The solubility of zinc oxide in sodium hydroxide solution was measured in a closed polytetrafluoroethylene vessel from 25 to 100 ℃. The ZnO solubility was determined by employing the method of isothermal solution sat...The solubility of zinc oxide in sodium hydroxide solution was measured in a closed polytetrafluoroethylene vessel from 25 to 100 ℃. The ZnO solubility was determined by employing the method of isothermal solution saturation. The results show that only ZnO solid exists in the equilibrium state in the low concentration alkali regions, and the solubility of zinc oxide is almost invariable with temperature. With the increase of alkali concentration, equilibrium solid turns from ZnO to NaZn（OH）3 suddenly, this mutation is called invariant point. The alkali concentration of the invariant points increases with increasing temperature, but the solubility of NaZn（OH）3 decreases with increasing alkali concentration at the same temperature. At the same Na2O concentration, the higher the temperature is, the higher the solubility of NaZn（OH）3 is.展开更多
Zinc oxide was synthesized from zinc sulphate using different reducing agents under microwave irradia- tion. The influence of sodium borohydride, hydrazine hydrate and urea on the shape and size of the products were i...Zinc oxide was synthesized from zinc sulphate using different reducing agents under microwave irradia- tion. The influence of sodium borohydride, hydrazine hydrate and urea on the shape and size of the products were investigated by scanning electron microscopy （SEM） and X-ray diffraction （XRD）. SEM showed the nano-sized spherical and rectangular shaped structures in case of sodium borohydride and hydrazine hydrate, whereas micro-sized hexagonal structures were formed in case of urea under the same irradiation power. The reducing agents played an important role in forming the various structures. Thus different shapes and size of structures were produced by only varying the reducing agent, which had wide applications in various fields.展开更多
基金Project (2007CB613603) supported by the National Basic Research Program of China
文摘The solubility of zinc oxide in sodium hydroxide solution was measured in a closed polytetrafluoroethylene vessel from 25 to 100 ℃. The ZnO solubility was determined by employing the method of isothermal solution saturation. The results show that only ZnO solid exists in the equilibrium state in the low concentration alkali regions, and the solubility of zinc oxide is almost invariable with temperature. With the increase of alkali concentration, equilibrium solid turns from ZnO to NaZn（OH）3 suddenly, this mutation is called invariant point. The alkali concentration of the invariant points increases with increasing temperature, but the solubility of NaZn（OH）3 decreases with increasing alkali concentration at the same temperature. At the same Na2O concentration, the higher the temperature is, the higher the solubility of NaZn（OH）3 is.
基金Financial assistance from CPRI, Bangalore and SEM analysis from Tezpur University
文摘Zinc oxide was synthesized from zinc sulphate using different reducing agents under microwave irradia- tion. The influence of sodium borohydride, hydrazine hydrate and urea on the shape and size of the products were investigated by scanning electron microscopy （SEM） and X-ray diffraction （XRD）. SEM showed the nano-sized spherical and rectangular shaped structures in case of sodium borohydride and hydrazine hydrate, whereas micro-sized hexagonal structures were formed in case of urea under the same irradiation power. The reducing agents played an important role in forming the various structures. Thus different shapes and size of structures were produced by only varying the reducing agent, which had wide applications in various fields.
