Surface tension of sodium aluminate solution and the contact angle between Al（OH）3 particles and aluminate solution were measured, then the dependence of Al（OH）3 solubility on its particle size was calculated and ...Surface tension of sodium aluminate solution and the contact angle between Al（OH）3 particles and aluminate solution were measured, then the dependence of Al（OH）3 solubility on its particle size was calculated and thus the variation of the critical nucleus sizes was determined based on the Ostwald ripening formula. The results show that the Al（OH）3 solubility in sodium aluminate solution decreases with the increment of particle size, and the critical nucleus sizes increase with the rise of alkali concentration, caustic ratio and precipitation temperature. The results also imply that the presence of small particles in seeded precipitation system is an important factor to limit the depth of precipitation.展开更多
The phase and morphology transformation during the hydrothermal treating process of Y2O3 was evaluated with X-ray difference (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), particle ...The phase and morphology transformation during the hydrothermal treating process of Y2O3 was evaluated with X-ray difference (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), particle size and specific surface area determination. The results showed that the cubic Y2O3 did not transfer into hexagonal Y(OH)3 in pure water. Therefore, pure hexagonal Y(OH)3 with nanotube and microrod morphologies were obtained by hydrothermal treating Y2O3 at 150 oC for 12 h in 15 ml of 2 mol/L NaOH solution with and without PVA or PEG. It was suggested that the characteristic preferential growth of Y(OH)3 was attributed to the structure anisotropy of hexahedron Y(OH)3. The addition of PVA or PEG could promote the forming process of nanotubes by selective adsorption on different crystal planes, which altered the growth rate along different directions and resulted in the diffusion limit of constructing ions in the center top of rods. Finally, Y(OH)3:Eu and Y2O3:Eu nanotubes were also synthesized by using this method, and their photoluminescence properties were evaluated.展开更多
This work focused on the zinc powder coated with Y(OH)3 microparticles by means of ultrasonic immersion for performance improvement of zinc electrodes in alkaline battery systems.Scanning electron microscopy and other...This work focused on the zinc powder coated with Y(OH)3 microparticles by means of ultrasonic immersion for performance improvement of zinc electrodes in alkaline battery systems.Scanning electron microscopy and other characterization techniques were applied to examine the influence of the ultrasonic power on the sonochemical growth of Y(OH)3 microparticles in direct contact with zinc powder.Electrochemical properties of zinc electrodes containing Y(OH)3 microparticles were discussed through the measurement...展开更多
基金Project(51274242)supported by the National Natural Science Foundation of China
文摘Surface tension of sodium aluminate solution and the contact angle between Al（OH）3 particles and aluminate solution were measured, then the dependence of Al（OH）3 solubility on its particle size was calculated and thus the variation of the critical nucleus sizes was determined based on the Ostwald ripening formula. The results show that the Al（OH）3 solubility in sodium aluminate solution decreases with the increment of particle size, and the critical nucleus sizes increase with the rise of alkali concentration, caustic ratio and precipitation temperature. The results also imply that the presence of small particles in seeded precipitation system is an important factor to limit the depth of precipitation.
基金Program for Changjiang Scholars and Innovative Research Team in University (IRT0730)Chinese Ministry of Education Foundation for Core Young Teacher at University (GG-430-10403-1970)+1 种基金the Key Project of Department of Science and Technology of Jiangxi ProvinceProject of Education Department of Jiangxi
文摘The phase and morphology transformation during the hydrothermal treating process of Y2O3 was evaluated with X-ray difference (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), particle size and specific surface area determination. The results showed that the cubic Y2O3 did not transfer into hexagonal Y(OH)3 in pure water. Therefore, pure hexagonal Y(OH)3 with nanotube and microrod morphologies were obtained by hydrothermal treating Y2O3 at 150 oC for 12 h in 15 ml of 2 mol/L NaOH solution with and without PVA or PEG. It was suggested that the characteristic preferential growth of Y(OH)3 was attributed to the structure anisotropy of hexahedron Y(OH)3. The addition of PVA or PEG could promote the forming process of nanotubes by selective adsorption on different crystal planes, which altered the growth rate along different directions and resulted in the diffusion limit of constructing ions in the center top of rods. Finally, Y(OH)3:Eu and Y2O3:Eu nanotubes were also synthesized by using this method, and their photoluminescence properties were evaluated.
基金supported by the Innovation Foundation of BUAA for Ph. D Graduates Provided by Beihang University in China
文摘This work focused on the zinc powder coated with Y(OH)3 microparticles by means of ultrasonic immersion for performance improvement of zinc electrodes in alkaline battery systems.Scanning electron microscopy and other characterization techniques were applied to examine the influence of the ultrasonic power on the sonochemical growth of Y(OH)3 microparticles in direct contact with zinc powder.Electrochemical properties of zinc electrodes containing Y(OH)3 microparticles were discussed through the measurement...
