(14h) Present and Future of Bioinspired Phenolic Coatings for Surface and Interfacial Engineering

Polydopamine, a representative phenolic coating introduced by Messersmith Lab in 2007, is a biomimetic coating formed on most surfaces when solutions of dopamine are exposed to oxygen under mildly alkaline conditions. Polydopamine is not only effective in controlling the surface energy of the targeted (i.e., coated) material, but also enables post-modification using nucleophiles such as amines and thiols by forming stable covalent conjugates with residual quinones on the coating. As a result of its accessibility and versatility, polydopamine has been adopted as a powerful and widespread functionalization tool in biomedical, energy, and industrial applications. However, it has been generally accepted that the wear-resistance of the polydopamine is relatively low. For example, mild sonication or even slight physical stress can severely damage the coating. This limits polydopamine-related applications. We truly believe that our next mission is to achieve mechanically improved polydopamine. In this talk, I would like to share our recent progress on this by 'partial graphitization' of polydopamine through blue diode laser annealing. Here, ‘partial graphitization' means that the functional properties of polydopamine still remain intact while the mechanical properties of the polydopamine are increased by having certain portions of the graphitized polydopamine. By adjusting the laser power, we can precisely control the level of graphitization as confirmed by Raman spectroscopy.We believe that our unique approach to overcome the weak abrasion resistance of polydopamine would once again "revolutionize" the polydopamine field by enabling applications where mechanically strong properties are required.