Читать книгу Metal Oxide Nanocomposites - Группа авторов - Страница 84

The covalent functionalization in graphene is commonly headed by chemical oxidation of the graphite with the effect of strong acids and oxidants to acquire oxygen-rich functional moieties that assist as pioneers for the chelation of organic molecules. As a detailed synthesis of GO outcomes in extremely functionalized oxygen surface moieties, thereby reaching the C/O fraction of 2:1 [46]. The generic reactions of covalent functionalization in graphene comprises of two methods:

 • The covalent bond amongst C=C moieties of graphene and free radicals

 • Covalent bonds between –O moieties of GO and functional surface moieties of organic molecules.

Like as the covalent functionalization of GO by imidazolium has been reported in the literature. Here, it is witnessed the covalent chelation via amide bonds between the 1-(3-aminopropyl)-imidazole and carboxylic moieties of GO. Consequently, the transformation was observed in the heterocyclic ring employing N-methylation to its ionic imidazolium derivatives [47]. Similarly, the covalent functionalization is witnessed between GO and 3-aminopropyl triethoxysilane (APTS) by epoxy moieties. The chemical reaction comprised of silicon-functionalized GO (Si−GO), which was uniformly amalgamated with silica matrix and excess of APTS to endure covalent chelation [48].