【作者】 付秋月；

【导师】 郝素娥；

【作者基本信息】 哈尔滨工业大学 ， 无机化学， 2008， 硕士

【摘要】 采用共沉淀法制备了AZO粉体,对所制备的AZO粉体进行了稀土La的气相扩渗改性,对改性前后AZO粉体的组成、结构和导电性能的变化进行了研究;并将改性AZO粉体应用于导电胶的制备,对所制备的导电胶的力学性能和导电性能进行了研究。共沉淀法制备AZO粉体的工艺条件为:反应温度50℃,反应溶液pH=7,烘干温度150℃,烘干时间10h,焙烧温度500℃,焙烧时间2h。采用共沉淀法制备出的AZO粉体粒度分布均匀,粒径较小,可以达到纳米级别,电阻率为4.24×107? cm。稀土La气相扩渗能进一步改善AZO粉体的导电性能。正交实验结果表明,当Al掺杂浓度为3.0wt%、La扩渗浓度为2wt%、扩渗温度为480℃、扩渗时间为5h时,改性AZO粉体的室温电阻率为1.37×104? cm。扩渗前后粉体的电阻率下降了3个数量级。XRD测试结果表明,改性AZO粉体和ZnO粉体相对比,主体特征峰没有明显变化,但分别在11o和68.5o出现了与La有关的特征峰。SEM测试表明AZO粉体经稀土La扩渗后有大的晶粒出现,存在明显的团聚现象。EDAX测试结果表明La已进入AZO粉体,并导致导电性能的提高。以所制备的改性AZO粉体为导电填料,不饱和聚酯树脂为基体制备了导电胶。当固化剂和促进剂的添加量为2wt%时,所制备出的样品表面平整无龟裂现象,反应速度适中。制备出的导电胶的电阻率最低值为5.3×105? cm。随着改性AZO粉体添加量的增加,剪切强度逐渐变小,冲击强度逐渐增大。当改性AZO粉体添加量为40wt%时,剪切强度为11.48MPa,冲击强度为19.6kJ m-2,满足应用要求。更多还原

【Abstract】 AZO powders were prepared by co-precipitation method. After that gaseous penetration of rare-earth element La was carried out to modify the AZO powders. The composition, structure and conductivity after modification were studied. The AZO powders were applied to the preparation of conductive glues. The mechanical and conductive properties of the prepared glues were investigated.The method to prepare the AZO powders by co-precipitation was that the reaction time was 50℃, the pH value of the solution was 7, the drying temperature was 150℃, drying time was 10h, the calcinations temperature was 500℃and calcinations time was 2h. The AZO powders prepared through co-precipitation exhibited an even distribution of grain size, which could reach nanometer scale. The resistivity of such powder was 4.24×107? cm. Modifying such powder with La by gaseous penetration could further improve the conductivity of AZO powders. The results of orthogonal experiment showed that the resistivity of modified AZO powders reach 1.37×104? cm when Al doping content is 3.0wt%, La doping content was 2.0wt%, penetration temperature was 480℃and penetration time is 5h. The resistivity after penetration dropped three orders of magnitude. XRD results showed that, compared with ZnO powders, the main peaks of modified AZO powders showed no obvious difference, but new peaks at 11o and 68.5o, which were related to La element. SEM results showed that there were large grains and obvious agglomeration after La penetration into AZO powders. EDAX results showed that La entered AZO and rendered the improvement of conductivity.Conductive glues were prepared with the prepared AZO powders as conductive fillings and unsaturated polyester resin as matrix. When the additive amount of curing agent and accelerant are 2wt%, the surface of samples prepared was smooth and free of cracks, and the reaction speed was moderate. The resistivity reached the lowest point of 5.3×105? cm. As the additive amount of modified AZO powders increased, the shear strength gradually decreased and the impact strength gradually increased. When the additive amount of modified AZO powders was 40wt%, the shear strength was 11.48MPa and the impact strength was 19.6kJ m-2, which could meet the need of application.更多还原