Synthesis and characterization of ultrafine Co2AlO4 pigment by freeze–drying
Synthesis and characterization of ultrafine Co2AlO4 pigment by freeze–drying
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DOI：
10.1016/j.powtec.2012.04.029
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发表时间：
2012-08
影响因子：
5.2
通讯作者：
X. Xi;Z. Nie;Liwen Ma;Le Li;Xiangyang Xu;T. Zuo
中科院分区：
文献类型：
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作者：
X. Xi;Z. Nie;Liwen Ma;Le Li;Xiangyang Xu;T. Zuo
研究了冷冻干燥法制备钴蓝颜料（CoAl 2 O 4）的工艺。以醋酸钴[Co（CH 3COO）2. 4 H2O]和硫酸铝[Al 2（SO 4）3. 18 H2O]为原料，以液氮为低温介质制备了钴蓝纳米粉体。采用预冷冻喷雾、真空干燥、煅烧等工艺制备了Co/Al=1：2和1：2.4的钴蓝纳米粉体样品。采用X射线衍射、透射电子显微镜和紫外光谱对冻干前体和煅烧产物进行了分析。冷冻干燥的前体是无定形的。煅烧温度为750°C时生成Co2 AlO 4，900°C时由Co2 AlO 4转变为CoAl 2 O 4，粒径约为25 nm。煅烧温度越高，结晶度越大。Co/Al=1：2的钴蓝颜料比1：2.4的样品颜色更浅但更饱和。提高煅烧温度和延长煅烧时间可以优化颜料的光学性能。
The preparation of cobalt blue pigment (CoAl2O4) using freeze–drying technology was investigated. Cobalt blue nanopowder was prepared using cobalt acetate [Co(CH3COO)2·4H2O] and aluminum sulfate [Al2(SO4)3·18H2O], with liquid nitrogen as the cryogenic medium. Cobalt blue nanopowder samples with Co/Al=1:2 and 1:2.4 were obtained by using processes including pre-freezing spraying, vacuum drying, and calcination. X-ray diffraction, transmission electron microscopy and ultraviolet spectroscopy were used to analyze the freeze-dried precursors and calcined products. The freeze-dried precursor was amorphous. Co2AlO4appeared at the calcination temperature of 750°C, while CoAl2O4was converted from Co2AlO4at 900°C, and the particle size was about 25nm. The higher the calcination temperature, the greater the degree of crystallization. The cobalt blue pigment with Co/Al=1:2 was a lighter but more saturated color than the 1:2.4 sample. Increasing the calcination temperature and lengthening the time could optimize the optical performance of the pigment.