The MCM-48Molecular Sieve Mesoporous Materials And Membrane Preparation

MCM-48materials attributable to the Ia3d crystal system, has a specialthree-dimensional cubic pore structure, so that the transmisstion and proliferation of thematerial has a great advantage.MCM-48not only has a good transmission performance, andalso has good chemical stability, high mechanical strength, not easy to swelling, a largesurface area and pore uniformity adjustable advantages.MCM-48preparation condition isharsh, is not easy to synthesis, and greatly limits in its practical application. Mesoporousmolecular sieve membrane reaction and separation of integration can be achieved if thequality of preparation and synthesis process of MCM-48film is expected to improve theconversion rate of reaction and reaction processes. Great prospect for the MCM-48membranehas been the focus of the reachers.At present, prepared on the porous carrier MCM-48membrane technology is not perfect. Therefore, MCM-48membrane still has a lot of space toresearch.Preparaion of this thesis of MCM-48powers and MCM-48membrane explores thedifferent methods of preparation of MCM-48powers and MCM-48membrane, analyze byX-ray powder diffraction （XRD）, scanning electron microscope （SEM） and hydrothermalstability, the conclusion is as follows:（1） A single-template （CTAB） method, by adding inorganic salts （NaF）, andmixed-template （P123and CTAB） are successfully prepared of MCM-48powers whichprovides a good foundation for the preparation of MCM-48membrane.Hydrothermal stability test for a single template method and by adding inorganic salt method,XRD results show that the inorganic salts adds to make the zeolite is heated in oilbath boiling12h and channel is not completely collapse, the inorganic salt to join an increaseof MCM-48hydrothermal stability. Prepared by mixing template agent（CTAB and P123） witha regular morphology of uniform size of MCM-48, for adding non-ionic surface active agent,weaken the force of the interface assemably to achieve the morphology control of zeolite. Thezeolite particles can be seen from SEM2μm and size uniformity.（2） Using APTES and TEOS as silica source, initiatively investigate both materialson the sample structure. APTES for5%and10%of the silicon source content can be thesynthesis of ordered mesoporous materials MCM-41.（3） Adding inorganic salt （NaF） synthesis of molecular sieve configurationsynthetic fluid, three-situ hydrothermal synthesis, successful preparation MCM-48membrane.For comparion the addition of inorganic salt on the membrane of the syntheticimpacts, with a single template method for configuration synthesis of liquid, in a carrier tube three in situ hydrothermal synthesis. It can be seen though SEM images of membrane surfaceby the molecular sieve particales deposite by the thickness of the membrane cross-section of4-6μm.When the drop is0.1Mpa, H₂/N₂separation factor is about2.61though MCM-48membrane.（4） The preparation of different concentrations of silica sol solution, and choice of20%silica sol solution to the impregnation, treatment of aluminum oxide carrier pipe at200℃for2h to make the carrier pipe connected tightly. MCM-48membrane is prepared by twohydrothermal synthesis successes. Be seen though the SEM images, the films surface issmooth continuous and the film thickness is4-6μm. When the drop is0.1Mpa,H₂/N₂separation factor is about2.41though MCM-48membrane.（5） Uniform size of MCM-48seeds, by simple methods successful overcome theagglomeration of the mesoporous molecular sieves, crystal coat by hot dipping method toprepare the seed layer. Secondary growth method on the basis of the seed layer, after twohydrothermal synthesis, the successful preparation of MCM-48membrane.Seen by SEMphotes, continuous smooth film surface, the film thickness obout6μm. When the drop is0.1Mpa, H₂/N₂separation factor is about2.71though MCM-48membrane.（6） For the first time the anti-diffusion method used in the preparation of mesoporousMCM-48membrane. Seed layer preparation with lower template and more water. Andpromote the heterogenous nucleation on the solid/liquid interface, after a synthesispreparation of MCM-48membrane.It can be seen by SEM that continuous film growth andfilm thickness about4μm. When the drop is0.1Mpa, H₂/N₂separation factor is about3.0though MCM-48membrane.