【作者】 郝艳霞；

【导师】 陆路德； 汪信； 杨绪杰；

【作者基本信息】 南京理工大学 ， 应用化学， 2003， 博士

【摘要】 本论文主要研究了氧化锆多孔膜的制备方法和氧化铝、氧化锆涂层在碳纤维／环氧基复合材料中的应用。对所制多孔膜（氧化锆、钇稳定氧化锆和氧化铝-氧化锆）的物相组成、热稳定性、微观结构以及孔性能进行了表征；分析了涂层对复合材料的界面性能、力学性能和耐热性能的影响。全文的主要内容如下： 采用硬脂酸溶胶凝胶法制备了氧化锆（ZrO₂）、钇稳定氧化锆（YSZ）纳米晶，对反应历程、不同温度下ZrO₂、YSZ的物相组成和晶粒粒径进行分析。考察超细氧化锆粉体在水相中的分散行为，得到较适宜的分散条件，并采用固态粒子烧结法制备了管式担载YSZ膜。所制的YSZ膜最可几孔直径为87nm，孔径主要集中在20～100nm。 首次以氧氯化锆（及硝酸钇）为原料采用离子交换法制备了稳定的氢氧化锆（及YSZ）溶胶，并在管式支撑体上获得了完整、无缺陷的YSZ膜。氮气吸附实验表明，700℃热处理后YSZ膜的最可几孔径小于3nm，经900℃热处理后其最可几孔径增大为3.8nm。通过差热分析（DTA）、傅立叶红外光谱（FT-IR）和X射线粉末衍射（XRD）研究发现，此方法得到的氧化锆膜400℃～600℃之间晶型为四方相，700℃时开始有少量的单斜相氧化锆出现，到900℃时已全部转变成单斜相。3mol％的Y₂O₃稳定的YSZ膜到900℃时仍为四方相。 以异丙醇铝和氧氯化锆为原料，用溶胶-凝胶法在氧化铝管式支撑体和中空纤维支撑体上成功地制备了无缺陷的Al₂O₃／ZrO₂复合膜。详细研究了Al₂O₃／ZrO₂的摩尔比对复合膜晶化温度、晶形及孔结构的影响。结果表明，由Al₂O₃和ZrO₂制成的复合膜的热稳定性比单一氧化铝或氧化锆膜的热稳定性有显著的提高。在Al₂O₃／ZrO₂的摩尔比大于0.1小于等于1的范围内，1100℃之前复合膜只以t-ZrO₂存在，1200℃时复合膜的主晶相为t-ZrO₂，并出现少量的m-ZrO₂或m-ZrO₂和α-Al₂O₃相。氮气吸附结果显示，配比不同的各复合膜经700℃烧结后，其最可几孔径集中分布在4～5nm之间。但随着氧化锆比例的增大，复合膜的比表面积、孔体积即孔隙率呈明显下降的趋势。发现Al₂O₃／ZrO₂的摩尔比为1的复合膜，当热处理温度由700℃升高1100℃时，其最可几孔径保持在4.3nm左右，而复合膜的比表面积和孔体积相应地下降。但复合膜孔结构的热稳定性要好于本论文中制备和文献报道YSZ膜。气体渗透实验表明，所制的复合膜具有一定的气体选择性。但随着氧化锆比例的增大，复合膜的比表面积、孔体积即孔隙率呈明显下降的趋势。发现Al₂O₃／ZrO₂的摩尔比为1的复合膜，当热处理温度由700℃升高1100目录博士论文℃时，其最可几孔径保持在4.3lun左右，而复合膜的比表面积和孔体积相应地下降。但复合膜孔结构的热稳定性要好于本论文中制备和文献报道YSZ膜。气体渗透实验表明，所制的复合膜具有一定的气体选择性。 采用溶胶一凝胶法在碳纤维的表面制备了均匀的A12O3、YSZ涂层。力学性能分析表明:AbO3涂层后碳纤维/环氧基复合材料的层间剪切强度相对于未涂层碳纤维/环氧基复合材料的层间剪切强度提高17.7%;YSZ涂层碳纤维/环氧基复合材料的层间剪切强度提高了近52.0%，并且拉伸强度和弯曲强度均稍有提高。热重分析表明，碳纤维表面的A120:或YSZ涂层在350℃一700℃能有效地减缓碳纤维环氧基复合材料的氧化失重速率。更多还原

