Mixed Matrix Silicone and Fluorosilicone/Zeolite 4A Membranes for Ethanol Dehydration by Pervaporation
Mixed Matrix Silicone and Fluorosilicone/Zeolite 4A Membranes for Ethanol Dehydration by Pervaporation
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DOI：
10.1080/01496395.2012.719057
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发表时间：
2013-01
影响因子：
2.8
通讯作者：
G. Lin;Michael Abar;L. Vane
中科院分区：
文献类型：
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作者：
G. Lin;Michael Abar;L. Vane
评估了使用标准硅橡胶聚二甲基硅氧烷 (PDMS) 和氟硅橡胶聚三氟丙基甲基硅氧烷 (PTFPMS) 制备的均质和混合基质膜通过全蒸发使乙醇脱水的能力。尽管 PDMS 通常被认为是渗透蒸发中的基准疏水膜材料，但对于 50°C 下含有 80/20 w/w 乙醇/水的进料，发现纯 PDMS 膜的水/乙醇摩尔选择性渗透率为 0.89，表明对水有轻微的选择性。 PTFPMS 中的氟化基团将水-乙醇选择性渗透性提高至 1.85，但将水渗透率从 PDMS 中的 9.7 × 10−12 kmol·m/m2·s·kPa 降低至 5.1 × 10−12 kmol·m/m2·s·kPa（分别为 29,000 和 15,200 Barrer）。这些透水性很有吸引力，特别是因为当进料中的水浓度降低时，橡胶材料不应经历大多数标准脱水膜观察到的透水性急剧下降。然而，水选择性低于大多数应用所需的选择性。将亲水性沸石 4A 颗粒负载到 PDMS 和 PTFPMS 基质中，以提高水的选择性并进一步提高水的渗透性。 PTFPMS/沸石 4A 混合基质膜的水-乙醇选择性渗透率高达 11.5，水渗透率高达 23.2 × 10−12 kmol·m/m2·s·kPa，比未填充的 PTFPMS 膜高 6 倍。
The ability of homogeneous and mixed matrix membranes prepared using standard silicone rubber, poly(dimethylsiloxane) (PDMS), and fluorosilicone rubber, poly(trifluoropropylmethylsiloxane) (PTFPMS), to dehydrate ethanol by pervaporation was evaluated. Although PDMS is generally considered to be the benchmark hydrophobic membrane material in pervaporation, water/ethanol molar permselectivity of a pure PDMS membrane was found to be 0.89 for a feed containing 80/20 w/w ethanol/water at 50°C, indicating a slight selectivity for water. Fluorinated groups in PTFPMS improved the water-ethanol permselectivity to 1.85, but decreased the water permeability from 9.7 × 10−12 kmol · m/m2 · s · kPa in PDMS to 5.1 × 10−12 kmol · m/m2 · s · kPa (29,000 and 15,200 Barrer, respectively). These water permeabilities are attractive, particularly since the rubbery materials should not experience the steep declines in water permeability observed with most standard dehydration membranes as water concentration in the feed decreases. However, the water selectivity is lower than desired for most applications. Particles of hydrophilic zeolite 4A were loaded into both PDMS and PTFPMS matrices in an effort to boost water selectivity and further improve water permeability. Water-ethanol permselectivities as high as 11.5 and water permeabilities as high as 23.2 × 10−12 kmol · m/m2 · s · kPa were observed for the PTFPMS/zeolite 4A mixed matrix membranes−6 times higher than for the unfilled PTFPMS membrane.