Improving long-term control of microbial corrosion and biofouling by a novel insoluble antimicrobial enhancer

Tetramethylphosphoric acid, guanidine dodecyl monohydrochloride, and sodium molybdate can be easily synthesized into an antibacterial material (TNG) that is almost insoluble in water. However, TNG still has limitations when used directly as a protective layer on metal surfaces. Nevertheless, TNG can serve as a coating enhancer, significantly improving the hydrophobicity of the coating while maintaining its hardness. TNG enhances the corrosion resistance of epoxy coatings against microbial attack caused by sulfate reducing bacteria (SRB) biofilm. The epoxy coating enhanced by TNG effectively inhibited the formation of SRB biofilm and kill a few sessile cells. Compared to coatings not enhanced with TNG, the corrosion current density was reduced by 3460 times. A dynamic corrosion test conducted over 9 months in the Yangtze River basin demonstrated that the stable presence of TNG in the epoxy coating achieves long-term inhibition of biofouling in real-world environments.