Adhesive compositions containing graphenic carbon particles
Disclosed herein are adhesive compositions comprising (a) a first component; (b) a second component that chemically reacts with said first component; and (c) graphenic carbon particles having an oxygen content of no more than 2 atomic weight percent. Disclosed herein are associated methods for forming the adhesive compositions and applying the adhesive compositions to a substrate to form a bonded substrate.
1. An adhesive composition comprising:
(a) a first component;
(b) a second component that chemically reacts with said first component; and
(c) graphenic carbon particles comprising one or more stacked layers of one-atom-thick planar sheets of sp 2 -bonded carbon atoms that are densely packed in a honeycomb crystal lattice having an oxygen content of no more than 2 atomic weight percent, a substantially curved, curled or buckled morphology, and a Raman spectroscopy 2D/G peak ratio of at least 1.1.
2. The adhesive composition of claim 1 , wherein said graphenic carbon particles are thermally produced.
3. The adhesive composition of claim 1 , wherein said graphenic carbon particles have a thickness, measured in a direction perpendicular to at least one carbon atom layer, of no more than 10 nanometers.
4. The adhesive composition of claim 1 , wherein said graphenic carbon particles have an aspect ratio of greater than 3:1.
5. The adhesive composition of claim 1 , wherein said graphenic carbon particles comprise from 1 to 10 weight percent of the total weight of the adhesive composition.
6. The adhesive composition of claim 1 , wherein said second component chemically reacts with said first component without the need for activation from an external energy source.
7. The adhesive composition of claim 6 , further comprising rubber particles having a core/shell structure.
8. The adhesive composition of claim 1 , wherein a mixture comprising (a) and (c) is stored separately from (b), wherein a shear thinning ratio at 45 degrees Celsius of the mixture is at least 20 percent greater than a shear thinning ratio at 45 degrees Celsius of a comparative mixture comprising component (a) but not including (c) as measured by an Aton-Paar Physica MCR 301 Rheometer with 25 mm plate and 0.7 mm gap.
9. The adhesive composition of claim 1 , wherein a mixture comprising (a) and (c) is stored separately from (b), wherein a viscosity recovery ((T3) at 17 minutes) of the mixture is at least 3 times greater than a viscosity recovery ((T3) at 17 minutes) of a comparative mixture comprising component (a) but not including (c) as measured as a function of time by an Aton-Paar Physica MCR 301 Rheometer with 25 mm plate and 0.7 mm gap.
10. The adhesive composition of claim 1 , wherein a mixture comprising (a) and (c) is stored separately from (b), wherein a Thixotropic Index of the mixture is at least 25 percent greater than the Thixotropic Index of a comparative mixture comprising component (a) but not including (c) as determined by logarithmically comparing the viscosity of the adhesive sample after 7 minutes of recovery versus the viscosity of the sample as it is being applied.
11. The adhesive composition of claim 1 , wherein said second component chemically reacts with said first component after mixing and upon activation from an external energy source.
12. The adhesive composition of claim 11 , wherein said second component (b) comprises a heat activated latent curing agent.
13. The adhesive composition of claim 1 , wherein a 0.5% by weight solution of said graphenic carbon particles in butyl cellosolve has a bulk liquid conductivity of at least 100 microSiemens as measured by a Fisher Scientific AB 30 conductivity meter.
14. A method for forming a bonded substrate comprising:
applying the adhesive composition of claim 1 to a first substrate;
contacting a second substrate to the adhesive composition such that the adhesive composition is located between said first substrate and said second substrate; and
curing the adhesive composition.
15. A coating composition comprising:
a film forming polymer; and
graphenic carbon particles comprising one or more stacked layers of one-atom-thick planar sheets of sp 2 -bonded carbon atoms that are densely packed in a honeycomb crystal lattice having an oxygen content of no more than 2 atomic weight percent, a substantially curved, curled or buckled morphology, and a Raman spectroscopy 2D/G peak ratio of at least 1.1.
16. A coating comprising:
the cured coating composition of claim 15 .
17. An adhesive comprising:
the cured adhesive composition of claim 1 .
18. A method of making a composition comprising:
mixing thermally produced graphenic carbon particles and an adhesive component comprising an epoxy, wherein the graphenic carbon particles comprise one or more stacked layers of one-atom-thick planar sheets of sp 2 -bonded carbon atoms that are densely packed in a honeycomb crystal lattice having an oxygen content of no more than 2 atomic weight percent, a substantially curved, curled or buckled morphology, and a Raman spectroscopy 2D/G peak ratio of at least 1.1.
19. The method of claim 18 , wherein the thermally produced graphenic carbon particles are produced by heating at least one hydrocarbon precursor material capable of forming a two-carbon species in a thermal zone at a temperature of at least 1000° C.
20. The method of claim 18 , wherein the thermally produced graphenic carbon particles are produced by heating a methane precursor material in a thermal zone at a temperature of at least 1000° C.
21. The method of claim 19 , wherein the thermal zone is at a temperature of from greater than 3,500° C. to 20,000° C.
22. The method of claim 20 , wherein the thermal zone is at a temperature of from greater than 3,500° C. to 20,000° C.