采用脉冲电化学沉积法成功地在生物医用钛金属表面制备出均匀的纳米HA/ZrO2复合涂层.通过热处理提高涂层的致密性,同时保留涂层的微纳结构.考察了热处理后复合涂层的成分、形貌、生物相容性及生理稳定性.X射线衍射分析表明,复合涂层成分...采用脉冲电化学沉积法成功地在生物医用钛金属表面制备出均匀的纳米HA/ZrO2复合涂层.通过热处理提高涂层的致密性,同时保留涂层的微纳结构.考察了热处理后复合涂层的成分、形貌、生物相容性及生理稳定性.X射线衍射分析表明,复合涂层成分为HA和ZrO2.扫描电镜观察发现,热处理后复合涂层的致密性有所提高.研究发现,ZrO2的加入大大降低了HA/ZrO2复合涂层中钙离子的释放速度,提高了HA/ZrO2复合涂层的生理稳定性.纳米划痕实验结果表明,HA/ZrO2复合涂层具有较好的结合强度.通过培养成骨细胞考察了复合涂层的生物相容性.A lam ar B lue检测表明,HA/ZrO2复合涂层表面细胞黏附及增殖能力较好.ALP检测发现,热处理后HA/ZrO2复合涂层表面的细胞分化能力较强.综合细胞培养结果显示,HA/ZrO2复合涂层有较好的生物相容性.展开更多
Sulfated zirconia-lanthana (SO4^2-/ZrO2-La2O3) precursors were prepared by ultrasonic coprecipitation method and followed by aging at different temperature. The precursors were treated by 0.5 mol/L H2SO4. Samples of...Sulfated zirconia-lanthana (SO4^2-/ZrO2-La2O3) precursors were prepared by ultrasonic coprecipitation method and followed by aging at different temperature. The precursors were treated by 0.5 mol/L H2SO4. Samples of SO4^2-/ZrO2-La2O3 nano-crystalline catalysts were obtained by baking the treated precursors at different temperatures. The acidic properties of SO4^2-/ZrO2-La2O3 were tested by the Hammett indicator method. The phase composition, specific area, particle structure, and surface state were characterized by X-ray diffraction, BET, transmission electron microscopy, infrared spectrum, and X-ray photoelectron spec- troscopy. The catalytic activities were estimated by esterification of acetic acid with glycerin. It was shown that the catalyst prepared by ultrasonic stirring and low temperature (-15 ℃) exhibited highly active sites and high catalytic property.展开更多
A sustainable process was explored for the preparation of 5-hydroxymethylfurfural(HMF) by catalytic degradation of the waste cotton stalk. Solid super-acid(SO_42-/ZrO_2) was used as an efficient catalyst for the de...A sustainable process was explored for the preparation of 5-hydroxymethylfurfural(HMF) by catalytic degradation of the waste cotton stalk. Solid super-acid(SO_42-/ZrO_2) was used as an efficient catalyst for the degradation of cotton stalk. Both decomposition experiments and kinetic study were conducted for the exploration of degradation condition and kinetics mechanism. The optimized experimental conditions are reaction temperature 503 K, reaction time 75 min and dosage of catalyst 30%(mass fraction) based on the decomposition experiments, under which a maximum yield of 27.2% for HMF could be achieved. Kinetic study was then carried out in the presence of SO_42-/ZrO_2. The theoretical results indicate that the activation energies for reducing sugar and HMF with catalyst are 96.71 k J/mol, 84.21 kJ/mol in the presence of SO_42-/ZrO_2, and they are 105.96 k J/mol and 119.37 k J/mol in the absence of SO_42-/ZrO_2.展开更多
摘要采用脉冲电化学沉积法成功地在生物医用钛金属表面制备出均匀的纳米HA/ZrO2复合涂层.通过热处理提高涂层的致密性,同时保留涂层的微纳结构.考察了热处理后复合涂层的成分、形貌、生物相容性及生理稳定性.X射线衍射分析表明,复合涂层成分为HA和ZrO2.扫描电镜观察发现,热处理后复合涂层的致密性有所提高.研究发现,ZrO2的加入大大降低了HA/ZrO2复合涂层中钙离子的释放速度,提高了HA/ZrO2复合涂层的生理稳定性.纳米划痕实验结果表明,HA/ZrO2复合涂层具有较好的结合强度.通过培养成骨细胞考察了复合涂层的生物相容性.A lam ar B lue检测表明,HA/ZrO2复合涂层表面细胞黏附及增殖能力较好.ALP检测发现,热处理后HA/ZrO2复合涂层表面的细胞分化能力较强.综合细胞培养结果显示,HA/ZrO2复合涂层有较好的生物相容性.
摘要Sulfated zirconia-lanthana (SO4^2-/ZrO2-La2O3) precursors were prepared by ultrasonic coprecipitation method and followed by aging at different temperature. The precursors were treated by 0.5 mol/L H2SO4. Samples of SO4^2-/ZrO2-La2O3 nano-crystalline catalysts were obtained by baking the treated precursors at different temperatures. The acidic properties of SO4^2-/ZrO2-La2O3 were tested by the Hammett indicator method. The phase composition, specific area, particle structure, and surface state were characterized by X-ray diffraction, BET, transmission electron microscopy, infrared spectrum, and X-ray photoelectron spec- troscopy. The catalytic activities were estimated by esterification of acetic acid with glycerin. It was shown that the catalyst prepared by ultrasonic stirring and low temperature (-15 ℃) exhibited highly active sites and high catalytic property.
基金Project(2010DFA41440)supported by China-Japan International CooperationProject(2016TP1007)supported by the Hunan Provincial Science and Technology Plan,ChinaProject(21376269)supported by the National Natural Science Foundation of China
摘要A sustainable process was explored for the preparation of 5-hydroxymethylfurfural(HMF) by catalytic degradation of the waste cotton stalk. Solid super-acid(SO_42-/ZrO_2) was used as an efficient catalyst for the degradation of cotton stalk. Both decomposition experiments and kinetic study were conducted for the exploration of degradation condition and kinetics mechanism. The optimized experimental conditions are reaction temperature 503 K, reaction time 75 min and dosage of catalyst 30%(mass fraction) based on the decomposition experiments, under which a maximum yield of 27.2% for HMF could be achieved. Kinetic study was then carried out in the presence of SO_42-/ZrO_2. The theoretical results indicate that the activation energies for reducing sugar and HMF with catalyst are 96.71 k J/mol, 84.21 kJ/mol in the presence of SO_42-/ZrO_2, and they are 105.96 k J/mol and 119.37 k J/mol in the absence of SO_42-/ZrO_2.