疏水SiO2/PTFPMS杂化复合膜的制备及其气体分离性能

为了提高气体分离膜的耐溶胀特性，以多孔聚醚酰亚胺（PEI）为支撑层，采用溶液共混法制备了疏水SiO₂/PTFPMS杂化复合膜，研究了疏水SiO₂质量共混比对膜形态、耐溶胀性以及不同操作压差下的纯气渗透分离性能的影响。光学显微照片显示，当共混比不超过0.018时，杂化膜的透明度较高，表明疏水SiO₂与PTFPMS具有较好的相容性；当SiO₂与PTFPMS的共混比超过0.018时，SiO₂团聚明显。SEM表征结果显示，杂化膜表面光洁，断面杂化涂层紧密贴合支撑层。疏水SiO₂/PTFPMS杂化膜在异辛烷中的溶胀度为0，在乙酸乙酯中的溶胀度比PTFPMS均质膜的下降了11.9%，显示了其优异的耐溶胀性能。在操作压力为1.0 MPa，操作温度为25℃下，SiO₂共混比为0.012时，疏水SiO₂/PTFPMS杂化复合膜的CO₂渗透通量达到最高156.1GPU，CO₂/N₂选择性为15.86。

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.