Separation membranes formed from perforated graphene and methods for use thereof
Perforated graphene sheets can be used in forming separation membranes. Separation membranes of the present disclosure, which can be used in gas separation processes in some embodiments, can include one or more polymer layers and one or more layers of perforated graphene. Methods for separating a gas mixture can include contacting a gas mixture with the separation membranes, and transiting one or more of the gases through the perforated graphene so as to affect separation.
1. A composite membrane for separation of a first gas from a second gas; said separation membrane comprising:
at least one dense polymeric membrane characterized by a permeability for said first gas greater than or equal to 7.5×10 −11 cm 3 cm −2 s −1 kPa −1 ;
at least one layer of a perforated two-dimensional material; and
a plurality of dielectric layers electrically connected to a voltage source,
wherein the plurality of dielectric layers are arranged to charge the at least one layer of the perforated two-dimensional material to control the movement of particles contained within the first gas and particles contained within the second gas through the at least one layer of the perforated two-dimensional material,
wherein said composite membrane is arranged to provide preferential transport of said first gas relative to said second gas through said at least one dense polymer membrane and said at least one layer of said perforated two-dimensional material,
wherein the at least one dense polymeric membrane is configured to provide preferential transport of the first gas relative to the second gas by solution-diffusion, and
wherein the at least one layer of the perforated two-dimensional material is configured to provide preferential transport of the first gas relative to the second gas by molecular separation.
2. The composite membrane of claim 1 , wherein a net gas separation selectivity for said first gas relative to said second gas is greater than or equal to 100.
3. The composite membrane of claim 1 , wherein each of said dense polymeric membranes independently has a thickness less than or equal to 50 microns.
4. The composite membrane of claim 1 , wherein each of said dense polymeric membranes independently comprises a fluorocarbon, hydrocarbon, polysilicone, polyimide, cellulose acetate, polysulfone, polyethersulfone, and polycarbonate or any combination of these.
5. The composite membrane of claim 1 , wherein each of said layers of perforated two-dimensional material is independently characterized by a thickness selected from the range of 0.3 to 5 nm.
6. The composite membrane of claim 1 , wherein each of said layers of perforated two-dimensional material is independently characterized by a plurality of holes independently having cross sectional dimensions less than or equal to 10 angstroms.
7. The composite membrane of claim 6 , wherein said plurality of holes independently have cross sectional dimensions selected over the range of 3 to 5 angstroms.
8. The composite membrane of claim 1 , wherein each of said layers of perforated two-dimensional material independently comprises graphene, a graphene-based material, a transition metal dichalcogenide, molybdenum sulfide, α-boron nitride, silicone, germanene, or a combination thereof.
9. The composite membrane of claim 1 , wherein each of said layers of perforated two-dimensional material independently comprises a perforated graphene-based material.
10. The composite membrane of claim 9 , wherein said perforated graphene-based material comprises single-layer graphene or multi-layer graphene.
11. The composite membrane of claim 1 , wherein the at least one dense polymeric membrane and the at least one layer of said perforated two-dimensional material are provided in physical contact with each other or separated by one or more intermediate structures provided in physical contact with said at least one dense polymeric membrane and said at least one layer of said perforated two-dimensional material.
12. The composite membrane of claim 1 , wherein said at least one dense polymeric membrane and said at least one layer of said perforated two-dimensional material are provided in a stacked multilayer geometry.
13. The composite membrane of claim 12 , wherein said stacked multilayer geometry comprises a first dense polymeric membrane in physical contact with a first layer of said perforated two-dimensional material.
14. The composite membrane of claim 13 , wherein said stacked multilayer geometry further comprises a second dense polymeric membrane wherein said first layer of said perforated two-dimensional material is provided between, and in physical contact with, said first and second dense polymeric membranes.
15. A method for separating a first gas from a second gas; said method comprising the steps of:
providing a composite membrane comprising:
at least one dense polymeric membrane characterized by a permeability for said first gas greater than or equal to 7.5×10 −11 cm 3 cm −2 s −1 kPa −1 ;
at least one layer of a perforated two-dimensional material; and
a plurality of dielectric layers electrically connected to a voltage source; and
contacting an external surface of said composite membrane with said first gas and said second gas;
wherein the plurality of dielectric layers are arranged to charge the at least one layer of the perforated two-dimensional material to control the movement of particles contained within the first gas and particles contained within the second gas through the at least one layer of the perforated two-dimensional material,
wherein said composite membrane provides preferential transport of said first gas relative to said second gas through said at least one dense polymer membrane and said at least one layer of perforated two-dimensional material, thereby separating said first gas from said second gas,
wherein the at least one dense polymeric membrane is configured to provide preferential transport of the first gas relative to the second gas by solution-diffusion, and
wherein the at least one layer of the perforated two-dimensional material is configured to provide preferential transport of the first gas relative to the second gas by molecular separation.
16. The method of claim 15 , wherein methane is said second gas and said first gas is selected from the group consisting of CO 2 , H 2 O, H 2 S or any combination of these.
17. The method of claim 15 , wherein said method is carried out at a temperature at said external surface selected over the range of 200 K to 600 K.
18. The composite membrane of claim 1 , wherein the at least one layer of the perforated two-dimensional material is chemically functionalized.