The development of CO_(2)separation membranes with high permeability and high selectivity,as well as ultra-thin selective layers,has always been challenging.Herein,a molecular-scaled co-assembly strategy is employed t...The development of CO_(2)separation membranes with high permeability and high selectivity,as well as ultra-thin selective layers,has always been challenging.Herein,a molecular-scaled co-assembly strategy is employed to fabricate the Pebax-Mo_(132)(Pebax=polyether-block-amide copolymer;Mo_(132)=(NH_(4))_(42)[Mo_(72)^(Ⅵ)Mo_(60)^(Ⅴ)O_(372)(CH_(3)COO)_(30)(H_(2)O)_(72)])membranes.The optimal selfstanding membrane,Pebax-Mo_(132)-5%,shows a CO_(2)permeability of~384 Barrer and an ultra-high ideal CO_(2)/N_(2)selectivity of~244,outperforming most membranes reported in the literature.The CO_(2)permeability and ideal CO_(2)/N_(2)selectivity are increased by 70%and 367%,respectively,compared with the pristine Pebax membrane.A thin-film composite membrane prepared by spin-coating technique on a support membrane with gutter layers also exhibits a CO_(2)permeance of 838 GPU and a CO_(2)/N_(2)selectivity of 136.Such excellent performance can be attributed to the following reasons:(1)strong hydrogen bonding interactions between{Mo_(132)}clusters and Pebax confer excellent interfacial compatibility to the mixed matrix membranes;(2)incorporation of hollow{Mo_(132)}clusters into the Pebax molecular chain decreases the crystallinity of Pebax,and thereby accelerates the chain dynamics and increases the free volume of the membrane;(3)in situ diffuse reflectance infrared Fouriertransform spectroscopy demonstrates that the{Mo_(132)}clusters can effectively catalyze the hydration reaction of CO_(2)and promote the transport of CO_(2);(4)furthermore,the 0.35 nm pores of the crown ether-type{Mo_(9)O_(9)}allow the accurate size sieving of CO_(2)(0.33 nm)and N_(2)(0.36 nm)molecules.展开更多
基金supported by the National Natural Science Foundation of China(22178019,22208013,22378012,22288102)the Fundamental Research Funds for the Central Universities(XK18026,XK1803-05,XK1902)。
文摘The development of CO_(2)separation membranes with high permeability and high selectivity,as well as ultra-thin selective layers,has always been challenging.Herein,a molecular-scaled co-assembly strategy is employed to fabricate the Pebax-Mo_(132)(Pebax=polyether-block-amide copolymer;Mo_(132)=(NH_(4))_(42)[Mo_(72)^(Ⅵ)Mo_(60)^(Ⅴ)O_(372)(CH_(3)COO)_(30)(H_(2)O)_(72)])membranes.The optimal selfstanding membrane,Pebax-Mo_(132)-5%,shows a CO_(2)permeability of~384 Barrer and an ultra-high ideal CO_(2)/N_(2)selectivity of~244,outperforming most membranes reported in the literature.The CO_(2)permeability and ideal CO_(2)/N_(2)selectivity are increased by 70%and 367%,respectively,compared with the pristine Pebax membrane.A thin-film composite membrane prepared by spin-coating technique on a support membrane with gutter layers also exhibits a CO_(2)permeance of 838 GPU and a CO_(2)/N_(2)selectivity of 136.Such excellent performance can be attributed to the following reasons:(1)strong hydrogen bonding interactions between{Mo_(132)}clusters and Pebax confer excellent interfacial compatibility to the mixed matrix membranes;(2)incorporation of hollow{Mo_(132)}clusters into the Pebax molecular chain decreases the crystallinity of Pebax,and thereby accelerates the chain dynamics and increases the free volume of the membrane;(3)in situ diffuse reflectance infrared Fouriertransform spectroscopy demonstrates that the{Mo_(132)}clusters can effectively catalyze the hydration reaction of CO_(2)and promote the transport of CO_(2);(4)furthermore,the 0.35 nm pores of the crown ether-type{Mo_(9)O_(9)}allow the accurate size sieving of CO_(2)(0.33 nm)and N_(2)(0.36 nm)molecules.
