利用甲醛的亲电性能,对化学气相沉积法(CVD)制备的多壁碳纳米管(MWCNTs)进行羟甲基化,并在此基础上酯化接枝马来酸酐,运用透射电子显微镜(TEM)、红外光谱和Zeta电位仪表征了改性后的MWCNTs的表面结构.TEM结果显示,酯化后的MWCNTs明显增粗,说明表面已附有物质.红外结果表明,羟甲基后的MWCNTs的表面有了羟基和亚甲基,而马来酸酐酯化接枝后的MWCNTs有亚甲基和酯基官能团.光学图像分析表明,经甲醛处理后的MWCNTs在水溶液中的分散性明显提高,而马来酸酐酯化接枝后的MWCNTs在二甲苯中的分散性明显增强.Zeta电位的测试结果表明,甲醛处理过的MWCNTs颗粒在水中。负电荷增多。增强了其在悬浮液在溶液中的稳定性.
The multiply walled carbon nanotubes (MWCNTs) were methylolated using eletrophilicity of formaldehyde and then grafted by maleic anhydride. The MWCNTs could be charactedzed by transmission electron microscope (TEM), IR and Zeta potentiometer. The TEM examination showed that the MWCNTs grafted by maleic anhydride were coated. The IR spectra showed that there were many hydroxyl and methylene groups on the surface of the methylolated MWCNTs, ester and methylene ones on the MWCNTs grafted by maleic anhydride. In addition, the optical microphotography showed that the dispersion of methylolated MWCNTs in water was improved significantly. And then, the dispersion of the grafted MWCNTs in xylene was enhanced remarkably. Zeta potential measurements showed that methylolated MWCNTs in water obtained more negative electricity, the MWCNTs suspension obtained higher dispersibility and stability.