Preparation of composite poly(ether block amide) membrane for CO2 capture

In this study, a poly(ether block amide) (Pebax 1657) composite membrane applied for CO2 capture was prepared by coating Pebax 1657 solution on polyacrylonitrile (PAN) ultrafiltration membrane. Ethanol/water mixture was used as the solvent of Pebax and the effects of ethanol/water mass ratios and Pebax concentration on the permeation properties of composite membrane were studied. To enhance the composite membrane permeance, the gutter layer, made from reactive amino silicone crosslinking with polydimethylsiloxane (PDMS), was designed. The influence of crosslinking degree of the gutter layer on membrane performance was investigated. As a result, a Pebax/amino-PDMS/PAN multilayer membrane with hexane resistance was developed, showing CO2 permeance of 350 GPU and CO2/N2 selectivity over 50. The blend of polyethylene glycol dimethyl ether (PEG-DME) with Pebax as coating material was studied to further improve the membrane performance. After being combined with PEG-DME additive, CO2 permeance of the final Pebax-PEG-DME/amino-PDMS/PAN composite membrane reached 400 GPU above with CO2/N2 selectivity over 65.

Gutter layer made from cross-linked amino-PDMS not only overcame pore penetration problem during composite membrane preparation, but also showed good hexane resistance. The novel gutter layer led to composite Pebax membrane with good performance on CO2 capture.Figure optionsDownload full-size imageDownload as PowerPoint slide