实验技术与管理2025，Vol.42Issue(10)：83-89,7.DOI:10.16791/j.cnki.sjg.2025.10.010
基于离子液体改性UiO-66的混合基质膜及CO2/N2分离综合实验设计
Comprehensive experimental design of mixed matrix membranes and CO2/N2 separation based on ionic-liquid-modified UiO-66
摘要
Abstract
[Objective]Driven by carbon neutrality needs,the permeability-selectivity trade-off in polymeric membranes for industrial CO2/N2 separation can be solved by developing novel mixed matrix membranes(MMMs)with ionic liquid(IL)-modified metal-organic framework(MOF)fillers.The primary objectives of this work are to(1)synthesize and characterize an IL confined within a functionalized MOF(UiO-66-NH2)to create a synergistic composite filler(IL-UiO-66-NH2),(2)fabricate MMMs by dispersing this filler in a 6FDA-DAM matrix,and(3)systematically evaluate their CO2/N2 separation performance,elucidating underlying enhancement mechanisms.[Methods]Amino-functionalized UiO-66-NH2 was synthesized via a solvothermal method using zirconium tetrachloride and 2-aminoterephthalic acid in N,N-dimethylformamide with acetic acid as a modulator.A superbasic IL,[DBN][3-Methyl Pyr],was synthesized through an equimolar reaction of DBN and 3-methylpyrazole under nitrogen at 40℃.IL-UiO-66-NH2 was prepared using a wet impregnation technique,where UiO-66-NH2 powder was stirred in an ethanolic solution of[DBN][3-Methyl Pyr],followed by centrifugation and drying.The 6FDA-DAM polyimide was synthesized via the polycondensation of 6FDA and DAM in NMP,followed by chemical imidization.MMMs with IL-UiO-66-NH2 loadings ranging from 1 wt%to 9 wt%were fabricated using solution casting in dichloromethane.For comparison,MMMs with pristine UiO-66-NH2 were also prepared.Extensive characterization was performed using various techniques.The permeation properties of pure and mixed gases(CO2:N2=50:50)were measured at 25℃and 1 bar using a constant-volume/variable-pressure setup(Wicke-Kallenbach principle)with Ar sweep gas and gas chromatography analysis.Permeability(Barrer)and selectivity(αCO2/N2)were calculated,and temperature(25-40℃)and pressure(0.1-0.25 MPa)effects were investigated.Solubility and diffusion coefficients were determined for key membranes.[Results]Characterization confirmed successful IL encapsulation within UiO-66-NH2 pores without structural disruption.Fourier transform infrared spectroscopy revealed hydrogen bonding in IL-MOF.N2 adsorption showed a significant reduction in Brunauer-Emmett-Teller surface area from 1000 m2/g for pristine MOF to 352 m2/g for IL-MOF,confirming IL confinement and pore-size tuning,especially in larger pores(7.38 Å and 11.6 Å).IL-UiO-66-NH2 exhibited high CO2 adsorption(24.4 cm3(STP)/g at 298 K,1 bar).The optimal MMM(7wt%IL-UiO-66-NH2)achieved exceptional CO2 permeability of 658.5 Barrer and CO2/N2 selectivity of 23.6(25℃,1 bar),surpassing pure 6FDA-DAM and pristine MOF MMMs.This enhancement stemmed primarily from a 55%increase in solubility selectivity(from 10.99 for PI to 17.07)due to IL-facilitated CO2 adsorption.Diffusion selectivity decreased slightly(from 2.78 to 1.32).Performance remained stable at 40℃but declined significantly above 0.1 MPa due to reduced solubility selectivity and potential plasticization.[Conclusions]Confining superbasic IL[DBN][3-Methyl Pyr]within UiO-66-NH2 created a synergistic filler that enhanced MMM performance through(1)IL basic sites boosting CO2 solubility selectivity,(2)optimized MOF pore size improving sieving,and(3)improved MOF-polymer interfacial compatibility.The resulting 7 wt%IL-UiO-66-NH2/PI MMM exhibited outstanding CO2/N2 separation performance(PCO2=658.5 Barrer,αCO2/N2=23.6),overcoming the permeability-selectivity trade-off.The dominant enhancement mechanism was the IL-driven increase in solubility selectivity.This work provides an effective IL@MOF strategy for advanced flue gas carbon capture membranes.关键词
混合基质膜/CO2/N2分离/离子液体改性/金属有机框架Key words
mixed matrix membranes/CO2/N2 separation/ionic liquids modification/MOF分类
通用工业技术引用本文复制引用
刘思远,刘庆龙,甄玉花,鲁效庆,魏淑贤..基于离子液体改性UiO-66的混合基质膜及CO2/N2分离综合实验设计[J].实验技术与管理,2025,42(10):83-89,7.基金项目
国家自然科学基金面上项目(22471289) （22471289）
山东省本科教学改革研究项目(重点项目)(Z2022177) （重点项目）
中国石油大学(华东)探究性实验项目(TJ-202313) （华东）
中国石油大学(华东)研究生教育教学改革项目(YJG2023052,YJG2024027) （华东）
