Biomimic modification of graphene oxide

Surface modification of graphene oxide has attracted increasing attention in recent years. In this article, a green, facile and efficient method was developed to modify graphene oxide with polymers via combination of mussel inspired chemistry and Michael addition reaction. Graphite powder was first oxidized and exfoliated into a single layer of slices through a modified Hummers method, then coated with polydopamine, which was formed via self-polymerization of dopamine in alkaline solution. Next, the intermediate (GO-PDA) was grafted by polyacrylic acid, which was synthesized via reversible addition-fragmentation chain transfer polymerization, through Michael addition reaction. The resulting products were characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, transmission electron microscopy and X-ray photoelectron spectrometry. The characterization results indicated the success of adhesion and grafting of PDA and polyacrylic acid, respectively. The resulting products also exhibited sensitivity to pH. Apart from the polymer demonstrated in this work, many other polymers may also be grafted onto graphene oxide through this strategy when different monomers were adopted. Furthermore, this strategy can also be extended to surface modification of many other materials for the versatility of mussel inspired chemistry. It is therefore recommended that the novel strategy developed in this work should be a general strategy for fabrication of various functional nanocomposites, which can exhibit better performance for different applications.