• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文学位 >Synthesis and characterization of mixed matrix membranes for gas separation.
【24h】

Synthesis and characterization of mixed matrix membranes for gas separation.

机译：用于气体分离的混合基质膜的合成与表征。

获取原文
获取原文并翻译 | 示例
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Mixed-matrix membranes were prepared from Matrimid RTM and mesoporous ZSM-5 nanoparticles containing crystalline ZSM-5. The mesoporous ZSM-5 has both micropores (0.54 nm) and mesopores (2.7 nm), which were confirmed by XRD, nitrogen adsorption, and TEM. The Young's moduli and glass transition temperatures of mixed-matrix membranes are higher than those of pure MatrimidRTM membranes, suggesting that the polymer chains may penetrate into the mesopores. The ideal selectivity for H2/N2 separation increased from 79.6 for pure Matrimid RTM to 143 at 10% loading, while the selectivity of O2/N 2 increased from 6.6 for pure MatrimidRTM to 10.4 at 20% loading. The ideal H2/CH4 separation factor increased from 83.3 to 169 at 20% loading. The results suggest that the mesopores of the ZSM-5 material can provide good interfacial contact between the nanoparticles and the polymer, since the polymer chains can penetrate into the mesopores. The micropores of ZSM-5 crystals can provide size and shape selectivity.; A carbon aerogel was prepared by carbonizing a resorcinol-formaldehyde polymer gel at 800°C. Nitrogen adsorption shows the obtained carbon aerogel has both micropores (0.54 nm) and mesopores (2.14 nm). Zeolite A and zeolite Y nanocrystals were grown in the mesopores of the carbon aerogel, resulting in carbon aerogel-zeolite composites. TEM confirmed the existence of nanosize zeolite crystals in the carbon aerogel matrix. Higher selectivity for the CO2/CH4, O2/N2 and H2/N 2 separation were obtained for carbon aerogel-zeolite, carbon aerogel-zeolite-Matrimid RTM membranes. The small pore diameter of zeolite A and the affinity between the CO2 and zeolite crystals make it perfect for CO 2/CH4 separation.; Short single-walled carbon nanotubes (SWNT) functionalized with carboxylic acid groups were made and incorporated into MatrimidRTM to form mixed-matrix membranes. SEM images of mixed-matrix membranes cross-sections showed good dispersion and interfacial contact. Pure gas permeation showed 100% increase in permeability compared with pure MatrimidRTM, while the ideal selectivity of O2/N2, CO2/CH 4 and H2/N2 remained unchanged. The higher permeability can be attributed to the higher diffusivity in the SWNT.; A microporous metal organic framework Cu-4,4'-bipyridine-hexafluorosilicate (Cu-BPY-HFS), having a surface area of 2000 m2/g, was combined with MatrimidRTM polymer to form free standing films. The ideal selectivity of CH4/N2 increased from 0.95 to 1.21. This result suggests the Cu-BPY-HFS has a strong affinity towards CH 4 and favors the permeation