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首页> 外文学位 >MIL-53 frameworks in mixed-matrix membranes and cross-linked ZIF-8/matrimidRTM mixed-matrix membranes for gas separation.
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MIL-53 frameworks in mixed-matrix membranes and cross-linked ZIF-8/matrimidRTM mixed-matrix membranes for gas separation.

机译：混合基质膜和交联的ZIF-8 / matrimidRTM混合基质膜中的MIL-53框架用于气体分离。

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摘要

Mixed matrix membranes (MMMs) are hybrid materials consisting of two phases: an inorganic nanoscale particle as the discrete phase, and a polymeric material as the continuous phase. The incorporation of inorganic particles into a polymer can improve a membrane's overall separation performance. MMMs incorporating metal-organic frameworks (MOFs) have exhibited promising gas separation performance. MOFs are inorganic-organic crystals constructed from metal ions that are linked by polydentate ligands. Zeolitic imidazolate frameworks (ZIFs) are a sub-class of MOFs that uses imidazole analogues as ligands. In these studies, the MOF MIL-53 and ZIF-8 were successfully synthesized and characterized by a battery of analytical techniques including XRD, FTIR, TGA, N2 adsorption, and SEM, and were incorporated into MMMs with Matrimid® polymer.;In chapter 1, MIL-53/Matrimid® MMMs containing MIL-53-ht (open-pore form) were fabricated, characterized and obtained permeability values higher than Matrimid®. Selectivities decreased for the gas pairs of O2/N2, H2/O2, H2/CO2, and H2/N2. However, slight enhancement of the CO2/CH4 selectivity was observed for the MIL-53-ht/Matrimid® compared to that of Matrimid ®. The MIL-53-as/Matrimid® MMM also showed an increase in permeability as well as an increase in selectivity for the gas pairs H2/O2, CO2/CH4, H 2/CH4, and H2/N2. The MIL-53-lt/Matrimid ® MMM showed that it does not retain its closed-pore form in the MMM due to chloroform solvent opening the pores and eventually polymer confinement of the MIL 53 framework in the MMM.;In chapter 2, easy synthesis and fabrication of the MIL-53 MOF membrane was realized using a seeded growth method with a commercially available alumina TLC plate. The MOF membrane had a well-intergrown and dense layer of MIL-53 crystals on the surface of the alumina substrate. The MIL-53 crystals were also converted to the MIL-53-lt (closed-pore form) after heating at 330 °C and cooling to room temperature, which confirms the breathing ability of the MOF.;In chapter 3, a comprehensive approach for membrane materials in order to achieve high productivity and separation efficiency was applied by incorporating additives into polymers and cross-linking the resulting MMM that could lead to increase and simultaneous selectivity enhancement. ZIF-8 was used as an additive in these MMMs. ZIF-8 can readily absorb small gases such, as H 2 and CO2 due to its 3.4 Å pore aperture. ZIF-8/Matrimid ® MMMs were fabricated with a spin-coated Matrimid® layer on one surface and cross-linked with EDA vapor. This membrane morphology could lead to enhanced selectivities due to the cross-linked layer, at the same time maintain the high permeability of the bulk MMM. The permeabilities decreased for the cross-linked, spin-coated Matrimid® ZIF-8/Matrimid ® MMMs. However, there was enhancement in selectivities for H 2/CO2, H2/N2, H2/O 2 and H2/CH4 gas pairs, which can be due to reduction of diffusive pathways for larger gas molecules. Compared to uncross-linked ZIF-8/Matrimid® MMMs, the cross-linked, spin-coated Matrimid ® ZIF-8/Matrimid® MMMs lie close to the Robeson's upper bound for H2/CO2 suggesting its potential for this gas pair separation.
机译：混合基质膜（MMM）是由两相组成的杂化材料：无机纳米级颗粒作为离散相，聚合材料作为连续相。将无机颗粒掺入聚合物中可以改善膜的整体分离性能。结合了金属有机骨架（MOF）的MMM表现出令人鼓舞的气体分离性能。 MOF是由通过多齿配体连接的金属离子构成的无机有机晶体。沸石咪唑酸盐骨架（ZIF）是使用咪唑类似物作为配体的MOF的子类。在这些研究中，通过一系列分析技术（包括XRD，FTIR，TGA，N2吸附和SEM）成功地合成了MOF MIL-53和ZIF-8，并与Matrimid®聚合物一起掺入了MMM中。参照图1，制造了包含MIL-53-ht（开孔形式）的MIL-53 /Matrimid®MMM，表征并获得了比Matrimid®高的磁导率值。 O2 / N2，H2 / O2，H2 / CO2和H2 / N2气体对的选择性降低。但是，与Matrimid®相比，MIL-53-ht /Matrimid®的CO2 / CH4选择性略有提高。 MIL-53-as /Matrimid®MMM还显示出对气体对H2 / O2，CO2 / CH4，H 2 / CH4和H2 / N2的渗透率以及选择性的增加。 MIL-53-lt / Matrimid®MMM表明，由于氯仿溶剂打开了孔，并最终将MIL 53骨架限制在MMM中，因此MMM不能保持其闭孔形式在MMM中。 MIL-53 MOF膜的合成和制造是使用种子生长法和市售氧化铝TLC板实现的。 MOF膜在氧化铝基材的表面上有一个密实共生的MIL-53晶体层。在330°C加热并冷却至室温后，MIL-53晶体也转换为MIL-53-lt（闭孔形式），这证实了MOF的呼吸能力。在第3章中，介绍了一种综合方法为了达到高生产率和分离效率的目的，通过在聚合物中掺入添加剂并使生成的MMM交联来实现膜材料的分离，从而提高选择性和选择性。 ZIF-8用作这些MMM中的添加剂。 ZIF-8的孔径为3.4Å，可以轻松吸收诸如H 2和CO2之类的小气体。 ZIF-8 /Matrimid®MMM的制造是在一个表面上具有旋涂的Matrimid®层，并与EDA蒸汽交联。由于交联层的存在，这种膜的形态可能导致选择性的提高，同时保持了本体MMM的高渗透性。交联的旋涂Matrimid®ZIF-8 /Matrimid®MMM的渗透率降低。但是，对H 2 / CO2，H2 / N2，H2 / O 2和H2 / CH4气体对的选择性有所提高，这可能是由于较大气体分子的扩散途径减少所致。与未交联的ZIF-8 /Matrimid®MMM相比，交联的旋涂Matrimid®ZIF-8 /Matrimid®MMM接近Robeson的H2 / CO2上限，表明其有可能用于这种气体对分离。

著录项

  • 作者

    Hsieh, Josephine Ordonez.;

  • 作者单位

    The University of Texas at Dallas.;

  • 授予单位 The University of Texas at Dallas.;
  • 学科 Chemistry General.;Chemistry Analytical.;Engineering Materials Science.
  • 学位 Ph.D.
  • 年度 2012
  • 页码 140 p.
  • 总页数 140
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 康复医学;
  • 关键词

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