Control Synthesis Of Transparent Mesoporous Alumina Gel Monoliths

Transparent mesoporous alumina gel monolith has real potential as optical substrate material in new material of optical, electrical and magnetic field for its easy cutting of macro appearence, excellent transparency, full of internal mesostructured channel and charge performance of framework, especially for guest molecules can be dispersed efficiently in the present of template. What’s more, the obtained mesoporous alumina after removing template also can be used in traditional adsorption, separation, drug controlled release and catalysis area. Obviously, the bi-functional application make the preparation of transparent mesoporous alumina possessing a significant research value. Unfortunately, because of the complexity processes of hydrolyzation, condensation of organic and inorganic aluminum salts, uncontrollable reaction speed and the strong surface tension during drying of wet gel make the transparent alumina material was limited in power and film.Based on the facts above, our works take experience of predecessors’ theories of preparing traditional alumina gel monoliths and mesoporous alumina power and film materials, by the comprehensive exploring in different system of preparing alumina gel in the present of template, we first synthesis the transparent mesoporous alumina gel monolith material successfully. Then we make a preliminary study of material’s structure and optical property. The major works and results are as follows:1、Based on Yoldas’ s traditional alumina gel preparation system, our work systematically study the influence of parameters and synthetic conditions on obtained xerogel’s transparency and integrity in the process of hydrolyzation-precipitation-peptization-gelation by using organic and inorganic aluminum salts. The results show that the transparent alumina-template composite xerogel material can not be got whether adding the template or not, what’s worse, the large amount using of water and strong capillary tension make the integrity of xerogel hard to control.2、On the basis of Sinkó’s thought of aluminum nitrate,n-propanol hydrolyzation to synthesis alumina gel under reflux condition, we also can not get the transparent, integrated mesoporous alumina xerogel, even so by introducing template in different stages to realize sol-gel and systematical controlling of the parameters and component ratio on drying stage.3、Learning Gash’s experience of using propylene epoxide as gelation promoter to synthesis alumina aerogel, the control synthesis of transparent mesoporous alumina xerogel was first realized with cationic quaternary ammonium salt surfactants(CnH2n+1N(CH3)3,n=12,14,16,18)and nonionic block copolymer F127 as template respectively under different temperature condition by adjusting the component ratio and controlling the process of sol-gel. Then we use different characterization methods involves X-ray diffraction(XRD), N2 adsorption, thermal gravimetric(TG) analysis, FT-IR, Transmission electron microscopy(TEM) and Fluorescence spectra to study material’s structure preliminary, the laser dye Rh6 G was also doped into transparent mesoporous alumina monolith to study the material’ optical properties. The results display that the proposed transparent mesoporous alumina gel monolith in the work can be control synthesized in a wide component ratio, and the molar ratio of Rh6G/Al2O3 regulated between 1×10-2 and 1×10-5 can not form dimerization phenomenon obviously. The material can be a excellent optical substrate material.