【摘要】 制备了以聚偏氟乙烯PVDF超滤膜为底膜的聚四氟乙烯PTFE超细粉体填充聚二甲基硅氧烷PDMS复合膜,并用于氯仿水溶液体系的渗透汽化。采用SEM和接触角分析研究了膜结构及表面性能。研究了PTFE:PDMS质量比、料液流速、料液浓度对渗透汽化性能的影响;采用串联阻力模型分析了渗透汽化氯仿水溶液的传质过程。研究表明,填充PTFE提高了PDMS膜渗透汽化性能;流量大于200 mL min 1时渗透汽化传质阻力主要由膜阻力控制;在流速低于200 mL min 1时,浓差极化产生的氯仿传质边界层阻力最大可达膜阻力的29倍。更多还原

【Abstract】 A novel PDMS composite membrane filled with micron PTFE powder and using PVDF ultration membrane as the support layer was prepared for the pervaporation of chloroform from water.The structure and the performance of the composite membranes were characterized by scanning electron microscope(SEM) and contact angle.The effects of mass ratio of PTFE and PDMS,feed flow rate and feed concentration on the pervaporation of the composite membrane were studied.The resistance-in-series model was employed to study the transfer characteristics.From experimental data it can be concluded that the addition of PTFE can enhance pervaporation performance of PDMS membrane for the separation of chloroform from water.When the feed flow rate is greater than 200 mL min 1,the membrane resistance controls the rate of permeation mass transfer.But when the feed flow rate is below 200 mL min 1,the boundary layer resistance resulted from concentration polarization is 29 times as big as the membrane resistance.更多还原