LAUSR

Abstract The combination of antifouling and biocidal methods is an efficient antimicrobial strategy to alleviate environmental biofouling. Herein, a functional organic/inorganic hybrid coating with integrated terpolymer and hybrid Ag@TA-SiO2 nano spheres was designed and fabricated for antifouling purpose for the first time. The silicon-containing terpolymer (GHM) was fabricated via a simplified free radical co-polymerization process with glycidyl methacrylate (GMA), 2-hydroxyethyl methacrylate (HEMA) and 3-(methacryloxypropyl) trimethoxysilane (MPS). It was expected that the (3-aminopropyl) triethoxysilane (KH550) would become immobilized at the epoxide ring of the GMA and eventually crosslinked, acting as a backbone for the final polymeric coating (PGHMK). Meanwhile, Ag nano-particles were decorated with tannic acid (TA) to have a composite surface structure and loaded with silica (SiO2) to form raspberries. The fabrication of the decorated and loaded antibacterial nano particle Ag@TA-SiO2 was environmental-friendly, high efficiency and low-cost. The PGHMK coating was expected to act as an effective antifouling barrier, and the embedded Ag@TA-SiO2 as a functional biocide carrier to collectively inhibit biofouling. To ensure the designed fabrication processes and the products, the microstructural, compositional, morphological changes of the copolymers and nanoparticles were characterized by means of FT-IR, 1H nuclear magnetic resonance, X-ray photoelectron spectroscopy and atomic force microscopy. The antifouling and bactericidal properties of the composite coatings were also systematically evaluated through measuring the adsorption of protein, growth of bacteria and attachment of microalgae on the coating surface. The results indicated that the coating suppressed 98.6 % of protein adsorption, and its antibacterial efficiency reached 99.1 % and 82.7 % for E. coli and S. aureus, respectively. The coating could also remarkably reduce the attachment of microalgae N. Closterium and Dicrateria zhanjiangensis by 93.5 % and 97.6 %, respectively. It is envisioned that the composite coating may provide a promising antifouling and antibacterial surface for marine engineering structures.