Study On The Preparation Of [C₃NH₂MIm][PF₆] Modified Pebax Matrix Membrane And The Separation Performance For CO₂

Membrane separation has great potential in capturing CO₂.Mixed matrix membrane membranes（MMMs）can combine the advantages of organic polymers and inorganic materials to exert higher separation performance in the process of separating CO₂,which is one of the focus of current research in the field of membrane separation.However,inorganic nanomaterials tend to agglomerate in the membrane,which leads to the degradation of CO₂separation performance.In order to make up for the above deficiencies,the advantages of the organic phase and the inorganic phase in the MMMs are fully utilized.In this thesis,three additives with good adsorption performance for CO₂are selected to prepare the Pebax matrix membrane.The main research contents of this thesis are as follows:Firstly,two different preparation methods were chosen to graft 1-aminopropyl-3-methylimidazolium hexafluorophosphate（[C₃NH₂MIm][PF₆]）（TIL）onto the surface of Al₂O₃nanoparticles to improve the dispersion of the particles within the membrane and further enhance the separation performance of the gas separation membrane.In this thesis,polyether block polyamide（Pebax1657）was used as the membrane matrix,and TIL,Al₂O₃/PDA-TIL,and Al₂O₃/APTES-SA-TIL were used as fillers to prepare Pebax matrix membranes.The particles and membranes were characterized by SEM,FTIR,XRD,TGA,DSC,and XPS,and the effect of filler incorporation on the membrane gas separation performance was investigated.The results show that:（1）The CO₂permeability and CO₂/N₂selectivity of the prepared Pebax/TIL co-blended membranes were substantially improved by taking advantage of the good affinity of amine（NH₂）for CO₂,with a CO₂permeation flux of 80.66 Barrer and a CO₂/N₂selectivity of 76.09.Compared with the pristine membrane,the CO₂permeability and CO₂/N₂selectivity were improved by 32.90%and 54.22%,respectively.（2）By grafting TIL to polydopamine（PDA）coated nano aluminum oxide（Al₂O₃）,TIL was introduced on the surface of nano Al₂O₃.A new Pebax/Al₂O₃/PDA-TIL MMMs was prepared by blending Al₂O₃/PDA-TIL with Pebax.The SEM test results showed that Al₂O₃/PDA-TIL was uniformly dispersed within the membrane,which indicated that the TIL on the Al₂O₃surface successfully alleviated the agglomeration of Al₂O₃.When the filler content is 0.8 wt%,the gas separation performance of the MMMs is the best,and the CO₂permeability and CO₂/N₂selectivity are increased by 66.62%and 61.37%,respectively.（3）The Pebax/Al₂O₃/APTES-SA-TIL MMMs prepared by modifying nano-Al₂O₃with 3-aminopropyltrimethoxysilane（APTES）and succinic anhydride,respectively,and then grafting TIL onto its surface,increased CO₂permeability and CO₂/N₂selectivity by 41.74%and 61.43%,respectively,compared with the pure membrane.