Patent ID: 7264650

Claim:
A method of enriching oxygen as compared to nitrogen in a gas, comprising the steps of: (a) contacting a source gas to one side of a semipermeable separation element under pressure, said source gas comprising oxygen and nitrogen, and said semipermeable separation element comprising (i) a porous substrate, and (ii) a film formed on said porous substrate; said film comprising a silicone elastomer and a nonporous nanoparticle filler, said nanoparticle filler comprising particles of from 5 to 100 nanometers in diameter, said film having a thickness of from 0.5 to 50 microns and an oxygen enrichment selectivity of at least 30 over nitrogen; and then; (b) collecting a product gas from the opposite side of said separation element, with the ratio of oxygen to nitrogen being greater in said product gas than in said source gas.