Ceramic-supported polymer membranes for pervaporation of binary organic/organic mixtures
Ceramic-supported polymer membranes for pervaporation of binary organic/organic mixtures
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DOI：
10.1016/s0376-7388(02)00521-5
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发表时间：
2003-03
影响因子：
9.5
通讯作者：
Wayne Yoshida;Y. Cohen
中科院分区：
文献类型：
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作者：
Wayne Yoshida;Y. Cohen
制备了氧化铝支撑的聚醋酸乙烯酯（PVAc）和聚乙烯吡咯烷酮（PVP）非对称管式膜，并对甲醇和甲基叔丁基醚（MTBE）二元混合物进行了渗透汽化分离。活性分离层是通过PVAc和PVP在乙烯基硅烷改性的氧化铝基底上的自由基接枝聚合而产生的，其平均天然孔径为50 μ m。分离层由末端锚定的聚合物链的表面相组成，所述聚合物链的估计回转半径比膜孔半径大约4.5-6.8倍。PVP和PVAc接枝的渗透蒸发膜的甲醇分离因子分别达到26和100的值，在研究中测试的甲醇浓度的较低范围（1- 5%v/v）。接枝聚合物链的分离影响是显而易见的，因为天然（未改性）和乙烯基甲硅烷基化的氧化铝膜缺乏对MTBE/甲醇系统的选择性。在1-90和5-90%（v/v）的相应进料甲醇浓度范围内，用PVAc和PVP基膜获得的总渗透通量分别为0.055至1.26和0.55至6.19kg/m2 h。分离和渗透通量之间的折衷是明显的，从渗透通量随着分离因子的增加而降低。
Asymmetric tubular alumina-supported poly(vinyl acetate) (PVAc) and poly(vinyl pyrrolidone) (PVP) membranes were created and characterized by pervaporation separation of binary mixtures of methanol and methyl tert-butyl ether (MTBE). The active separation layer was created by free-radical graft polymerization of PVAc and PVP onto a vinylsilane-modified alumina substrate with an average native pore diameter of 50Å. The separation layer consisted of a surface phase of terminally anchored polymer chains with estimated radius of gyration about a factor of 4.5–6.8 larger than the membrane pore radius. The methanol separation factors for the PVP and PVAc-grafted pervaporation membranes reached values of 26 and 100, respectively, at the lower range of methanol concentrations (1–5% v/v) tested in the study. The separation impact of the grafted polymer chains was apparent given that the native (unmodified) and vinylsilylated alumina membranes lacked selectivity for the MTBE/methanol system. Total permeate flux attained with the PVAc and PVP-based membranes ranged from 0.055 to 1.26 and 0.55 to 6.19kg/m2h, respectively, over the respective feed methanol concentration ranges of 1–90 and 5–90% (v/v). A tradeoff between separation and permeate flux was apparent from the decrease in permeation flux with increasing separation factor.