(a) The gas separation module coupled with electric field. (b) SEM images of the cross-section of ZIF-8 layer. Color code of EDXS (bottom): blue: Zn; green: Al. (c) Alkene-alkane separation performances of ZIF-8 membranes switched by electric field of 500 V/mm. Reproduced from Ref. [32
] with permission from the American Association for the Advancement of Science, copyright 2017. (d) Illustration of the convective circulation synthesis loop. (e) SEM images of the surface (top) and cross-section (bottom) of a ZIF-8 membrane. (f) A wide comparison of membranes for C3
separation. Reproduced from Ref. [35
] with permission from Wiley, copyright 2018.