▎ 摘　　要

NOVELTY - The gas separation membrane comprises: a porous layered support (21); and a gas separating active layer (22), which is arranged on the porous layered support and comprises 1-100 layers of a functionalized graphene. The functionalized graphene has a carbon/oxygen content ratio of 1-9.5. A thickness of the gas separating active layer is 1 nm to 6 mu m. The gas separating active layer further comprises a crack having a width of less than or equal to 100 nm. The functionalized graphene is in the form of a flake. The porous layered support comprises a metal, a ceramic, a glass and/or a polymer. USE - The membrane is useful in a gas separator for separating gas such as hydrogen (H2) and carbon dioxide (CO2), H2 and carbon monoxide, H2 and methane (CH4), H2 and nitrogen (N2), helium and N2, N2 and CO2 and/or CH4 and CO2 (all claimed) for industrial use. ADVANTAGE - The gas separation membrane allows effective and economic separation of the gas, and can be manufactured in a convenient manner with high gas permeation rate and excellent selectivity, processability and modularity and without any cracks. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a method of preparing a gas separation membrane. DESCRIPTION OF DRAWING(S) - The diagram shows a schematic cross sectional view of a gas separation membrane. Porous layered support (21) Gas separating active layer. (22)