Enhancement of biocorrosion resistance of epoxy coating by addition of Ag/Zn exchanged a zeolite

The incorporation of a synthetic zeolite containing biocide cations in epoxy formulations to prevent biofilm formation and the biodegradation processes derived from its presence was studied. Biocidal action of Ag/Zn-exchanged A type zeolite against Pseudomonas aeruginosa, bacteria usually found in fluid containers from the oil refining industry, was determined by microbiological evaluation using molecular biology and traditional cultivation techniques. The minimum inhibitory concentration method (MIC) was adopted to assess the effect of Ag+ 1 and Zn+ 2 impregnated zeolites on microorganism growth. Cell quantification on biofilms detached from epoxy coated steel coupons indicate that P. aeruginosa cells contained in the biofilm significantly decreased as the zeolite percentage in the epoxy formulation was increased. An inhibitory effect of up to seven orders of magnitude was obtained when Ag/Zn-exchanged A zeolite having MIC value about 200 mg·L− 1 was used as additive in epoxy coatings formulations.