【摘要】 以水和叔丁醇为分散介质,分别利用烘箱和真空冷冻干燥机对混酸处理后的碳纳米管进行干燥处理,并利用扫描电子显微镜及紫外可见分光光度计等对干燥前后碳纳米管的形貌及再分散性进行表征。研究结果表明:以水为分散介质,采用真空冷冻干燥所得碳纳米管粉体的再分散性比烘箱干燥的差;而以叔丁醇为分散介质时,真空冷冻干燥所得碳纳米管粉体的再分散性比烘箱干燥的好;干燥方法相同时,叔丁醇是更好的分散介质。以叔丁醇为分散介质,经真空冷冻干燥后,碳纳米管再分散性最好,可达到干燥前的91.2%。这应归因于:分散介质适当时,真空冷冻干燥能减弱毛细管压力、氢键及化学键合等引起的团聚趋势,从而能得到再分散性更好的碳纳米管粉体。更多还原

【Abstract】 Carbon nanotubes were dispersed in water or tert butyl alcohol(TBA) after they were treated by acid.These two kinds of suspensions were dried by oven or vacuum freeze dryer.Scanning electron microscopy(SEM) and UV-Vis spectrophotometer were used in characterizing the morphology and re-dispersibility of CNTs before and after drying processes.The results show that when the dispersing agent is water,the re-dispersibility of CNTs dried by vacuum freeze dryer is worse than that by oven.However,when TBA is used as the dispersing agent,the re-dispersibility of CNTs dried by vacuum freeze dryer is better than that by oven.It is also shown that it is better to choose TBA as the dispersing agent. Comparatively,optimal re-dispersibility of CNTs could be obtained by vacuum freeze-drying method with TBA as dispersing agent,which could reach 91.2% of the dispersity of the original acid-treated CNTs suspension.This should be attributed to the fact that when the dispersing agent is suitable,vacuum freeze-drying could decrease the aggregation caused by capillary pressure,hydrogen and chemical bonding.更多还原