Maleh Mohammad Salehi, Raisi Ahmadreza
Department of Chemical Engineering, Amirkabir University of Technology (Tehran Polytechnic) Hafez Ave. P. O. Box 15875-4413 Tehran Iran
RSC Adv. 2019 May 17;9(27):15542-15553. doi: 10.1039/c9ra01654f. eCollection 2019 May 14.
A functional moderate selective layer mixed matrix membrane (F-MSL-MMM) is a promising candidate to obtain superior separation of industrial gases, compared to commonly mixed matrix membranes. In this work, highly permeable and selective F-MSL-MMMs consisting of a moderate Pebax layer filled with functionalized NaX nano-zeolite over a microstructure PES support layer with the desired operating stability were prepared to investigate the effect of -COOH surface functionalization on the NaX nano-zeolites and to achieve the efficient separation of CO/N, CO/CH and CH/N gas mixtures. It was found that modification of the nano-zeolite had significant effects on the morphology and gas separation performance of the F-MSL-MMMs. The incorporation of NaX-COOH nano-zeolites into the polymeric matrix showed superior dispersion, capabilities and interactions over unmodified zeolite without any defects. In addition, based on gas permeation results at various filler loadings and feed pressures, different trends were observed for the permeability and selectivity of the F-MSL-MMMs. Combination of NaX up to 1.5% into the moderate selective layer enhanced the CO permeability (187.76 barrer) and CO/N (288.86), CO/CH (57.41) and N/CH (5.03) selectivities at 6 bar.
与普通混合基质膜相比，功能型适度选择性层混合基质膜（F-MSL-MMM）是实现工业气体卓越分离的一种很有前景的材料。在本研究中，制备了具有高渗透性和选择性的F-MSL-MMM，其由填充有功能化NaX纳米沸石的适度Pebax层和具有所需操作稳定性的微观结构PES支撑层组成，以研究-COOH表面功能化对NaX纳米沸石的影响，并实现CO/N₂、CO/CH₄和CH₄/N₂气体混合物的高效分离。研究发现，纳米沸石的改性对F-MSL-MMM的形态和气体分离性能有显著影响。将NaX-COOH纳米沸石掺入聚合物基体中，与未改性的沸石相比，显示出优异的分散性、性能和相互作用，且无任何缺陷。此外，基于不同填料负载量和进料压力下的气体渗透结果，观察到F-MSL-MMM的渗透率和选择性呈现不同趋势。在适度选择性层中掺入高达1.5%的NaX，在6 bar压力下，可提高CO渗透率（187.76 Barrer）以及CO/N₂（288.86）、CO/CH₄（57.41）和N₂/CH₄（5.03）的选择性。
