检索规则说明:AND代表“并且”;OR代表“或者”;NOT代表“不包含”;(注意必须大写,运算符两边需空一格)
检 索 范 例 :范例一: (K=图书馆学 OR K=情报学) AND A=范并思 范例二:J=计算机应用与软件 AND (U=C++ OR U=Basic) NOT M=Visual
作 者:朱兆武[1] 龙志奇[1] 崔大立[1] 张顺利[1] 张国成[1]
机构地区:[1]北京有色金属研究总院有研稀土新材料股份有限公司,北京100088
出 处:《中国有色金属学报》2005年第3期435-440,共6页The Chinese Journal of Nonferrous Metals
基 金:国家发展与改革委员会稀土专项资助项目
摘 要:用碳酸氢铵作沉淀剂通过添加NH4NO3和(NH4)2CO4两种不同的试剂制备了超细CeO2粉体.采用X射线衍射、BET和激光散射的方法研究了不同灼烧温度下粉体粒径的变化规律,并研究了粉体粒径对紫外线吸收的影响.结果表明:NH4NO3和(NH4)2CO4作为添加剂可以制得一次粒径在10~100 nm的纳米粉体,团聚粒径在200~300 nm分散性好的超细CeO2粉体.X射线衍射和BET测得的一次粒径随灼烧温度升高呈明显增大的趋势,激光散射测得的团聚粒径随灼烧温度变化不明显.CeO2粉体分散在去离子水中的吸收光谱研究表明,粉体一次粒径大小对光的吸收效果有明显影响,粒径小,紫外线吸收效果好,可见光穿透性强,粒径增大,粉体将失去紫外线吸收效果,紫外吸收受粉体的团聚粒径影响不大.Ultra-fine CeO_2 particle-sized powders were prepared by precipitation method with bicarbonate as precipitant while NH_4NO_3 and (NH_4)_2CO_4 serve as additives, respectively. The variant regularity of particle size with calcinations temperatures was studied by XRD, BET and Lazer Scattering methods. The results show that nano-particle sized CeO_2 with primary particle size of 10100nm and aggregated particle size of 200300nm can be obtained while NH_4NO_3 and (NH_4)_2CO_4 serves as additive. The primary particle size determined by XRD and BET method increases significantly with temperature, however the secondary particle size dose not change appreciably analyzed by laser scattering method. As CeO_2 dispersed in de-ionized water, ultra violet(UV)-visible absorbance spectrum was applied to study its absorbance characters. The study finds that it has good UV absorbance and visible light transparency as CeO_2 powder with an ultra-fine particle size. UV absorbance is greatly influenced by the primary particle size. With the primary particle size increase, the UV absorbance weakens markedly. The secondary particle size has little influence on its UV absorbance.
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在链接到云南高校图书馆文献保障联盟下载...
云南高校图书馆联盟文献共享服务平台 版权所有©
您的IP:216.73.216.30