Studies on Biocide Encapsulated Zeolite-epoxy Nano Hybrid Coatings on Mild Steel

The present study aims at the fabrication of nano-hybrid coatings using diglycidyl ethers of bisphenol-A (DGEBA) as matrix material modified with effective low cost as well as less toxic antifoulants viz., benzoic acid (BA) and sodium benzoate (SB), which are encapsulated into nanozeolite containers as reinforcing materials that could be utilized for marine coatings. These two antifoulants were incorporated into epoxy antifouling (AF) coatings separately in the amount of (1, 3, 5, 7 and 10 wt. %) to investigate their corrosion resistant behaviour and antifouling capabilities. Corrosion rate of 3 wt. % SB incorporated epoxy AF coating was determined to be much lower than that of 3 wt. % BA incorporated epoxy AF coating. A direct relationship between the corrosion rate, antifouling nature, antibacterial behaviour and toxicity was observed by electrochemical impedance spectroscopy, salt spray test, static immersion study, antibacterial test and acute toxicity tests. The SB encapsulated coating with 3 wt. % loading exhibits enhanced antifouling and corrosion resistance performance, while AF coatings contains 5 wt. % loading of BA showed a marked reduction in fouling attachment than other coating compositions.