In the beginning of the 1960s it was found that films, which were prepared by dispersingnoble metals (such as silver, gold, and so on) onto an insulative substrate, had the electricproperties like sedriconducive mater...In the beginning of the 1960s it was found that films, which were prepared by dispersingnoble metals (such as silver, gold, and so on) onto an insulative substrate, had the electricproperties like sedriconducive materials. These films were found to be sensitive to somegases in environment, and used to detect the existenee of those gases by P. Mazzetti andhis coworkers. Thus they could be used as a special kind of gas sensing materials.展开更多
Monolithic TiO 2 aerogels have been prepared from titanium n butoxide by sol gel process and supercritical drying technique, and the structural properties of the aerogel samples have been characterized by means of SEM...Monolithic TiO 2 aerogels have been prepared from titanium n butoxide by sol gel process and supercritical drying technique, and the structural properties of the aerogel samples have been characterized by means of SEM, TEM, XRD, IR, BET and pore distribution analysis. The results indicated that the optimum condition for preparing monolithic TiO 2 aerogels was n [Ti(OC 4H 9) 4]∶ n (C 2H 5OH)∶ n (H 2O)∶ n (HNO 3) =1∶18.3∶3.75∶0.14. The final aerogels which consist of colloidal particles with diameters of about 5 nm were found to be with coherent uniform size and low density solid inorganic materials with porosity of about 90%, and contained mesopore in the range of 10-20 nm. The monolithic TiO 2 aerogels were of the pure amorphous form at room temperature, which would be converted into anatase and then into rutile by increasing the temperature of heat treatment.展开更多
文摘In the beginning of the 1960s it was found that films, which were prepared by dispersingnoble metals (such as silver, gold, and so on) onto an insulative substrate, had the electricproperties like sedriconducive materials. These films were found to be sensitive to somegases in environment, and used to detect the existenee of those gases by P. Mazzetti andhis coworkers. Thus they could be used as a special kind of gas sensing materials.
文摘Monolithic TiO 2 aerogels have been prepared from titanium n butoxide by sol gel process and supercritical drying technique, and the structural properties of the aerogel samples have been characterized by means of SEM, TEM, XRD, IR, BET and pore distribution analysis. The results indicated that the optimum condition for preparing monolithic TiO 2 aerogels was n [Ti(OC 4H 9) 4]∶ n (C 2H 5OH)∶ n (H 2O)∶ n (HNO 3) =1∶18.3∶3.75∶0.14. The final aerogels which consist of colloidal particles with diameters of about 5 nm were found to be with coherent uniform size and low density solid inorganic materials with porosity of about 90%, and contained mesopore in the range of 10-20 nm. The monolithic TiO 2 aerogels were of the pure amorphous form at room temperature, which would be converted into anatase and then into rutile by increasing the temperature of heat treatment.
