An original synthesis strategy for tubular zeolitic imidazolate framework (ZIF) membranes was developed by the deposition of a novel porous amorphous hybrid material prepared by 3-isocyanatopropyltrimethoxysilane (IPTMS) and ZIF-8 crystals onto a coarse macroporous α-Al2O3 tubular support. This porous amorphous hybrid material (ZIF-8-IPTMS) not only strongly adhered to the support but also repaired the defects to make the support surface smooth due to the abundant hydroxyl groups and the appropriate particle size. Using this synthesis strategy, we successfully prepared a high-quality ZIF-8 membrane on an inorganic α-Al2O3 tubular support via the sufficient heterogeneous nucleation sites provided by the amino groups of ZIF-8-IPTMS. This ZIF-8 membrane with an ultrathin thickness of approximately 0.9 μm was prepared, and its ideal H2/CO2 selectivity increased as the temperature increased. The membrane exhibited a competitive selectivity of 13.8 with a remarkably high H2 permeance of 1.46 × 10–5 mol·m–2·s–1·Pa–1 at 90 °C and 0.1 MPa. H2/CO2 binary gas permeation measurements indicated a separation factor of 9.2, and the H2 permeance was maintained at 0.83 × 10–5 mol·m–2·s–1·Pa–1 at 90 °C and 0.1 MPa. This synthesis strategy was also suitable to fabricate ZIF-67 membranes. The ZIF-67 membrane with a thickness of approximately 1.2 μm exhibited a H2/CO2 ideal selectivity of 5.3 and maintained a high H2 permeance of 1.06 × 10–5 mol·m–2·s–1·Pa–1 at 35 °C and 0.1 MPa.
Yin Yang,Juan Liu,Qi Zhou,Siqi Shao,Lingling Zou,Wenjun Yuan,Meihua Zhu,Xiangshu Chen,Hidetoshi Kita
Silicalite-2 membranes were successfully prepared on tubular α-Al2O3supports by secondary hydrothermal synthesis, and the pervaporation performance of the membrane was evaluated by separation of a 5 wt% ethanol/H2O mixture at 60 °C. The effects of templating agent content, water–silicon ratio and crystallization time on the separation performance of Silicalite-2 membranes were investigated. When the TBAOH/SiO2and H2O/SiO2molar ratios of the precursor synthesis solution were 0.2 and 120, a dense Silicalite-2 membrane could be prepared on the surface of the tubular α-Al2O3support after 72 h. The silane coupling agent was utilized to treat the Silicalite-2 membranes, and the effects of silane coupling agent dosage on their properties were also explored. The pervaporation performance of the Silicalite-2 membrane was greatly improved with a 5.7 wt% trimethylchlorosilane (TMCS) solution and the flux and separation factor of the membrane reached 1.75 kg·m−2·h−1and 22 for separation of 5 wt% EtOH/H2O at 60 °C, respectively.
危险品化学品经营许可证（带存储）