Assessing the antifouling effectiveness of the novel organic coating for adherent species in the seawater of the coastal area of Ha Long City, Quang Ninh Province (Vietnam)

Abstract

This paper presents the results of a 12-month testing period in seawater at Vung Oan, Ha Long City marine area, Quang Ninh Province (Vietnam), assessing the fouling organism’s removal effectiveness of polysiloxane (PS)/Ag-Zn zeolite/Cu2O nanocomposite coatings. This experiment is a substantial base to evaluate impact of Ag-Zn/zeolite and Cu2O nanoparticles (NPs) on growth of bacteria and macro-fouling organisms compared to a control coating without the above additives. The results indicated that the coating loaded with Ag-Zn/zeolite and Cu2O NPs exhibited a lower bacterial count than the coating without biocide additives. Specifically, the bacterial count was 9.6 × 105 for the coating with biocide and 2 × 107 for the coating without biocide. Regarding macro-fouling species, the analysis and identification of organisms attached to the coating samples revealed the presence of three fouling species: Perna viridis, Balanus amphitrite, and Haliclona cinerea. Modiolus barbatus, Nereis sp., and Xanthidae were only observed on surface of the control samples, suggesting that Ag-Zn/zeolite and Cu2O NPs can impede the development of Modiolus barbatus, Nereis sp., and Xanthidae on the coating surface. Furthermore, the average weight of macro-fouling organisms on the coating containing Ag-Zn/zeolite and Cu2O NPs was significantly lower (90 g/sample) than that of the macro-fouling organisms on the control coating (333 g/sample). Notably, one of the three samples with the Ag-Zn/zeolite and Cu2O NPs had the lowest weight of macro-fouling organisms, measuring only 35 g. Based on these findings, it can be concluded that polysiloxane/Ag-Zn/zeolite/Cu2O nanocomposite coatings show promise as antifouling paints for marine work applications.