纳米钴蓝共沉淀法制备技术

以硝酸钴、硝酸铝为原料,NaOH或尿素为沉淀剂,采用共沉淀法制备纳米钴蓝。考察了Co/Al摩尔比、沉淀剂种类和煅烧温度等因素对纳米钻蓝呈色性能影响,采用包括可见光分度计等多种方法表征了纳米钴蓝的结构及形貌特征及纳米钴蓝色度值。研究结果表明:(1)煅烧温度为1000℃时,当Co/Al摩尔比从1∶3升至1∶1,钴蓝颜色从蓝色依次向蓝绿色、暗绿色转变,同时,以NaOH为沉淀剂制备的钴蓝其亮度比以尿素为沉淀剂制备的钴蓝高;(2)以NaOH为沉淀剂,Co/Al摩尔比为1∶3时,当煅烧温度为900℃,钴蓝呈蓝绿色,当煅烧温度为1000-1100℃,钴蓝呈蓝色;(3)钴蓝不同制备工艺会改变钴d电子层状态,导致钴蓝呈现不同颜色,最终优化工艺制备的纳米钴蓝粒径为45-65nm,呈尖晶石型晶体结构,色度值为CIE(35.86,-12.63,-34.83)。

Preparation of Nano Cobalt Blue through Co-precipitation Method

Nano cobalt blue was prepared with cobalt and nitrite aluminum nitrate as raw materials and NaOH or urea as precipitator.The effects of Co/Al molar ratio,precipitator and calcination temperature on the color of the nano cobalt blue were investigated.The structure,morphology and CIE value of the cobalt blue were characterized by some conventional methods including visible light spectrophotometer.The results demonstrate that:(1)When the calcination temperature is 1000℃,the color of cobalt blue changes from blue to blue-green and then dark green as the Co/Al molar ratio increases from 1∶3 to 1∶1.The prepared cobalt blue has higher brightness with NaOH as precipitator than to that with urea as precipitator.(2)When the Co/Al molar ratio is 1∶3,and NaOH as precipitator,the prepared cobalt blue exhibits blue-green and blue color with the calcination temperature of 900℃and 1000-1100℃,respectively.(3)The final optimized preparation give rise to the nano cobalt blue with a particle size of 45-65 nm,a spinel crystal structure and a CIE vale of(35.86,-12.63,-34.83).