Synthesis And Application Of Metal-organic Framework Membrane

Metal-organic framework materials (referred as MOFs) have decades ofdevelopment history, but they are the research hot in the major domestic andinternational research groups and each year there are new MOFs or MOFs membranematerials published in succession. MOFs consist of metal ions or metal clusters andorganic ligands by coordination bond which can show a variety of different topologystructure due to its composition metal ions (or metal clusters) or organic ligands. Themetal organic framework material membranes are used for separation of smallmolecules (gas, liquid, etc.), catalytic reactions, electromagnetic and optical storagegas, etc for pore size adjustable, high surface area. From the actual needing, in thispaper we have designed and synthesized various MOFs membrane materials, and withone of MOFs membranes as template successfully prepared the microporous,electrical activity polyaniline by the MOFs membrane template-removing method forthe first time.Whether a gas or liquid separation, separation MOFs membrane must has goodcontinuity and compactness, also call a mold, which requires the MOFs material has aconsiderable thermal stability, chemical stability and good film-forming propertiesand so on. Therefore, we have chosen metal-organic framework materials HKUST-1for the study for its chemical stability and thermal stability are both very good.HKUST-1has been repeatedly studied by domestic and foreign research groups sincethe advent of the material, which was also the choice forming one of the largest ofMOFs on the different film substrates, based on this consideration, in order to reflectthe novelty of the film substrate, we prepared HKUST-1membrane by hydrothermalsynthesis on the surface of the acidification of poly (methyl methacrylate)(PMMA-PMAA). Because PMMA can be coated on various substrates, we canprepare MOFs membrane on various substrates coated PMMA-PMAA. The goodnews was that we not only obtained the continuous and dense HKUST-1MOFsmembrane by this method but also got a large area of freestanding HKUST-1membrane by simply removing the substrate. We also explored the separation performance of PMMA-PMAA/SSN supported HKUST-1membrane at differenttemperatures to component H2/CO2, H2/N2, H2/CH4, the results showed that thisMOFs membrane was a very good choose in the recycling of hydrogen, and highestseparation factor at room temperature were9.24,8.91,11.20(Chapter II).In order to get high-quality MOFs membrane, selecting an appropriate MOF ison the one hand, the other hand is to choose a suitable substrate, and numerousexperiments show that substrates show a crucial role in the preparation process ofMOFs membrane. Therefore, we have shifted attention to the polyaniline (PANI)which is well known easily filmed in the case of heating, and can be coated on varioussubstrates, such as glass, ceramic, metal and so on after successfully preparingPMMA-PMAA supported HKUST-1membrane, and it has a nature of conductivitywhich PMMA doesn′t have. We can find some new uses by the conductivityproperties of PANI substrate. Fortunately, by this method we not only preparedHKUST-1membrane, but also successfully prepared MIL-68(In) andZn2BDC2DABCO MOFs membranes. In order to study the compactness andcontinuity of membranes, we studied the gas separation performance ofSSN-PANI-HKUST-1MOFs membrane about H2/CO2, H2/N2, H2/CH4. The resultswere not good as the PMMA-PMAA/SSN supported HKUST-1membrane but alsohad been among the highest reported (Chapter III).Polyaniline and polypyrrole (Polyaniline, PANI; Polypyrrole, PPy) are the mostpractical conductive polymer materials for simple synthesis and good stability. So far,preparation methods of polyaniline and polypyrrole which have been reported includechemical method, interfacial polymerization, template method and electrochemicalmethods. Here we prepared black polyaniline and polypyrrole with HKUST-1membrane as a template by a MOFs membrane template-removing method which hadnever been used. The as-prepared samples were characterized by XRD, SEM, TEM,13C CP/MAS NMR, EDS, FTIR, N2adsorption characterization analysis, and fromthe pore distribution of polyaniline we found that the pore size of0.84nm, N2adsorption curve is typical of the type Ⅰadsorption isotherm structure, which meanswe obtain the microporous polyaniline by this method. We also carried out the electrochemical aspects of the test of microporous material polyaniline and found thatit had a very good cyclic voltammetry in potassium chloride solution, conductivitytest results0.125S/cm which ranged between conductors and semiconductors(Chapter IV).