. The co-dispersion of claim 1 , wherein one of the types of graphenic carbon particles comprises thermally produced graphenic carbon particles.
3. The co-dispersion of claim 2 , wherein the thermally produced graphenic carbon particles comprise from 4 to 40 weight percent of the total amount of the graphenic carbon particles.
4. The co-dispersion of claim 2 , wherein the thermally produced graphenic carbon particles comprise from 10 to 30 weight percent of the total amount of the graphenic carbon particles.
5. The co-dispersion of claim 1 , wherein the weight ratio of graphenic carbon particles to the polymeric dispersant is from 1:10 to 10:1.
6. The co-dispersion of claim 1 , wherein the at least one polymeric dispersant comprises:
a) an anchor block comprising glycidyl (meth)acrylate, 3,4-epoxycyclohexylmethyl(meth)acrylate, 2-(3,4-epoxycyclohexyl)ethyl(meth)acrylate, allyl glycidyl ether or mixtures thereof, reacted with a carboxylic acid comprising 3-hydroxy-2-naphthoic acid, para-nitrobenzoic acid, hexanoic acid, 2-ethyl hexanoic acid, decanoic acid and/or undecanoic acid; and
b) at least one tail block comprising at least one (meth)acrylic acid alkyl ester.
7. The co-dispersion of claim 6 , wherein the anchor block comprises glycidyl (meth)acrylate.
8. The co-dispersion of claim 7 , wherein the at least one tail block comprises at least two (meth)acrylic acid alkyl esters.
9. The co-dispersion of claim 7 , wherein the at least one tail block comprises methoxy poly(propylene glycol) mono (meth)acrylate.
10. The co-dispersion of claim 1 , further comprising at least one film-forming resin.
11. The co-dispersion of claim 10 , wherein the at least one film forming resin comprises epoxy resins, acrylic polymers, polyester polymers, polyurethane polymers, polyamide polymers, polyether polymers, bisphenol A based epoxy polymers, polysiloxane polymers, styrenes, ethylenes, butylenes, copolymers thereof, or combinations thereof.
12. The co-dispersion of claim 10 , wherein a cured coating deposited from the co-dispersion has an electrical conductivity of at least 1 S/m.
13. The co-dispersion of claim 10 , wherein the co-dispersion has an electrical conductivity of at least 20,000 S/m.
14. The co-dispersion of claim 10 , wherein the weight ratio of graphenic carbon particles to film-forming resin is from 0.1:100 to 10:1.
15. The co-dispersion of claim 10 , wherein the weight ratio of graphenic carbon particles to film-forming resin is from 1:100 to 7:1.
16. The co-dispersion of claim 1 , wherein the solvent comprises an organic solvent comprising n-methyl-2-pyrrolidone, n-butyl acetate, propylene glycol monomethylether, 4-hydroxybutyric acid gamma-lactone, ethanol, 2-butoxyethanol, acetone, toluene, xylene, aromatic solvent, methyl ether propylene glycol acetate and/or methyl amyl ketone or a combination thereof.
17. The co-dispersion of claim 1 , wherein the solvent comprises an organic solvent comprising n-methyl-2-pyrrolidone, n-butyl acetate, propylene glycol monomethylether or a combination thereof.
18. The co-dispersion of claim 1 , wherein the solvent comprises water.
19. The co-dispersion of claim 18 , wherein the solvent further comprises an organic solvent.
20. The co-dispersion of claim 16 , wherein the organic solvent comprises propylene glycol monomethylether and/or ethanol.
21. An electrically conductive coating produced from a dried co-dispersion comprising:
a solvent;
at least one polymeric dispersant; and
at least two types of graphenic carbon particles having different particle size distributions and comprising planar sheets having average aspect ratios of greater than 3:1 co-dispersed in the solvent and the polymeric dispersant.
22. The electrically conductive coating of claim 21 , further comprising a film-forming resin.
23. The electrically conductive coating of claim 22 , wherein one of the types of graphenic carbon particles comprises thermally produced graphenic carbon particles.
24. The electrically conductive coating of claim 23 , wherein the thermally produced graphenic carbon particles comprise from 10 to 30 weight percent of the total amount of the graphenic carbon particles.
25. The electrically conductive coating of claim 24 , having an electrical conductivity at least 10,000 S/m.
26. A method comprising co-dispersing at least two types of graphenic carbon particles having different particle size distributions and comprising planar sheets having average aspect ratios of greater than 3:1 in a solvent in the presence of at least one polymeric dispersant to thereby produce a co-dispersion of the at least two types of graphenic carbon particles in the solvent and the at least one polymeric dispersant.