Development of Functional Materials Inspired by Marine Organisms

Abstract

In recent years, non-biofouling surface has been interested for applications in medical devices, biosensor, and marine equipments. Various materials including polysaccharides, polyethylene glycol (PEG), and zwitterionic polymers have been investigated to generate non-biofouling surfaces. Although the above-mentioned materials have been successfully implemented for non-biofouling surface preparation, complicated chemical reactions and material dependent properties were considered to be significant drawbacks. To solve the problem, we developed a facile and material-independent surface coating method using a mussel-inspired functional material, polydopamine. Combination of mussel-inspired polydopamine and non-biofouling materials enabled the introduction of non-biofouling property onto the various surfaces. In chapter 1, we reported that emulating the properties of the mussel byssus cuticle provides an important platform for developing reversible layer-by-layer (LbL) deposition, an advanced technique for surface modification. LbL films were constructed on solid substrates by sequential immersion of substrates into solutions containing iron (III) and catecholic compounds. In chapter 2, we reported a facile and versatile approach to the formation of marine antifouling surface coatings. The approach consists of a combined coating of polydopamine and tannic acid and subsequent immobilization of PEG on solid substrates. TA coating of a polydopamine-coated surface was carried out using iron (III) coordination chemistry, and PEG was immobilized on the TA-coated surface via hydrogen bond formation. Stainless steel and nylon were successfully modified by this approach, and the resulting substrates were used for marine antifouling applications, in which diatom adhesion was significantly inhibited. In the last chapter, we synthesized a catechol-conjugated alginate (Alg-C) to construct anti-bacterial nanofilms. The Alg-C nanofilm was formed on the polydopamine-coated surface via iron (III) coordination reaction, and the resulting surface showed excellent resistance against E. coli adhesion, implying the anti-bacterial property of the surface.