Assessment of marine antifouling property of fluoropolymer nanocomposite coating on steel substrate - A preliminary assay in laboratory

This paper presents the results of immersion assay on antifouling performance of a fluoropolymer nanocomposite coating on the steel substrate using natural seawater medium in laboratory. The fluoropolymer nanocomposite coating was composed in the presence of reinforcement additives, including organically modified titanium dioxide (m-TiO2), organically modified zirconium dioxide nanoparticles ( m-ZrO2) and antifouling agent of Cu2O nanoparticles and fluoropolymer. The ratio of m-TiO2/m-ZrO2/Cu2O was fixed at 2/2/5 wt.% in comparison with the fluoropolymer weight. The immersion test was applied to evaluating the antifouling performance of the nanocomposite coating in the natural seawater and has been carried out in dynamic condition at the room temperature of 30 +/- 0.1 degrees C during 60 days of testing. The change in characteristics of the nanocomposite coating was observed and recorded weekly including contact angle, color of coating and the released Cu ions content. Other characteristics such as infrared spectroscopy, surface morphology, abrasion resistance and adhesion of the nanocomposite coating were analyzed before and after testing. The obtained results showed that Cu ions could release with a low rate from the nanocomposite coating when rising immersion time and the release of Cu ions followed a linear equation. The contact angle and gloss of the coating were slightly reduced during testing period, indicating that the smoothness of the coating surface did not change significantly when immersed in natural seawater. The adhesion and abrasion resistance of the coating were almost unchanged after 60-day testing. In summary, the nanocomposite coating has good antifouling performance when immersion under natural seawater in the laboratory, considering the above specific characteristics, including the synergistic effect of reinforcement fillers (m-TiO2, m-ZrO2 nanoparticles) and antifouling agent (Cu2O nanoparticles) in the polymer matrix. This in-lab experiment in natural seawater medium has confirmed the nanocomposite coating's antifouling performance and facilitated practical deployment.