Superhydrophobic treatment and self-sealing film coating based on catecholamine surface chemistry

Abstract

Catechol functional groups can easily be found in thread of marine mussel that sticks to many kinds of surfaces. The catechol moiety can interact with various functional groups and make bond with them, and this is why the mussel thread is able to stick to numerous substrates. Lots of researches have been accomplished using catechol-derivatives for coatings on various substrates and further treatments, including surface functionalization, cell adhesion, and energy application. Especially, these secondary treatments have established notable achievements in superhydrophobic treatments. A hierarchical micro/nanostructure necessary to achieve the superhydrophobicity can easily be obtained on catechol-functionalized surfaces, thanks to the catechol moieties interacting with microstructure precursors. Catechol-derived molecules can also be found in insect cuticle, playing a role in wound-healing process of insect exoskeleton. The molecule interacts with protein in the insect and makes cross-linked film, which spontaneously heals the wound on the insect cuticle. This recovering mechanism can be utilized in new-type self-sealing materials. In this thesis, we demonstrate surface-independent superhydrophobic treatment and long-lasting, stimuli-free self-sealing film, based on these properties of catechol-based molecules. We applied the superhydrophobic treatment to flexible substrate for application to control the flow of water and its direction, and fabricated multiple-electrospraying system for spray of water. Also, we annealed the self-sealing film to give electrical conductivity on it, and utilized the annealed film to recover macroscopic damage on graphene.