在聚二甲基硅氧烷( PDMS )中掺入开孔MFI沸石纳米片，形成具有异构体选择性的混合基质膜

A mixture of H 2 SO 4 and H 2 O 2 (known as piranha solution) was used to remove organic structure-directing agents (OSDA) from multilamellar MFI zeolite (ML-MFI). An aqueous solution of MFI zeolite nanosheets was obtained via exfoliation of the OSDA-free ML-MFI zeolite through sonication in water followed by purification through sedimentation. The exfoliated MFI zeolite nanosheets were characterized by various techniques, such as X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and porosimetry by cryogenic N 2 adsorption-desorption, indicating that single-layer MFI nanosheets were obtained and the micropores were opened. MFI nanosheets/polydimethylsiloxane (PDMS) mixed matrix membranes (MMMs) were prepared by the solution casting method using the open-pore MFI zeolite nanosheets as the filler and PDMS as the continuous phase. The obtained MMMs exhibited greatly improved butane isomer permeabilities and ideal selectivities for n- butane over i- butane compared to the pure PDMS membrane. An ideal selectivity of 15.7 for n- butane/ i- butane was achieved on the MMM at 1 wt% loading of MFI nanosheets, with a n- butane permeability up to 15615 Barrer.