of CH4. For CH4/N 2 gas mixtures, the selectivity increased from 0.95 to 1.7. The Cu-BPY-HFS's affinity towards CH4 and its large surface area increased the solubility of CH4 in the mixed-matrix membranes which led to higher selectivity towards CH4.; PMOs with different organic frameworks were prepared and incorporated into MatrimidRTM to form mixed-matrix membranes. Good interfacial contact was obtained because of the hydrophobic frameworks and mesopores. The permeabilities of all gases exhibit a substantial increase due to the fast diffusion in mesopores. The ideal selectivity for H2/N 2 and O2/N2 separation showed little change. There is no apparent difference when using PMOs with different organic frameworks. However, the CO2/CH4 ideal selectivity increased from 35 (pure MatrimidRTM) to 58 (10% MBS), then decreased to 40.; Matrimid membranes containing the Ag+-PMO (with ethenylene-bridged functional groups) complex were prepared. The Ag+ can bind pi-electrons from the C=C double bond of the ethenylene silica. The shift of C=C suggests interaction between the Ag+ and C=C pi-electrons, which helps to fix the Ag+ in the mesopores of the PMO. SEM images suggest good interfacial contact between the Ag+-PMO complex and the polymer. The propane/propylene mixture separation showed a 200% increase in selectivity, which is much lower than literature. The low selectivity can be attributed to the
机译：由Matrimid RTM和含有结晶ZSM-5的中孔ZSM-5纳米颗粒制备混合基质膜。 ZSM-5介孔同时具有微孔（0.54 nm）和中孔（2.7 nm），这已通过XRD，氮吸附和TEM证实。混合基质膜的杨氏模量和玻璃化转变温度高于纯MatrimidRTM膜的杨氏模量和玻璃化温度，表明聚合物链可能会渗透到中孔中。 H2 / N2分离的理想选择性从纯MatrimidRTM的79.6增加到10％负载下的143，而O2 / N 2的选择性从纯MatrimidRTM的6.6增加到20％负载下的10.4。在20％的负载下，理想的H2 / CH4分离系数从83.3增加到169。结果表明，ZSM-5材料的中孔可以在纳米粒子和聚合物之间提供良好的界面接触，因为聚合物链可以渗透到中孔中。 ZSM-5晶体的微孔可以提供尺寸和形状选择性。通过在800℃下碳化间苯二酚-甲醛聚合物凝胶来制备碳气凝胶。氮吸附表明，所获得的碳气凝胶同时具有微孔（0.54 nm）和中孔（2.14 nm）。沸石A和沸石Y纳米晶体在碳气凝胶的中孔中生长，得到碳气凝胶-沸石复合材料。 TEM证实了碳气凝胶基质中存在纳米沸石晶体。对于碳气凝胶-沸石，碳气凝胶-沸石-Matrimid RTM膜，获得了更高的CO2 / CH4，O2 / N2和H2 / N 2分离选择性。沸石A的小孔径以及CO2和沸石晶体之间的亲和力使其非常适合于CO 2 / CH4的分离。制备了用羧酸基团官能化的短单壁碳纳米管（SWNT），将其掺入MatrimidRTM中以形成混合基质膜。混合基质膜横截面的SEM图像显示出良好的分散性和界面接触。与纯MatrimidRTM相比，纯气体渗透率显示出100％的渗透率增加，而O2 / N2，CO2 / CH 4和H2 / N2的理想选择性保持不变。较高的渗透性可以归因于SWNT中较高的扩散率。将具有2000 m2 / g表面积的微孔金属有机骨架Cu-4,4'-联吡啶-六氟硅酸盐（Cu-BPY-HFS）与MatrimidRTM聚合物结合形成自立膜。 CH4 / N2的理想选择性从0.95增加到1.21。该结果表明Cu-BPY-HFS对CH 4具有很强的亲和力，并有利于CH 4的渗透。对于CH4 / N 2气体混合物，选择性从0.95增加到1.7。 Cu-BPY-HFS对CH4的亲和力和较大的表面积增加了CH4在混合基质膜中的溶解度，从而提高了对CH4的选择性。制备了具有不同有机骨架的PMO，并将其掺入MatrimidRTM中以形成混合基质膜。由于疏水骨架和中孔，获得了良好的界面接触。由于在中孔中的快速扩散，所有气体的渗透率都显示出明显的增加。 H2 / N 2和O2 / N2分离的理想选择性几乎没有变化。将PMO与不同的有机框架一起使用时，没有明显的区别。但是，CO2 / CH4理想选择性从35（纯MatrimidRTM）增加到58（10％MBS），然后降低到40。制备了含有Ag + -PMO（带有亚乙烯基桥连的官能团）复合物的Matrimid膜。 Ag +可以从亚乙烯基二氧化硅的C = C双键结合π电子。 C = C的移位表明Ag +和C = Cπ电子之间的相互作用，这有助于将Ag +固定在PMO的中孔中。 SEM图像表明Ag + -PMO配合物与聚合物之间的良好界面接触。丙烷/丙烯混合物的分离显示出200％的选择性增加，这远低于文献报道。选择性低可归因于

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号