An S2--responsive coating on 70Cu-30Ni alloy for suppressing microbiologically influenced corrosion induced by sulfate-reducing bacteria

To mitigate the microbiologically influenced corrosion (MIC) of 70Cu-30Ni alloy induced by sulfate-reducing bacteria (SRB), a novel and intelligent antibacterial coating with controlled release properties was developed. The coating was constructed by incorporating S 2- -responsive nanocontainers into the epoxy coating. The nanocontainers were prepared by filling the hollow mesoporous silica nanoparticles (HMSNs) with triclosan (TCS), which served as an antibacterial agent, and the subsequent deposition of ZIF-7, acting as the S 2- -responsive gatekeeper. The synthesized nanocontainers were characterized using various techniques, including SEM, TEM, FT-IR, XRD, and XPS. Antibacterial tests against SRB were conducted to assess the antibacterial effect of nanocontainers. UV–vis experiments demonstrated that TCS could be triggered to release from the HMSNs-TCS@ZIF-7 nanocontainers in response to the attack of S 2- . The sustained release of TCS effectively inhibited the SRB adhesion and the released benzimidazole by the decomposition of ZIF-7 acted as corrosion inhibitors, thereby preventing SRB-induced MIC. This study would contribute to the development and design of intelligent responsive coatings with long-term MIC inhibition capabilities.