| 초록 |
Influence of flow motion on morphology and structure of Copper sulfide nanocrystals produced by Cu2+/BPEI-sulfur reaction in the presence of ascorbic acid was studied using mixing tank (MT) crystallizer and Couette-Taylor (CT) crystallizer in batch and continuous operation. In batch operation, only Cu7S4 nanocrystal with morphology of fiber was obtained when the agitation speed was at range of 50-1000 rpm in MT crystallizer. In continuous operation, the mean residence time was set at 2.5 min and keeping the same condition with batch operation, pure Cu7S4 nanocrystal with hexagonal plate could be synthesized in CT crystallizer and MT crystallizer when the rotating speed was or greater than 90 rpm, while the morphology of Cu7S4 would change to the fiber when the rotating speed was or less than 80 rpm. If the rotation speed continuously reduced down to 5 rpm, new pure nanocrystal Cu39S28 was appeared in CT crystallizer. On the basis of morphology and composition change, the flow motion in CT crystallizer and MT crystallizer had a significant effect on morphology and structure of copper sulfide in this continuous operation. |
