The thermal decomposition processes in solid state CoC2O4·2H2O have been studied in air using TG/DTA, DSC and XRD techniques. TG/DTA, DSC curves showed that the decomposition proceeded through two well-defined st...The thermal decomposition processes in solid state CoC2O4·2H2O have been studied in air using TG/DTA, DSC and XRD techniques. TG/DTA, DSC curves showed that the decomposition proceeded through two well-defined steps in air. Mass loss of the thermal decomposition of CoC2O4·2H2O was in good agreement with the theoretica1 one. XRD showed that the final product of the thermal decomposition was Co3O4. The activation energies were calculated through the ASTM E698 and Flynn-Wall-Ozawa (FWO) methods, and the possible conversion functions had been estimated through the multiple-linear regression method. The activation energies for the two steps decomposition of CoC2O4·2H2O were 140.18 kJ·mol-1 and 134.61 kJ·mol-1, respective1y.展开更多
Both whisker and nanometer MgSO4·5Mg(OH)2·3H2O(MOS) were prepared by hydrothermal method at 140℃for different times, using NaOH and MgSO4·7H2O as raw materials. The MgSO4·5Mg(OH)2·3H2O part i...Both whisker and nanometer MgSO4·5Mg(OH)2·3H2O(MOS) were prepared by hydrothermal method at 140℃for different times, using NaOH and MgSO4·7H2O as raw materials. The MgSO4·5Mg(OH)2·3H2O part icles were characterized by powder X ray diffraction(XRD),thermal analysis(TGA DSC), infrared spectroscopy(FT IR),transmission electron microscopy(SEM) and scanning electron microscopy(TEM). The size distribution in whisker like and nanocrystalline materials arein the range of 10～50μm and 10～20nm respectively. The whisker MOS is metastable phase in MgSO4 NaOH H2O system at 140℃,whereas nanometer MOS is stable phase.展开更多
文摘The thermal decomposition processes in solid state CoC2O4·2H2O have been studied in air using TG/DTA, DSC and XRD techniques. TG/DTA, DSC curves showed that the decomposition proceeded through two well-defined steps in air. Mass loss of the thermal decomposition of CoC2O4·2H2O was in good agreement with the theoretica1 one. XRD showed that the final product of the thermal decomposition was Co3O4. The activation energies were calculated through the ASTM E698 and Flynn-Wall-Ozawa (FWO) methods, and the possible conversion functions had been estimated through the multiple-linear regression method. The activation energies for the two steps decomposition of CoC2O4·2H2O were 140.18 kJ·mol-1 and 134.61 kJ·mol-1, respective1y.
文摘Both whisker and nanometer MgSO4·5Mg(OH)2·3H2O(MOS) were prepared by hydrothermal method at 140℃for different times, using NaOH and MgSO4·7H2O as raw materials. The MgSO4·5Mg(OH)2·3H2O part icles were characterized by powder X ray diffraction(XRD),thermal analysis(TGA DSC), infrared spectroscopy(FT IR),transmission electron microscopy(SEM) and scanning electron microscopy(TEM). The size distribution in whisker like and nanocrystalline materials arein the range of 10～50μm and 10～20nm respectively. The whisker MOS is metastable phase in MgSO4 NaOH H2O system at 140℃,whereas nanometer MOS is stable phase.
