Cross-linked mixed matrix membranes consisting of carboxyl-functionalized multi-walled carbon nanotubes and P84 polyimide for organic solvent nanofiltration (OSN)
Cross-linked mixed matrix membranes consisting of carboxyl-functionalized multi-walled carbon nanotubes and P84 polyimide for organic solvent nanofiltration (OSN)
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DOI：
10.1016/j.seppur.2017.06.021
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发表时间：
2017-10-02
影响因子：
8.6
通讯作者：
Chung, Tai-Shung
中科院分区：
文献类型：
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作者：
Farahani, Mohammad Hossein Davood Abadi;Hua, Dan;Chung, Tai-Shung
在本研究中，我们制备了由羧基功能化多壁碳纳米管（MWCNTs-COOH）和P84聚酰亚胺组成的混合基质膜（MMMs），通过1,6-己二胺（HDA）的化学交联，用于有机溶剂纳滤（OSN）。适度退火也用于控制孔径，以获得更好的溶质抑制。在P84中掺入亲水性碳纳米管不仅改善了液体的吸附和运输，而且增加了膜的孔隙率和孔径。结果，水、乙醇和异丙醇在mmmm上的渗透率随着MWCNTs-COOH负载的增加而增加，最高可达0.075 wt.%。然而，高负荷的MWCNTs-COOH会降低分离性能。含有0.05 wt.% MWCNTs-COOH的交联MMM对玫瑰碱（1017.65 Da）的拒绝率为85%，而乙醇透过率为9.6 lmi -1，中心点条（-1）为5 bar。有趣的是，玫瑰花在异丙醇溶液中的拒斥率高于在乙醇溶液中的拒斥率（即，99%对85%）。在3/1 EG/PEG400（重量比）溶液中在150℃下进行热退火后，所得膜（MMM中含有0.05 wt.% MWCNTs-COOH）在乙醇溶液中对小染料分子（几乎100%对Safranin 0染料分子，350.85 Da）表现出最高的拒绝性。制备的膜之间存在明显的阻隔性和渗透性之间的权衡关系，其中随着MWCNTs-COOH的加入，阻隔性增强，而渗透性减弱；然而，在退火膜中观察到相反的趋势。(C) 2017 Elsevier B.V.版权所有
We have fabricated mixed matrix membranes (MMMs) consisting of carboxyl-functionalized multi walled carbon nanotubes (MWCNTs-COOH) and P84 polyimide in this study for organic solvent nanofiltration (OSN) with the aid of chemical cross-linking by 1,6-hexanediamine (HDA). A moderate annealing is also used to manipulate the pore size for a better solute rejection. The incorporation of hydrophilic carbon nanotubes into P84 not only improves liquid sorption and transport but also increases membrane porosity and pore size. As a result, the permeances of water, ethanol, and isopropanol across the MMMs increases with an increase in MWCNTs-COOH loading up to 0.075 wt.%. However, a higher loading of MWCNTs-COOH reduces the separation performance. The cross-linked MMM comprising 0.05 wt.% MWCNTs-COOH has a rejection of 85% to rose bengal (1017.65 Da) while ethanol permeance is 9.6 LMI-I center dot bar(-1) at 5 bar. Interestingly, the rejection of rose bengal in isopropanol solutions is higher than that in ethanol solutions (i.e., 99 vs. 85%). After thermal annealing at 150 degrees C in a 3/1 EG/PEG400 (weight ratio) solution, the resultant membranes (MMM comprising 0.05 wt.% MWCNTs-COOH) show superlative rejections to small dye molecules (almost 100% to Safranin 0 dye molecules, 350.85 Da) in ethanol solutions. There is an obvious trade-off between rejection and permeance among the fabricated membranes, in which, the permeance enhancement and rejection diminishing occurred with the addition of MWCNTs-COOH; however, a vice-versa trend was observed in annealed membranes. (C) 2017 Elsevier B.V. All rights reserved.