Ultrathin silicone/polycarbonate membranes for gas separation processes

Uniform, defect-free silicone/polycarbonate membranes as thin as 0.015 μ have been formed by spreading solutions of the copolymer on water surfaces. The membranes were readily applied to support materials. Composite membranes formed from several laminations of ultrathin membrane on a support were readily handleable and may provide the basis for practical gas separation processes. Two such processes are (1) the production of 30% oxygen-enriched air, which would require less energy than blending air with oxygen from a modern low-temperature air separation plant, and (2) the on-board generation of nitrogen-enriched air for inerting aircraft fuel tank vapor spaces and vent line.