Preparation Of Photosensitive MOF-filled Mixed Matrix Membrane And Study On SO₂ Separation Performance

Membrane gas separation technology has attracted widespread attention from scientific researchers due to its low energy consumption and easy operation.Among many membrane materials,polymer-inorganic hybrid membranes have become research hotspots in the field of gas membrane separation technology due to their excellent performance advantages.In this work,the purpose was to capture SO₂.Metal-Organic Framework?MOF?was filled into the block polyetheramide?Pebax?1657?polymer matrix to prepare a variety of mixed matrix membranes.The enhancement of SO₂ permeability and selectivity of the membrane were achieved by strengthening the gas transport channel and the dissolution-diffusion mechanism.Desulfurization process of mixed matrix membrane showed dynamic light response characteristics,and the research results are as follows:Regulation of mixed matrix membrane transmission channels and transport mechanisms intensification:by incorporating?functionalized?MOF materials with SO₂affinity groups or sites?NH₂-MIL-53,Azo@NH₂-MIL-53;MOF-199,Azo@MOF-199?into the Pebax matrix,to fabricatemixed matrix membranes.The transport channel was regulated and the transport mechanism were strengthened.First,the introduction of MOF materials with high specific surface area and porosity has constructed a rich SO₂transport channel.In addition,the inherent SO₂ affinity group?affinity site?in MOF increases the affinity of SO₂,which strengthen the solution-diffusion mechanism of mixed matrix membranes.Pebax/Azo@NH₂-MIL-53-20%membrane exhibited a 135%and 94%higher in SO₂ permeability and SO₂/N₂selectivity,respectively in comparison with pristine Pebax membrane.Pebax/Azo@MOF-199-25%membrane showed a 1.98-times higher SO₂ permeability and 1.57-times higher selectivity,which resulted simultaneous enhancements both in SO₂ permeability and selectivity.SO₂ dynamic light capture mechanism:the photoresponse characteristics of azo molecules caused the SO₂ separation process of Pebax/Azo@MOF?MOF=NH₂-MIL-53 or MOF-199?membranes also possessed dynamic light response characteristics.Azo@NH₂-MIL-53-20%and Pebax/Azo@MOF-199-25%membranes are the research objects of the light-controlled SO₂ separation process.The results showed that under Vis conditions,the SO₂ permeability and SO₂/N₂ of MMMs showed higher than under UV conditions,and the SO₂ permeability and SO₂/N₂ selectivity of MMMs decreased,which processwas reversible.The results indicated that the SO₂ separation performance of the two Pebax/azo@MOF membranes showed a significant light response characteristic.