Application And Synthesis Of Different Condensed Matter Zeolite Materials

Zeolite has been used in industrial production and real life widely because ofthetunable pore size, larger surface area (up to1500m2/g), acid and alkali resistant andother special physical and chemical characteristics. With the progress of science andtechnology, people greatly expand the application range of zeolites, from the initialseparation, catalysis and adsorption to the electronic components, optical materials,biological materials and other applications. In recent years the functionalized zeolite hasbeen used in other field. Zeolite membrane, spheres and block have been synthesized.Therefore our research work focused on the synthesis of different condensed matter zeolitematerials, and examine various factors of different zeolites in condensed matter dielectricmaterial moisture sensitive material and material direction of the chiral separationapplications.This paper describes an application of UV radiation near room temperature conditionsfor the removal of the template in the synthesis of micro/mesoporous materials, such asmesoporous MCM-41, Silicalite-1, zeolite LTA etc. The UV radiation relies on the exposureof the sample to short-wavelength ultraviolet(UV) radiation in air and the ozoneenvironment generated by a medium pressure mercury lamp(184-257nm). The structuresand organic contents of the micro/mesoporous materials before and after UV radiation weredetermined using a combination of XRD, FT-IR, BET, carbon analysis and SEM. XRDpatterns showed that the framework structure was kept after UV radiation or thermallycalcinations. Before and after calcination the sample made similar characterization forcomparison. FT-IR data showed the complete removal of the template in micro/mesoporousmaterials. But it is only useful for the complete removal of the template of mesoporousMCM-41and Silicalite-1nanoparticle, while there was a trace of residual template inzeolite LTA and zeolite Y nanoparticles. The SEM images showed micro/mesoporousnanoparticles UV treated have no obvious aggregation.The UV radiation is also efficient forthe complete removal of the template in the preparation of Silicalite-1thin film only after6h exposure time, while the thermally calcination process is more than3days. The SEMimages reveal the formation of a continuous thin film from displaying densely packedcrystals and there is not any significant cracks or pin holls. Compared with conventionalthermally calcination, the method provides an efficient and economical approach for thepreparation of high quality zeolite thin films free of template. Organic-functionalizedmesoporous silica films (Me-MCM-TEOS) have been produced using co-condensation ofmethyltrimethoxyslane and tetraethyl orthosilicate (TEOS), and a TEOS vapor treatmentbefore the removal of surfactant by spin-coating method. The materials have beencharacterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR)and Field emission scanning electron microscope (FE-SEM). Dielectric constant k isdetermined using Ellipsometer, and elastic modulus (Young’s modulus, E) and hardness ofthe films are measured by a Nano Indenter XP. XRD patterns and FT-IR spectra show that the methylsilated mesoporous films (Me-MCM-TEOS-CAL) have densified mesochannelwalls and an increased hydrophobic property by the TEOS vapor treatment. The k value isas low as1.78even in80%-relative-humidity environments for seven days. Mechanicalstrength is also high enough to withstand the stresses that occur during the chemicalmechanical polishing (CMP) and wire bonding process (E>6.0GPa). TEOS vapor treatedmesoporous silica films without the addition of methyl groups (MCM-TEOS) are alsosynthesized for a comparison.Mesoporous silica SBA-15was prepared through a hydrothermal treatment in acidmedia. The as-synthesized samples show the uniform pore size and long-distance orderedarrangement of hexagonal structure, which is typically ordered mesoporous structure.Through the optimal experiments, SBA-15products with uniform morphology of hexagonallamelliform were obtained. The biggest pore size is mainly centered on12.7nm. Theas-made SBA-15possesses of good thermal stability. The mesoporous silica SBA-15wasdeposited on the quartz crystal micro-balances (QCMs) to construct highly stable andsensitive humidity sensors. The humidity sensing characteristics of the sensors wereinvestigated by measuring the resonant frequency shift of QCMs due to the additional massloading caused by adsorption of water. The results showed that the sensors had highsensitivity, good stability, short response/recovery time, well reproducibility and narrowhysteresis.Improved humidity sensors based on quartz crystal micro-balance coated withmesoporous silica MCM-41thin film were fabricated. XRD, BET, TEM and SEM wereemployed to characterize sensing films so as to study the effects of its pore structure on thehumidity sensing properties. The results reveal that sensitivity over a wide humidity rangeand especially for low humidity conditions. The high sensitivity, well reproducibility, shortresponse and recovery times obtained were ascribed to the ordered pore arrays and highsurface area of the MCM-41films. This study has significance in tailoring the moisturesensitivity in the design of diverse sensors for practical applications. Herein, not only anovel and low-cost humidity sensor material was exploited, but also a new application areafor mesoporous materials was opened up.Molecularly imprinted composite materials (MICMs) selectiveto S-naproxen wereprepared onthe surface of mesoporous silica sphere (SBA-15) by a surface imprintingtechnique with S-naproxenas the template and42vinylpyridine as the functional monomer.As observed by SEMandpore structure analysis, the microspheres coated with thesynthesized molecularlyimprintedpolymers have a uniform particle size, narrowsizedistributionandhighspecific surfacearea. The polymer layer on SBA-15can be determinedby SEM, XRD and FT-IR spectroscopy. Scatchard analysis shows that two kinds ofrecognition sites are formed on the MICMS with the apparent binding capacities of2.504μmol/g and16.680mol/g, respectively. Based on anisothermalbindingthermodynamicinvestigation, the absorption to template is found to be spontaneous.