多壁碳纳米管表面涂层的形成及其抗氧化性  

Surface Coating Formation on the Multi-walled Carbon Nanotubes and Its Oxidation Resistance

作　　者：罗明[1] 李亚伟[1] 金胜利[1] 桑绍柏[1] 赵雷[1] 

机构地区：[1]武汉科技大学耐火材料与高温陶瓷国家重点实验室培育基地,湖北武汉430081

出　　处：《稀有金属材料与工程》2013年第1期135-139,共5页Rare Metal Materials and Engineering

基　　金：湖北省自然科学基金(2008CDB258;2009CDA050);国家自然科学基金(51072143);教育部新世纪优秀人才支持计划(NCET-10-0137)项目

摘　　要：研究以单质硅粉(Si)、金属铝粉和硅粉的混合物(Al+Si)作为2种不同硅源时,在埋碳床中经1000～1500℃处理后多壁碳纳米管(multi-walled carbon nanotubes,MWCNTs)表面涂层的形成及其抗氧化性能的变化。采用X射线衍射仪、高分辨透射电镜及能谱仪和热重-差示扫描量热仪对处理前后的样品进行表征。结果表明:以Si为硅源时,MWCNTs经小于1400℃处理后表面生成了SiC涂层,1500℃处理后大部分MWCNTs蚀变成实心的SiC纳米线;与Si相比,以Al+Si为硅源时相同温度处理后MWCNTs表面涂层的厚度增加,且1500℃处理后MWCNTs并未发生结构蚀变。与原MWCNTs相比,处理后的MWCNTs抗氧化性能提高,且随着涂层厚度的增加而不断提高。非等温动力学进一步表明,原MWCNTs的氧化活化能为157.69kJ/mol,以Si为硅源时1400℃处理后为202.39kJ/mol,而Al+Si为硅源时达到230.70kJ/mol。Coating formation on multi-walled carbon nanotubes （MWCNTs） treated in a coke bed in the temperature range of 1000-1500℃ using silicon powder （Si） and the mixture of aluminum and silicon powders （AI＋Si） as the silicon sources and its oxidation resistance were investigated by means of X-ray diffraction, high resolution transmission electron microscopy equipped with energy dispersive X-ray spectroscopy and thermogravimetric analysis-differential scanning calorimetry. Results show that using Si as a silicon source, SiC coating forms on the surface of MWCNTs after treated below 1400℃. At 1500℃, most of MWCNTs have transformed into solid SiC nanowires Using AI＋Si as a silicon source, the thickness of the coating increases at the same treated temperature compared with Si source. In addition, transformation of MWCNTs is prevented after treated at 1500 ~C. The oxidation resistance of the treated MWCNTs improves compared with the as-received ones, and it gets better with increasing the thickness of the coating. Non-isothermal kinetics shows that oxidation activation energy of the as-received MWCNTs is 157.69 kJ/mol, while they are 202.39 kJ/mol and 230.70 kJ/mol after MWCNTs treated at 1400℃ using Si and AI＋Si as the silicon sources, respectively

关 键 词：多壁碳纳米管 涂层 氧化 非等温动力学 活化能 

分 类 号：TB304[一般工业技术—材料科学与工程]