Nature-inspired surface/interface modifications and its applications using catechol/gallol derivatives and amine polymers

Abstract

Catecholamine chemistry is easily found in daily life, such as fruit browning and coffee ringing. Mussel’s adhesion is a representative example using catecholamine chemistry in nature. Mussel can strongly adhere on a variety of surfaces regardless of different properties. Inspired by mussel’s adhesion, polydopamine coating was developed as a material-independent coating and has been applied in various field from biomedicals to energy since 2007. Other than mussel’s adhesion, new adhesive materials on the surface and interface inspired by catechol/gallol-amine chemistry in nature will be introduced in this Ph.D. dissertation.

The first chapter will introduce representative examples of catechol/gallol-amine chemistry in nature, material-independent coatings based on catechol/gallol chemistry, and catechol-conjugated adhesive materials. In the second chapter, we will focus on the importance of cation-$\pi$ interaction on polydopamine formation and the application as superhydrophilic coating using it. The understanding of the mechanism of polydodamine formation is important as a clue to understand the formation process of melanin. The third chapter will deal with a self-healing film mimicking catechol /gallol-amine chemistry at the liquid/air interface found in insect wound healing and fruit browning processes. The self-healing interfacial film based on catechol/gallol-amine chemistry does not require external stimuli or catalyst and exhibits high healing efficiency. In Chapter 4, we will discuss air-curable superglue via hybrid with silica nanoparticles. Silica nanoparticles enhance the adhesion by providing air and the cohesion by the entanglement with polymers. The waterborne gallol amine adhesive exhibits strong adhesiveness without volatile organic compounds. The fifth chapter will discuss lignin-inspired gallol amine hardener for cellulose paper and its application as 3D printing materials. Gallol amine solution can bind to the cellulose fibers and enhance the physical strength as well as the resistance against water and fire via the polymerization, which can be used as 3D printing materials for LOM type.