Preparation Of Nanoparticles Filled Polymer Mixed Matrix Membranes For Gas Separation

Gas separation membranes technology using selective and polymeric membranematerial have received significant attention as a promising technology for gas purificationprocesses for the separation of gaseous mixtures. However, due to the receipt of the Robesoncurve, there is a trade-off limitation between permeability and selectivity. In the past fewdecades, a lot of researchers proposed preparation of organic/inorganic mixed matrixmembranes （MMMs） with the advantages of combining the benefits of both organic andinorganic membrane materials. MMMs has became represent a viable commercial alternative.In this paper, using blending method, the nanoparticle silica was directed into the PESpolymer. The PES/SiO₂hollow fiber MMMs were prepared by dry/wet phase separationmethod. The distribution of the silica nanoparticle in PES was observed by scanning electronmicroscopy （SEM）. The PES/SiO₂hollow fiber MMMs properties such as the mechanicalproperties, gas separation, storage time and different post-processing method werecharacterized. The results show that, in a vacuum drying conditions, the oxygen permeabilityis approximately five times higher, the nitrogen permeability is over nine times greater, thecarbon dioxide permeability is nearly two times upper, the methane permeability is close tofour times superior and the hydrogen permeability is almost two times than in a pure PEShollow fiber membrane. Meanwhile, the results showed that the MMMs decrease the O₂/N₂，CO₂/CH₄and H₂/N₂selectivity compared to the unfilled membranes. During physical aging,the gas permeability and selectivity decrease, while finally both come to a state ofequilibrium.In this dissertation, PES/SiO₂hollow fiber MMMs were prepared by sol–gel method,TEOS as precursor, ethanol as solvent, the acid as catalyst of hydrolysis and condensation.The MMMs were characterized using EDX, SEM and the mechanical properties. The EDXspectra confirmed that the nanoparticle silica had taken place. Experimental results show that,in a vacuum drying conditions, not reserved for air-gap, acetic acid as catalyst of hydrolysisand condensation, the performance of PES/SiO₂hollow fiber MMMs were studied for gasseparation with a filler content between0and6Vol.%. The pure-gas permeability of unfilledPES and silica-filled PES hollow fiber MMMs with varying silica volume fraction at25℃and0.5MPa were investigated. The gas permeability of O₂, N₂, CO₂, CH₄and H₂was18.69, 4.36,97.72,4.82and443.91, respectively. The O₂/N₂, CO₂/CH₄and H₂/N₂separation factorwas4.29,20.27and101.81. The gas permeability and selectivity of MMMs were stablegradually, in the store within60days. The young’s modulus is two point five times comparedto the PES hollow fiber membrane.