Yttrium isopropoxide was prepared directly by the reaction between yttrium and isopropyl alcohol using mercuric chloride and iodine as catalyst. Yield is above 83% . This method possesses the merits of easy operationa...Yttrium isopropoxide was prepared directly by the reaction between yttrium and isopropyl alcohol using mercuric chloride and iodine as catalyst. Yield is above 83% . This method possesses the merits of easy operational approach, high product purity, high reaction rate and high production rate. Compared with the previous reported results , the period needed was shortened by 19 h and the yieid increased by 8% . The period needed for preparation is about 5 hows. These results are better than the present report . The dehydrolysis method of isopropyl alcohol and the composition of catalyst were presented.展开更多
By using self-made metal-alkoxide yttrium isopropoxide as a sintering additive and disperser of whisker, the SiC whisker reinforced AIN ceramics was prepared. Its apparent density is 99.5 percent of the theoretical de...By using self-made metal-alkoxide yttrium isopropoxide as a sintering additive and disperser of whisker, the SiC whisker reinforced AIN ceramics was prepared. Its apparent density is 99.5 percent of the theoretical density; its flexural strength and fracture toughness are 681 MPa and 5.21 MPa·m1/2 respectively. Comparing the result with that by applying Y2O3 powder as a sintering additive, the flexural strength is increased by 25% and the fracture toughness is increased by 33% . The dispersity of whisker by increased yttrium isopropoxide is significantly better than that by Triton X-100.展开更多
The nanostructured titanium dioxide(TiO_(2))thin films have been prepared for the molar concentrations of titanium tetra isopropoxide(TTIP)0.05 M,0.1 M,0.15 M and 0.2 M by sol-gel routed spin coating technique with ca...The nanostructured titanium dioxide(TiO_(2))thin films have been prepared for the molar concentrations of titanium tetra isopropoxide(TTIP)0.05 M,0.1 M,0.15 M and 0.2 M by sol-gel routed spin coating technique with calcination at 450℃.The processing parameters such as,pH value(8),catalyst HCl(0.1 ml),spin speed(3000 rpm)and calcination temperature(450℃)are optimized.The crystalline nature and surface morphology were analyzed by XRD,SEM and AFM analysis.The XRD results confirm that the films are crystalline with anatase phase,and are nanostructured.The SEM micrographs of the TiO_(2) film reveal the spherical nature of the particle.AFM analysis establishes that the uniformity of the TiO_(2) thin film was optimized at 0.2 M.The optical measurements show that the transmittance depends on the molarity,and the optical band gap energy of TiO_(2) films is found to be inversely proportional to molarity.The I-V characteristics exhibit that the molarity strongly influences the electrical conductivity of the film.The results indicate that the significant effect of molarity on structural,optical and electrical properties of the nanostructured TiO_(2) thin films will be useful to photovoltaic application.展开更多
基金This work was funded by National '863' Foundation (863-715-020-01-01)
文摘Yttrium isopropoxide was prepared directly by the reaction between yttrium and isopropyl alcohol using mercuric chloride and iodine as catalyst. Yield is above 83% . This method possesses the merits of easy operational approach, high product purity, high reaction rate and high production rate. Compared with the previous reported results , the period needed was shortened by 19 h and the yieid increased by 8% . The period needed for preparation is about 5 hows. These results are better than the present report . The dehydrolysis method of isopropyl alcohol and the composition of catalyst were presented.
文摘By using self-made metal-alkoxide yttrium isopropoxide as a sintering additive and disperser of whisker, the SiC whisker reinforced AIN ceramics was prepared. Its apparent density is 99.5 percent of the theoretical density; its flexural strength and fracture toughness are 681 MPa and 5.21 MPa·m1/2 respectively. Comparing the result with that by applying Y2O3 powder as a sintering additive, the flexural strength is increased by 25% and the fracture toughness is increased by 33% . The dispersity of whisker by increased yttrium isopropoxide is significantly better than that by Triton X-100.
文摘The nanostructured titanium dioxide(TiO_(2))thin films have been prepared for the molar concentrations of titanium tetra isopropoxide(TTIP)0.05 M,0.1 M,0.15 M and 0.2 M by sol-gel routed spin coating technique with calcination at 450℃.The processing parameters such as,pH value(8),catalyst HCl(0.1 ml),spin speed(3000 rpm)and calcination temperature(450℃)are optimized.The crystalline nature and surface morphology were analyzed by XRD,SEM and AFM analysis.The XRD results confirm that the films are crystalline with anatase phase,and are nanostructured.The SEM micrographs of the TiO_(2) film reveal the spherical nature of the particle.AFM analysis establishes that the uniformity of the TiO_(2) thin film was optimized at 0.2 M.The optical measurements show that the transmittance depends on the molarity,and the optical band gap energy of TiO_(2) films is found to be inversely proportional to molarity.The I-V characteristics exhibit that the molarity strongly influences the electrical conductivity of the film.The results indicate that the significant effect of molarity on structural,optical and electrical properties of the nanostructured TiO_(2) thin films will be useful to photovoltaic application.
