CO 2 -selective poly (ether-block-amide)/polyethylene glycol composite blend membrane for CO 2 separation from gas mixtures

• Published in: Environmental science and pollution research international 2021-03
• Main Authors: Taheri, Parisa, Raisi, Ahmadreza, Maleh, Mohammad Salehi
• Format: Article
• Language: English
• ISSN: 1614-7499

This work focuses on the preparation of composite blend membranes based on poly (ether-block-amide) (Pebax-1657) by incorporating polyethylene glycol (PEG) for gas separation applications. The influence of PEG with different molecular weights (PEG600, PEG1500, and PEG4000) at loading content in the range of 10%wt. to 40%wt. was investigated on the microstructure and gas separation performance of the prepared blend membranes. The fabricated membranes were characterized using SEM, XRD, and water contact angle analyses. Based on the experimental results, the blending of low molecular weight PEG (PEG600) into the Pebax-1657 matrix increased the chain mobility of the membrane, led to a smooth microstructure, and improved the hydrophilicity of the blend membranes, as well as enhanced the gas permeability of N , O , CH , and CO , but only slightly affected the ideal selectivity of O /N , CH /N , CO /N , and CO /CH . In contrast, the incorporation of PEG1500 and PEG4000 meaningfully increased the membrane crystallinity, decreased chain mobility, resulted in a rough microstructure, and reduced the blend membranes' hydrophilicity. For CO /N mixture, the Pebax/40%PEG600 membrane had CO permeability of 62.9 Barrer and selectivity of 83.8, while the Pebax/20%PEG600 showed the CO permeability of 63.12 Barrer and selectivity of 23.6 for CO /CH separation.