Defect-free and cross-linked ultra-thin (sub 100 nm) film composite membranes have been prepared. The membrane materials formed exhibited significantly high CO2 permeances of over 1200 GPU as well as excellent CO2/N2 selectivity of over 40.

The release of large quantities of CO 2 into the atmosphere has been linked to global warming and climate anomalies. Membrane processes offer a potentially viable energy-saving alternative for CO 2 capture in comparison with conventional technologies such as amine absorption. However, gas separation membranes that are currently available have insufficiently high permeance (flux) for large scale applications such as the treatment of high volume flue gas with low concentration of CO 2 . Here we demonstrate a class of thin film composite (TFC) membranes, consisting of a high molecular weight amorphous poly(ethylene oxide)/poly(ether-block-amide) (HMA-PEO/Pebax â 2533) selective layer and a highly permeable polydimethylsiloxane (PDMS) intermediate layer which was pre-coated onto a polyacrylonitrile (PAN) microporous substrate. In contrast to the performance of conventional materials, the selective layer of TFC membranes shows super-permeable characteristics and outstanding CO 2 separation performance. This unprecedented result arises from the introduction of HMA-PEOs into the Pebax â 2533 matrix, leading to high CO 2 permeability and flux. These results provide an encouraging direction to further develop TFC membranes for efficient CO 2 capture processes.