Polybenzimidazole (PBI)/zeolitic imidazolate frameworks (ZIF-8) mixed matrix membranes for pervaporation dehydration of alcohols
Polybenzimidazole (PBI)/zeolitic imidazolate frameworks (ZIF-8) mixed matrix membranes for pervaporation dehydration of alcohols
复制标题
DOI：
10.1016/j.memsci.2012.05.052
复制
发表时间：
2012-10-01
影响因子：
9.5
通讯作者：
Chung, Tai Shung
中科院分区：
文献类型：
--
作者：
Shi, Gui Min;Yang, Tingxu;Chung, Tai Shung
我们合成了纳米沸石咪唑骨架(ZIF-8)，并将合成的ZIF-8悬浮液直接混合到聚合物涂料中，用于乙醇、异丙醇和丁醇的渗透汽化脱水，制备了形貌均一的聚苯并咪唑(PBI)/ZIF-8混合基质膜(MMMs)，ZIF-8的含量高达58wt%。渗透汽化测试数据表明，PBI/ZIF-8(1：1)MMMS的透水率比原始的PBI膜高一个数量级(14,000-22,000对1200-2300巴雷尔)。由Arrhenius方程计算的表观活化能表明，含33.7wt%ZIF-8纳米粒子的PBI膜的渗透能垒降低了29.2%。结果表明，PBI膜中33.7wt%的ZIF-8使水的透过率提高了4倍，但对水的选择性没有明显降低。PBI膜中58.7wt%的ZIF-8具有很高的透水性，但选择性较低。此外，由于其无机性质，MMMS还显示出有效地抑制乙醇在聚合物基质上的溶胀。蒸汽吸附研究证实，渗透汽化性能的提高主要归因于扩散系数选择性的显著改善。ZIF-8纳米粒子具有较高的热稳定性、耐化学性和与PBI的良好相容性，是提高PBI等低渗透高性能材料整体分离性能的理想填料。(C)2012爱思唯尔B.V.保留所有权利。
We have synthesized nano-sized zeolitic imidazolate frameworks (ZIF-8) and prepared polybenzimidazole (PBI)/ZIF-8 mixed matrix membranes (MMMs) with uniform morphology comprising ZIF as high as 58 wt% by directly mixing the as-synthesized ZIF-8 suspension into the polymer dope for pervaporation dehydration of ethanol, isopropanol (IPA) and butanol. Pervaporation test data show that the water permeability of PBI/ZIF-8 (1:1) MMMs is about one order higher than the original PBI membrane (14,000-22,000 vs. 1200-2300 Barrer). The apparent activation energy calculated from the Arrhenius equation indicates that there is a 29.2% reduction of energy barrier for penetrant transports for PBI membranes consisting of 33.7 wt% ZIF-8 nano-particles. As a result, the 33.7 wt% ZIF-8 in PBI membrane increases water permeability four times without much decrease in selectivity for water. The 58.7 wt% ZIF-8 in PBI membrane has a very high water permeability but a relatively low selectivity. Furthermore, the MMMs also show effectiveness in suppressing ethanol-induced swelling on the polymeric matrix owing to its inorganic properties. Vapor sorption studies confirm that the enhancement of pervaporation performance is primarily attributed to the significant improvement in diffusivity selectivity. With high thermal stability, chemical resistance and excellent compatibility with PBI, ZIF-8 nano-particles are promising fillers for enhancing the overall separation performance of low permeability but high performance materials like PBI. (c) 2012 Elsevier B.V. All rights reserved.