自悬浮定向流法制备纳米铝粉的DSC-TG和XPS分析

Analysis of DSC-TG and XPS on nano-aluminium powders prepared by flow-levitation method

采用自悬浮定向流法制备金属纳米Al粉。用差示扫描量热-热重法(DSC-TG)和X射线光电子能谱(XPS)分析对其热性能进行研究。研究结果表明:在Ar气流中,新纳米铝粉的熔点为649.7℃,熔化焓为3.7kJ/mol,分别比粗晶铝的熔点(660℃)和熔化焓(10.79kJ/mol)低10.3℃和7.09kJ/mol;在N2气流中,从20℃升温到800℃时,新纳米铝粉增重约为33%,熔点为648.8℃。在704℃开始有一个放热效应,终点为747.7℃,放热过程的焓为36.4kJ/mol;在Ar气流中进行热分析前后的新纳米铝粉中未发现Ar元素存在;而在N2气流中进行热分析后的新纳米铝粉残余物中发现有N元素存在,样品表面Al,N和O原子的摩尔比为32.78:11.98:55.24。

Nano-aluminium powders were prepared by flow-levitation method. Properties of nano-aluminium particles were investigated with thermal analysis （DSC-TG） techniques and X-ray photoelectron spectroscopy（XPS）. The results show that melting point and fusion enthalpy of the fresh nano-aluminium powders are 649.7 ℃ and 3.7 kJ/mol in Ar, respectively, which are 10.3℃ and 7.09 kJ/mol lower than those of coarse-grained AI. When heated from 20 ℃ to 780 ℃ in N2 the mass of the fresh nano-aluminium powders increases by about 33%, its melting point appears at 648.8 ℃, exothermic effect occurs from 704 ℃ to 747.7 ℃, and the enthalpy of exothermal process is 36.4 kJ/mol. There is no element of Ar on the surface of the nano-aluminium powders and their slag through thermal analysis in Ar, but element of N is found in their slag through thermal analysis in N2, the mole ratio ofAl, N and O atom is about 32.78：11.98：55.24.