The preparation and characterization of alkaline resistant porous ceramics from potassium titanate whiskers are studied. K2Ti4O9 whiskers in the whisker preforms （mixtures of K2Ti6O13 and K2Ti4O9） were completely co...The preparation and characterization of alkaline resistant porous ceramics from potassium titanate whiskers are studied. K2Ti4O9 whiskers in the whisker preforms （mixtures of K2Ti6O13 and K2Ti4O9） were completely converted to K2Ti6O13 at 960℃. The alkaline resistance as well as the change in bending strength, porosity and permeability of the ceramics was investigated by altering the composition of the preforms in which the content of K2Ti6O13 whiskers was higher than 50% （molar fraction）. The alkaline resistance of the porous K2Ti6O13 ceramics is found much higher than that of Al2O3 in caustic NaOH solutions, and further study indicates that the K2Ti6O13 ceramics can be stably used in solutions of pH〉2.0. The bending strength increases initially with the content of the raw K2Ti6O13 in the preforms up to 66% （molar fraction） and then decreases, contrary to the behaviors of porosity and permeability. The values of bending strength, porosity and permeability of the ceramics prepared from the preform of 80% （molar fraction） raw K2Ti6O13 whiskers are respectively 56MPa, 29.4% and 330L·m^-2〈h^-1 , which are comparable to those of the porous Al2O3 ceramics.展开更多
To promote the scale-up production and industrial application of magnesium oxide （MgO） whiskers, MgO whiskers were prepared by the calcination method of the precursor. The precursor MgSO4·5Mg（OH）2·2H2O ...To promote the scale-up production and industrial application of magnesium oxide （MgO） whiskers, MgO whiskers were prepared by the calcination method of the precursor. The precursor MgSO4·5Mg（OH）2·2H2O （152 MOS） single component was prepared by hydrothermal synthesis reaction in MgSO4 solution and NaOH solution. MgO whisker was prepared by heating treatment of the precursor at low heating speed to keep the structure of the precursor not be destroyed. The composition, the morphology and the structure of these whiskers were characterized by X-ray diffraction （XRD） and scanning electron microscopy （SEM）. The results indicate that the MgO whisker was about 0.5-1.2 μm in diameter and 20-80 μm in length, with an aspect ratio no less than 100.展开更多
基金Supported by the Funds for 0utstanding Young Researchers from the National Natural Science Foundation of China （Nos.29925616, 20428606）, the National Natural Science Foundation of China （Nos.20236010, 20246002, 20376032）, the Natural Foundation of Jiangsu Province （BK2004215）, the National High Technology Development Program of China （No.2003AA333010, No.2006AA03Z455）, the State Key Development Program for Basic Research of China （No.2003CB615700）, CNPC Program （W06-03C-01-03-02）.
文摘The preparation and characterization of alkaline resistant porous ceramics from potassium titanate whiskers are studied. K2Ti4O9 whiskers in the whisker preforms （mixtures of K2Ti6O13 and K2Ti4O9） were completely converted to K2Ti6O13 at 960℃. The alkaline resistance as well as the change in bending strength, porosity and permeability of the ceramics was investigated by altering the composition of the preforms in which the content of K2Ti6O13 whiskers was higher than 50% （molar fraction）. The alkaline resistance of the porous K2Ti6O13 ceramics is found much higher than that of Al2O3 in caustic NaOH solutions, and further study indicates that the K2Ti6O13 ceramics can be stably used in solutions of pH〉2.0. The bending strength increases initially with the content of the raw K2Ti6O13 in the preforms up to 66% （molar fraction） and then decreases, contrary to the behaviors of porosity and permeability. The values of bending strength, porosity and permeability of the ceramics prepared from the preform of 80% （molar fraction） raw K2Ti6O13 whiskers are respectively 56MPa, 29.4% and 330L·m^-2〈h^-1 , which are comparable to those of the porous Al2O3 ceramics.
文摘To promote the scale-up production and industrial application of magnesium oxide （MgO） whiskers, MgO whiskers were prepared by the calcination method of the precursor. The precursor MgSO4·5Mg（OH）2·2H2O （152 MOS） single component was prepared by hydrothermal synthesis reaction in MgSO4 solution and NaOH solution. MgO whisker was prepared by heating treatment of the precursor at low heating speed to keep the structure of the precursor not be destroyed. The composition, the morphology and the structure of these whiskers were characterized by X-ray diffraction （XRD） and scanning electron microscopy （SEM）. The results indicate that the MgO whisker was about 0.5-1.2 μm in diameter and 20-80 μm in length, with an aspect ratio no less than 100.