【Abstract】 The preparation methods of porous zirconia membrane and the application of alumina and zirconia coatings in carbon fiber strengthening epoxy resin composites were investigated in this dissertation. The phase components, thermal stability, microstructure and pore properties of porous membrane (ZrO2, YSZ and Al2O3-ZrO2 ) were characterized. The effects of coatings on the interfacial performance, mechanical property, thermal resistant property of composites were studied. The dissertation was mainly discussed as follows:The nanocrystalline of zirconia and yttria-stabilized zirconia (YSZ) were prepared by stearic acid method. The reaction process, crystalline phase and particle size of ZrO2 and YSZ particles treated at different temperatures were investigated. The ideal dispersion conditions of ZrO2 powders prepared in water were obtained by the study of dispersion behavior. Then, the supported YSZ membrane whose most concentrative pore diameter is about 87 nm was prepared and its pore diameters concentrate into 20~100nm.The stable YSZ sol and defect-free YSZ membranes supported by tube were firstly prepared by anionic exchange method using zirconyl chloride as raw materials. Results of nitrogen isothermal absorption measurement show that the most concentrative pore diameter of YSZ membrane calcined at 700C is less than 3 nm and is 3.8nm at 900C. It is found that the crystal phases of ZrO2 membranes from 400C to 600C are tetragonal, monoclinic ZrO2 appear at 700C and the crystal phases of 3mol% YSZ membranes are still tetragonal at 900 C by differential thermal analysis(DTA), X-ray diffraction (XRD) and fourier transform infrared spectroscopy (FT-IR).The defect-free Al2O3-ZrO2 composite membranes supported by hollow fiber and ceramic tube were prepared by sol-gel process from aluminium iso-propoxide and zirconyl chloride as their precursors. The effects of mole ratio of alumina and zirconia in composite membranes on crystal temperature, crystal phase and pore structure were investigated in detail. The results show that the thermal stability of composite membranes is greatly improved compared to pure Al2O3 or ZrO2 membranes. When the mole ratio of alumina and zirconia ranged between 0.1 and 1, the crystal phase ofcomposite membranes is tetragonal ZrO2 until 1100C, but its main crystal phase is still tetragonal and monoclinic ZrO2 or monoclinic ZrO2 and alpha Al2O3 appear at 1200C. Results of nitrogen isothermal absorption measurement show that the most concentrative pore diameters of composite membranes calcined at 700 C with different mole ratio of alumina and zirconia concentrate into 4~5nm, but the specific surface areas and pore volume of composite membranes decrease with the increase of zirconia. It is found that most concentrative pore diameters of composite membranes with 50mol% zirconia are still about 4.3 nm and its specific surface areas decrease correspondingly when calcination temperatures increase from 700C to 1100C. However, the thermal stability of composite membranes is higher than 3mol% YSZ membranes prepared by our laboratory and reference, and gas permeation test showed that the membranes have gas selectivity.The homogenous alumina and YSZ coatings on carbon fiber were prepared by sol-gel method. The results of mechanical property analysis show that the interlaminar shear strength (ILSS) of alumina-coated carbon fiber reinforced epoxy resin composites is enhanced 17.7%, the ILSS of YSZ-coated carbon fiber composites is enhanced 52.0% compared to uncoated carbon fiber composites, and bending strength and tensile strength are improved slightly at the same time. The results of thermogravimetric analysis show that alumina and YSZ coatings on carbon fiber can effectively slower the weight loss rate of composites resulting from oxidation in the range of 3 50 C to 700 C.更多还原