Gas separation membrane and method of preparing the same

1. A gas separation membrane comprising:

a porous layered support; and

a gas separating active layer which is disposed on the porous layered support and which consists of 2 to 100 layers of a functionalized graphene,

wherein the gas separating active layer is effective to separate H 2 and CO 2 , H 2 and CO, H 2 and CH 4 , H 2 and N 2 , He and N 2 , N 2 and CO 2 , CH 4 and CO 2 , or a combination thereof, and comprises a crack having a width of about 100 nanometers or less.

2. The gas separation membrane of claim 1 , wherein the functionalized graphene is a graphene oxide, a reduced graphene oxide, or a combination thereof.

3. The gas separation membrane of claim 2 , wherein the functionalized graphene has a C/O content ratio of about 1 to about 9.5.

4. The gas separation membrane of claim 1 , wherein a thickness of the gas separating active layer is about 1 nanometer to about 6 micrometers.

5. The gas separating membrane of claim 1 , wherein the functionalized graphene further comprises a nitrogen functional group, a phosphorus functional group, a sulfur functional group, a hydrocarbon functional group, a halogen functional group, or a combination thereof.

6. The gas separating membrane of claim 1 , wherein the functionalized graphene is in the form of a flake.

7. The gas separation membrane of claim 1 , wherein the porous layered support comprises a metal, a ceramic, or a polymer, or a combination thereof.

8. The gas separation membrane of claim 7 , wherein the metal is iron, steel, or a combination thereof.

9. The gas separation membrane of claim 7 , wherein the ceramic is at least one selected from glass, Al 2 O 3 , zirconia, TiO 2 , zeolite, or a combination thereof.

10. The gas separation membrane of claim 7 , wherein the polymer is polysulfone, polyvinylidene fluoride, cellulose, polyacrylonitrile, polyethersulfone, polyimide, or a combination thereof.

11. A gas separator comprising the gas separation membrane of claim 1 .