Preparation And Separation Application Of Membranes Based On Metal-Organic Frameworks

As a novel type of ordered porous material,metal-organic frameworks(MOFs)have shown great potential in the field of membrane separation due to their tunable pore size and modifiable surface,whether in gas separation or liquid separation.In this thesis,membrane materials based on MOFs were prepared by different methods.Then a series of characterization of these materials were carried out(SEM,TEM,AFM,X-ray powder diffraction,X-ray photoelectron energy spectrum,thermogravimetric analysis,FTIR analysis,etc.).Furthermore,the gas separation,alcohol-water separation,and oil-water separation performance of these membrane materials were evaluated.The main research contents are described as follows:1.The Co(OH)2 NS@GO MMMs filtrated by physical mixing solution result in continuous membranes on a nylon support.Then this membrane was transformed to ZIF-67@GO by in situ reaction with 2-methylimidazole(2-MIM)ligands under the confinement effect of GO.H2/CO2 separation test was performed on the prepared membrane materials.The results show that the materials possess better separation effect on H2/CO2.2.The flexible two-dimensional HKUST-1@GO MMMs was prepared by layer-by-layer filtration and in-situ transformation.After a series of performance characterization,its performance of H2/CO2 separation was tested.The test results show that the materials possess good separation performance on H2/CO2.3.The surface wettability switching of JUC-150 Metal-Organic Framework(MOF)mesh from hydrophilicity to hydrophobicity was achieved by a facial polydimethylsiloxane(PDMS)modification method.Subsequently,the oil-water separation test was carried out.The PDMS modified JUC-150 mesh(JUC-150@PDMS mesh)exhibited high oil-water separation efficiency and good cycling stability.4.The hydrophilic Ni2(L-asp)2bipy membrane is switched to hydrophobic Ni2(L-asp)2bipy@PDMS membrane via vapor deposition of PDMS.Then the pervaporation studies based on the both two membranes provide insight into the effect of surface wettability on the bio-ethanol purification performance.