The Synthesis Of Different Morphology Porous Materials And The Encapsulation Of Optical Functional Materials

Recently, the research of molecular sieves and porous materials are focus not only on adsorption, separation, ion-exchange and catalysis, but also on the preparation and development of the host materials for optical or optoelectronic molecules. however, the application of such functional materials, especially micro-devices, are based on handful morphology, higher quality membrane, and lager size of zeolites crystals, which are very different to achieve. In our research work, narrowlined emission spectrum of the MB/MFI composite was demonstrated. By physical vapor deposition (PVD) method, p-nitro aniline (PNA) was encapsulated in the pores of high-oriented silicalite-1 film, and fluorescence of the PNA/silicalite-1 film was observed. Laser dye coumarin derivative has been successfully incorporated into mesoporous powder, fiber, and film by one-pot method. The channels of mesoporous silica can be modified with organic functional groups and post-grafted organic dyes. Through electrospining technique, the mesoporous fibers which doped with coumarin 151 are obtained. High-quality MFI large single crystals can be used as host material which were synthesized using monocrystallion silicon slice as silicon source, and methylene blue (MB) are used as guest molecular. Narrow linewidth action was achieved in the MB/MFI composite which obtained by physical vapor deposition (PVD). The emission spectrum final luminescence spectrum full width at half-maximum is about 2nm. High oriented siicalite-1 film was prepared by in situ crystallization onto MSS support. The MSS with (111) was most suitable for the preparation of silicalite-1 film, and it was shown from XRD patterns that the crystallographic b-axis of MFI crystals was perpendicular to the MSS surface. The experimental results also got theoretical support from molecular mechanics, according to the structure of MSS surface and silicalite-1 framework. PNA encapsulated silicalite-1 film composites were prepared by PVD. The results of UV and XPS showed that the PNA molecule were encapsulated into the channels of the silicalite-1 zeolite on film, and the composite showed strong fluorescence under 488nm laser. For many applications, the mesoporous materials should be controlled not only on the nanometer scale of the pore structure but also on the micrometer scale of the morphology. A diversity of mesoporous silica with defined morphology, like films, spheres, fibers or tubules, can be used as good host material. Dye molecule –coumarin 151 has been successfully incorporated into mesoporous powder, fiber, and film by one-pot methods. In the preparation process, add organic chromophores to the synthesis mixtures, the template was supermolecule which formed by interaction between structure-directing agent and dye molecules. This procedure results in a uniform dispersion of the dyes in the mesoporous host, and keep the well-ordered porous properties. In UV and PL spectra, significant blue shift can be observed. The difference that exist in the UV and PL bands implied that the nearest-neighbor structure around dye molecules was not so simple as the cluster structure of solvate in the solution if compared with solvents. The polarity of the local environment surrounding the dye molecules has been changed because of interaction between dye molecules and structure-directing agent through the inter-molecular force such as electrostatic force and van der waals force. The wall surface of mesoporous silica can be modified with proper organicfunctional groups and provide accessibility for anchoring other substrates. The encapsulation of guest molecules in these hosts leads to composite materials with novel properties, which enable possible applications as materials for catalysis, adsorption, and electronic devices. Firstly, the template of the msoporous material must be removed. There are three method: calcination, extraction, and microwave digestion. Microwave digestion can fast and completely remove the template and can keep rich surface silanol groups. Rhodamine B and coumarin 4 have been encapsulated in the channels of rodlike SBA-15 with NH2 group. The composite of Rh B/Rsba-15 can be observed blue shift in UV and PL spectra because of the dye mono-disperse in the channels of SBA-15. But red-shift can be observed in the Coumarin 4/Rsba-15 composite, when pumped with 355nm laser, there are wide fluorescence band at lower intensity, increasing the laser intensity, narrowed emission band can be showed. The line structure of laser emission spectrum is determined by the cavity geometry, since the cavity permits only certain fields or eigen modes to oscillate. It is possible to calculate the wavelength spacing of the modes using the formula ?λ≈λ2 ?2nL, assuming a Fabry-Perot geometry for the laser cavity. The match between the calculated mode separation and the measured one is satisfactory. The smaller length of the composite can obtain wider output lasing mode. Among generating 1D nanostructures methods, electrospinning seems to provide the simplest approach to nanofibers with both solid and hollow interiors. When a high voltage is applied, the pendent drop of polymer solution at the nozzle of the spinneret will become highly electrified. The electrified jet undergoes a stretching and whipping process, leading to the formation of a long and thin thread. As the liquid jet is continuously elongated and the solvent is evaporated, its diameter can be greatly reduced to nanometers. Through this method, the nanofibers can be obtained which have mesosporous structure and doped with coumarin 151. Lasing from the electrospinning nanofibers can be observed, when the mesoporous structure fibers iiiwere pumped by the third harmonic light of a Q-switched Nd:YAG laser (355nm, ~5ns pulse width, 10Hz). Coumarin dyes are considered to form a different class of compounds able to give ion-radical pair (ICT formation) or twisted intramolecular charge transfer (TICT) excited states with highly specific solute-solvent interaction. In the preparative process, there are not only polar solvent-EtOH but also HCl in the sample solution. Under laser intense fast pulse excitation, the number density of the excited molecules existing in the TICT conformation could become quite large and serve to produce high gain which could then lead to superradiance from the TICT conformation. The dye molecules are sited into the channels of mseoporous fibers which can be used as microresonator, and the laser emission spectra are determined by cavity geometry.