Preparation and gas separation performance of hydrophobic SiO2/PTFPMS hybrid composite membrane

To improve the solvent resistance property of gas separation membrane, a hydrophobic SiO2/polytrifluoropropylsiloxane (PTFPMS) hybrid composite membrane was fabricated on a porous polyetherimide (PEI) support with solution blending method. The effects of mass ratio of hydrophobic SiO2 to PTFPMS on the membrane morphology, solvent resistance, and gas separation performance of the hydrophobic SiO2/PTFPMS hybrid composite membrane were investigated. The optical microscope images show good miscibility between SiO2 and PTFPMS with the increase of blend ratio till 0.018. At blend ratios higher than 0.018, SiO2 particles exhibit obvious aggregation in the hybrid membrane. SEM images show that no obvious defect is on the surface of the SiO2/PTFPMS selective layer that is closely stuck on the PEI support. The swelling degree of the hydrophobic SiO2/PTFPMS hybrid homogeneous film is 0 in nonpolar solvent octane and is declined by 11.9% in polar solvent ethyl acetate compared with PTFPMS homogeneous film, indicating the improved solvent resistance of the SiO2/PTFPMS hybrid homogeneous film. The CO2 gas permeation rate can reach as high as 156.1 GPU and the selectivity of CO2/N2 is 15.86 when the blend ratio of SiO2 is 0.012 under the transmembrane pressure difference up to 1.0 MPa. © All Rights Reserved.