High-efficiency membrane derived from maleic anhydride grafted polypropylene nanocomposite medicated by a series of cyclodextrins for H2/CH4 separation

Mixed-matrix membranes (MMMs) show great potential for application in hydrogen separation study. However, the MMMs prepared by the traditional strategy have the imperfect compatibility of the matrix and fillers, and the non-ideal microstructure, undergoing a trade-off between permeability and selectivity. Herein, we report a new in-situ limited filling method to improve the H 2 /CH 4 separation performance of the maleic anhydride grafted polypropylene (MAPP) membranes medicated by a series of cyclodextrins (CDs). The introduction of CDs can better loosen the MAPP microstructure and ensure that the nanocomposite membranes have excellent H 2 permeabilities. The two-time limited filling can further compensate for the microvoids or defects in the membrane microstructure, thereby improving the H 2 /CH 4 separation stability of the nanocomposite membranes. The H 2 /CH 4 selectivities of the α-CD/MAPP, β-CD/MAPP, MEDβCD/MAPP, and γ-CD/MAPP are 7.1, 5.7, 6.3, and 5.1 times higher than that of pure MAPP membrane, respectively. This work provides a straightforward and effective strategy to fabricate homogeneous MMMs for gas separation.