物理化学学报 >> 2011, Vol. 27 >> Issue (01): 241-247.doi: 10.3866/PKU.WHXB20110119

材料物理化学 上一篇    下一篇

有机功能化α-Al2O3陶瓷中空纤维表面合成高性能分离氢用NaA分子筛膜

陈华荣1, 常然然1, 李莉2, 袁文辉1   

  1. 1. 华南理工大学化学与化工学院, 广州 510640;
    2. 华南理工大学环境科学与工程学院, 广州 510640
  • 收稿日期:2010-09-08 修回日期:2010-09-30 发布日期:2010-12-31
  • 通讯作者: 袁文辉 E-mail:cewhyuan@scut.edu.cn
  • 基金资助:

    国家自然科学基金(20976057)资助项目

High Performance NaA Zeolite Membrane for Hydrogen Separation Synthesized on an Organic-Functionalized α-Al2O3 Ceramic Hollow Fiber Surface

CHEN Hua-Rong1, CHANG Ran-Ran1, LI Li2, YUAN Wen-Hui1   

  1. 1. School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou 510640, P. R. China;
    2. College of Environmental Science and Engineering, South China University of Technology, Guangzhou 510640, P. R. China
  • Received:2010-09-08 Revised:2010-09-30 Published:2010-12-31
  • Contact: YUAN Wen-Hui E-mail:cewhyuan@scut.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (20976057).

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摘要：

通过浸渍3-氨丙基甲基二乙氧基硅烷(ADMS)对α-Al2O3中空纤维载体进行有机功能化改性, 使载体表面带正电, 利用NaA分子筛晶种负电性与功能化载体之间的静电吸附机理进行预涂晶种, 采用微波加热-二次生长法于载体表面合成了NaA分子筛膜. 采用X射线衍射(XRD)、zeta 电位、扫描电子显微镜(SEM)等分析手段和气体渗透实验对NaA分子筛膜进行了表征. 考察了未改性NaA分子筛膜与改性NaA分子筛膜的形貌、结构和气体渗透性能差异. XRD结果表明载体表面只有NaA分子筛生成; zeta 电位分析表明NaA分子筛晶种及分子筛前驱体与有机功能化载体电位相反, 存在静电吸附作用; SEM结果显示改性NaA分子筛膜表面颗粒相互联结呈孪生态, 膜厚约5 μm, 膜层致密、均匀、平整; 在不同温度下对H2、O2、N2和C3H8进行气体渗透测试,35 °C条件下改性NaA分子筛膜对H2的渗透率仅为3.6×10-7 mol·m-2·s-1·Pa-1, 较未改性NaA分子筛膜的渗透率(4.0×10-7 mol·m-2·s-1·Pa-1)低, 而改性NaA分子筛膜的H2/C3H8理想分离系数则高达11.25, 远大于未改性NaA分子筛膜的H2/C3H8理想分离系数(5.06).

关键词: 中空纤维, 有机功能化, NaA分子筛膜, 微波加热, 氢气分离

Abstract:

Positively charged organic-functionalized α-Al2O3 ceramic hollow fiber was obtained by dip-coating the substrate with a 3-aminopropyl-(diethoxy)methylsilane (ADMS) solution. Negatively charged NaA zeolite particles were deposited on the substrate surface and used as seed for further secondary growth by the electrostatic adsorption of a positively charged organic-functionalized substrate and NaA zeolite particles. The NaA zeolite membrane was synthesized on a porous α-Al2O3 ceramic hollow fiber support by the microwave heating-secondary growth method. The as-synthesized NaA zeolite membranes were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), zeta potential, and gas permeation tests. The differences in morphology, structure, and gas permeability between the NaA zeolite and the ADMS-modified substrate supported NaA zeolite membrane were determined. XRD results show that only NaA zeolite is present on the support. The zeta potential results indicate that opposite charges exist between the NaA zeolite seed or precursor and the organic-functionalized substrate surface, which confirms the electrostatic adsorption between them. SEM images show that a smooth and dense membrane (5 μm thick) is obtained and the particles are twinborn by good intergrowth on the ADMS-modified substrate supported NaA zeolite membrane surface. Gas permeation tests with H2, O2, N2, and C3H8 at different temperatures show that the permeability of H2 on the ADMS-modified substrate supported NaA zeolite membrane at 35 °C is 3.6×10-7 mol·m-2·s-1·Pa-1, which is lower than that (4.0×10-7 mol·m-2·s-1·Pa-1) of the NaA zeolite membrane. The ideal permselectivity of H2/C3H8 is 11.25, which is far higher than that (5.06) of the NaA zeolite membrane.

Key words: Hollow fiber, Organic-functionalization, NaA zeolite membrane, Microwave heating, Hydrogen separation