SURFACE FUNCTIONALIZATION VIA MOLECULAR DESIGN FOR ANTIFOULING AND ANTIMICROBIAL COATINGS

Abstract

Biofouling, the undesired accumulation of living micro- and macro-organisms on material surfaces, has been a persistent problem for centuries. Surface functionalization via molecular design is employed to protect surfaces from biofouling. First, zwitterionic poly(2-methacryloyloxyethyl phosphorylcholine) and cationic polylysine brushes were functionalized on substrates via ‘one-step’ immersion process, to impact antifouling and antimicrobial efficacies. Subsequently, property transition from bactericidal to fouling-releasing was achieved on the poly(L-Arginine methyl ester-methacryloylamide) brush-coated surface in response to hydrolysis treatment. On the other hand, layer-by-layer deposited antifouling and antimicrobial coatings were also developed, viz., polyethylenimine/chitosan-based multilayer coating assembled by host-guest interaction and dextran/chitosan-based self-polishing multilayer coating crosslinked within pH-cleavable imine linkages. The functionalized surfaces exhibited a significantly improved resistance to protein adsorption, bacterial adhesion and microalgal attachment. Thus, these polymer coatings developed in this thesis are potentially useful as environmentally friendly alternatives for combatting biofouling in marine and aquatic environments.