Covalent functionalization of graphene with poly(methyl methacrylate) by atom transfer radical polymerization at room temperature

Graphene was covalently functionalized with phenol groups by a 1,3-dipolar cycloaddition reaction without degrading its electronic properties. Here, these phenols on the functionalized graphene have been further derivatized with 2-bromoisobutyryl bromide resulting in the attachment of atom transfer radical polymerization initiators to the sides of the graphene. These graphene based macroinitiators were used to initiate polymerization of methyl methacrylate at room temperature, which was found to be active and thus resulted in covalent functionalization of graphene with poly(methyl methacrylate). Fourier transform infrared spectroscopy was used to follow the introduction of macroinitiators and poly(methyl methacrylate) chains. The resulting materials were analyzed by differential scanning calorimetry, high resolution transmission and field emission scanning electron microscopy and the solubility properties of the functionalized graphene were found to be significantly improved. All the results showed that graphene can be covalently functionalized with poly(methyl methacrylate) by the proposed approach.