Cross-Linking with Diamine Monomers To Prepare Composite Graphene Oxide-Framework Membranes with Varying d-Spacing

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• 作者：Wei-Song Hung ; Chi-Hui Tsou ; Manuel De Guzman ; Quan-Fu An ; Ying-Ling Liu ; Ya-Ming Zhang ; Chien-Chieh Hu ; Kueir-Rarn Lee ; Juin-Yih Lai
• 刊名：Chemistry of Materials
• 出版年：2014
• 出版时间：May 13, 2014
• 年：2014
• 卷：26
• 期：9
• 页码：2983-2990
• 全文大小：548K
• 年卷期：v.26,no.9(May 13, 2014)
• ISSN：1520-5002

文摘

Three diamine monomers (ethylenediamine, butylenediamine, and p-phenylenediamine) were selected for cross-linking graphene oxide (GO) to prepare composite graphene oxide-framework (GOF) membranes through filtration using a pressure-assisted self-assembly technique. The membranes were applied to separate an ethanol鈥搘ater mixture by pervaporation. Unmodified GO comprised only hydrogen bonds and 蟺鈥撓€ interactions, but after cross-linking it with a diamine, attenuated total reflectance鈥揊ourier transform infrared and X-ray photoelectron spectroscopy demonstrated that the diamine was chemically bonded both to GO and the membrane support. Moreover, GO hydrophilicity was substantially altered; water contact angle increased from 24.4掳 to 80.6掳 (from cross-linking with an aliphatic structure of diamine to cross-linking with an aromatic structure). Results of X-ray diffraction showed that d-spacing in GOF layers varied from 10.4 to 8.7 脜. For GOFs presoaked in 90 wt % ethanol鈥搘ater, covalent bonds between the layer and diamine could effectively suppress stretching of d-spacing. Cross-linking with ethylenediamine produced a composite membrane that exhibited a short interlayer d-spacing and delivered an excellent pervaporation performance at 80 掳C: permeation flux = 2297 g/(m² h); water concentration in permeate = 99.8 wt %. The membrane showed stability during a long-term operation at 30 掳C for 120 h.