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以金属锌为原料,引入偶联表面活性剂作为晶体生长控制剂,在温和的水热条件(150℃)下一步合成了花状纳米结构的ZnO.使用XRD,TEM,SEM,SAED等测试手段,对产物的化学组成和形貌特征进行了分析和表征.结果表明,花状ZnO纳米结构由ZnO纳米棒组成,该ZnO纳米棒为六方晶系且表现为单晶性质.ZnO纳米棒纯度高、粒径较小、长直、光滑而且大多一端聚集而另一端向四周放射性分布,呈较完美的花状结构.初步探讨了ZnO单晶纳米棒和花状ZnO纳米结构的形成机理.分析表明,ZnO纳米棒及其花状结构的形成与偶联表面括性剂特殊的性质及分子结构有关. 相似文献
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The oxidation of carbon nanotubes, C60 and graphite was studied by thermogravimetric (TG) analysis and differential thermal analysis (DTA) technique, and the oxidation kinetic models of three carbon materials studied were analyzed by mechanism-function method. The results indicate that three carbon species adopt different oxidation mechanisms due to their different structures. The oxidation of carbon nanotubes with cylindrical structure follows contracting volume reaction mechanism [R3 mechanism, 1 - (1 -α)1/3 = kt], indicating that the oxidation of carbon nanotubes takes place from the ends to the center. For graphite with planar sandwich structure, the oxidation starts at the edges initially and gradually moves toward the center, which corresponds to contracting area phase boundary reaction mechanism [R2 mechanism, 1 - (1 - α)1/2 = κt]. The oxidation of C60 with spherical structure,however, is complex and apparently cannot be illustrated with a single kinetic model. The values of apparent activation energy for C60 determined using Kissing method is 91kJ·mol-1. 相似文献
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采用微波加热多元醇还原的方法制备了贵金属Pt负载的TiO2纳米管复合材料,并对其形貌和结构进行了表征。结果表明,试验中所制备的TiO2纳米管直径约10nm左右,长度达到几百纳米甚至微米级。微波法负载的Pt粒子粒径分布均匀,尺寸约在4.5nm左右。电化学结果表明该复合纳米材料对甲醇具有一定的催化氧化作用。 相似文献
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The oxidation of carbon nanotubes, C60 and graphite was studied by thermogravimetric (TG) analysis and differential thermal analysis (DTA) technique, and the oxidation kinetic models of three carbon materials studied were analyzed by mechanism-function method. The results indicate that three carbon species adopt different oxidation mechanisms due to their different structures. The oxidation of carbon nanotubes with cylindrical structure follows contracting volume reaction mechanism [R3 mechanism, 1-(1-α)1/3 = kt], indicating that the oxidation of carbon nanotubes takes place from the ends to the center. For graphite with planar sandwich structure, the oxidation starts at the edges initially and gradually moves toward the center, which corresponds to contracting area phase boundary reaction mechanism [R2 mechanism, 1-(1-α)1/2 = kt]. The oxidation of C60 with spherical structure, however, is complex and apparently cannot be illustrated with a single kinetic model. The values of apparent activation energy 相似文献
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碳纳米管/PTFE基复合材料摩擦学性能的研究 总被引:9,自引:0,他引:9
以碳纳米管(CNTs)为填料制备了,PTFE基复合材料,并研究了,该复合材料在干摩擦条件下与不锈钢对摩时的摩擦磨损行为,实验结果表明,CNTs/PTFE复合材料的摩擦系数随着CNTs含量的增加呈降低的趋势,其耐磨性能明显优于纯PTFE,当CNTs的体积分数为15%~20%时,其抗磨性能最好,MSEM观察发现纯PTFE的断面上分布着大量的带状结构,而填充了CNTs后,则未观察到这种带状结构,这说明CNTs有效地抑制了PTFE结构的破坏,对PTFE和CNTs/PTFE复合材料的摩擦表面的SEM观察发现,前者的摩擦表面分布着较明显的犁削和粘着磨损的痕迹,而后者的摩擦表面则平整光滑,这表明以CNTs作为填料可有效地抑制PTFE的磨损。 相似文献
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碳纳米管作为载体在邻硝基甲苯多相催化加氢中的应用 总被引:6,自引:0,他引:6
采用脉冲法进样,用邻硝基甲苯常压下气相加氢生成邻甲基苯胺为探针反应研究了纳米碳管负载镍催化剂的催化性能。分别评价了Ni负载在纳米碳管,活性炭,γ-Al2O3,SiO2上的催化活性,实验结果表明:在实验条件下,碳纳米管负载镍作催化剂的反应物的转化率和产物的选择性分别是80%和1005,转化率分别是二氧化硅负载内化剂的2.36倍,活性炭负载镍催化剂的1.83倍和三氧化二铝负载镍催化剂的1.49倍。 相似文献
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