Patent ID: 8911540

Claim:
A gas separation membrane comprising: an axially oriented, coextruded multilayer film that has a CO 2 /O 2 selectivity of at least about 4 and a flux of at least about 20 GPU, the axially oriented, coextruded multilayer film including at least one axially oriented, coextruded first polymer layer of a first polymer material and at least one axially oriented, coextruded second polymer layer of a second polymer material, the at least one axially oriented, coextruded first polymer layer having a first permeability (P 1 ) prior to axial orientation and a second permeability (P 2 ) after axially orientation less than or equal to the first permeability (P 1 ), the at least one axially oriented, coextruded second polymer layer having a first permeability (P 1a ) prior to axial orientation and a second permeability (P 2a ) after axial orientation that is substantially greater than the first permeability (P 1a ) and the second permeability (P 2 ).