【摘要】 以PVDF超滤膜为支撑层,PEG为分离层,制备了交联PEG/PVDF复合膜,用于环己醇/环己烷的渗透汽化分离,此复合膜优先脱除环己醇.通过傅立叶红外光谱仪对PEG/PVDF复合膜表面进行结构分析,证实交联后PEG复合膜在1 104.63 cm-1有典型的饱和醚键C—O—C的特征吸收峰;从扫描电镜图看出,PEG在PVDF多孔膜表面形成均匀致密的分离层.将PEG/PVDF复合膜应用于环己醇/环己烷体系,考察了料液浓度和操作温度对膜分离性能的影响以及膜的溶胀性和长时间操作下的稳定性.实验结果表明:随操作温度或料液中环己醇浓度的增加膜的分离因子逐渐减小而渗透通量增大.膜在环己醇中的溶胀度小于6%.在环己醇浓度为2.5%,操作温度80℃,72 h长时间操作下PEG/PVDF复合膜的渗透通量为0.46 kg/(m2.h),分离因子为7.30.更多还原

【Abstract】 Crosslinked PEG/PVDF composite membranes were prepared by using PVDF ultrafiltration membrane as the substrate and PEG dense membrane as the top layer for removing cyclohexanol from cyclohexanol/cyclohexane mixtures by pervaporation.The compositions of the PEG/PVDF composite membranes were characterized by ATR-FTIR.The FT-IR spectra showed that a characteristic band appeared at around 1 104.63 cm-1 in the crosslinked membranes corresponds to the asymmetric stretch of saturated ether bond C—O—C.The surface and profile morphologies of composite membranes were investigated by SEM.The results indicated that a dense layer of crosslinked PEG was formed on the microporous PVDF membrane.The effects of feed concentration and operation temperatures on pervaporation performances of the composite membranes were studied.In addition,the swelling degree and the stableness of the composite membranes were also studied in long operation period.With increasing cyclohexanol concentration in the feed or increasing the operation temperatures,the separation factor decreased but the permeated fluxes increased.The maximum of the swelling degree of the membrane in cyclohexanol was no more than 6%.The PEG/PVDF composite membranes had a flux of 0.46 kg/(m2·h) and separation factor of 7.30 for 2.5% cyclohexanol in the cyclohexanol/cyclohexane mixtures at 80 ℃ during the 72 h operation of pervaporation.更多还原