Departamento de Física de Polímeros, Elastómeros y Aplicaciones Energéticas, Instituto de Ciencia y Tecnología de Polímeros, CSIC. c/ Juan de la Cierva 3, 28006 Madrid, Spain.
Phys Chem Chem Phys. 2013 Oct 21;15(39):16806-11. doi: 10.1039/c3cp52672k. Epub 2013 Sep 2.
The direct diazotization of the sp(2) carbon network of graphene and multi-walled carbon nanotubes (MWNTs) is one of the many methods employed to introduce functional groups into these nanostructures. Herein, a methodical study on solvent-free diazotization with ethynylaniline in the presence of isoamyl nitrite is reported. Thermogravimetric analysis and UV-visible, infrared and Raman spectroscopies are used to precisely determine the degree of modification, confirm the presence of physisorption and describe the mechanism of elimination of the modifying groups. The results suggest that the same synthetic protocol in both cases leads to a certain degree of covalent modification, whilst a proportion of the modifying groups remains adsorbed to the carbon nanostructure. A higher level of global modification was observed for MWNTs. It was found that the elimination mechanism of the covalently-linked modifiers is identical for both nanostructures and involves two steps; acetylenic-aromatic bond rupture in the modifier followed by modifier-carbon nanostructure cleavage.
将 sp(2) 碳网络的石墨烯和多壁碳纳米管 (MWNTs) 直接重氮化是将官能团引入这些纳米结构的众多方法之一。本文报道了一种在异戊基亚硝酸酯存在下无溶剂乙二胺重氮化的方法。热重分析和紫外可见、红外和拉曼光谱用于精确确定修饰度，确认物理吸附的存在，并描述修饰基团消除的机制。结果表明，在两种情况下，相同的合成方案导致一定程度的共价修饰，而一部分修饰基团仍吸附在碳纳米结构上。MWNTs 的整体修饰程度更高。结果发现，两种纳米结构的共价键修饰剂的消除机制相同，涉及两个步骤；修饰剂中的炔基-芳基键断裂，然后是修饰剂-碳纳米结构的断裂。
