Synthesis of Cu-Ag Bimetallic Nanoparticle Hydrosols and Their Superior Antibacterial Performances for Control of Microbial Corrosion by Desulfovibrio Desulfuricans Biofilm

Microbiologically influenced corrosion (MIC) of engineering structures poses significant safety risks, particularly in environments where sulfate-reducing bacteria (SRB) are prevalent. In this study, a highly stable hydrosol with strong antibacterial properties is developed by adsorbing hydrophilic groups of polymer chains onto the Cu-Ag bimetallic nanoparticles (BNPs). The synergistic effects of polyvinylpyrrolidone (PVP) and polyvinyl alcohol (PVA) overcame the incompatibility between the polymer components and nanomaterials, enhancing the dispersion and stability of the Cu-Ag BNP hydrosol. The results demonstrates that the hydrosol exhibited potent antibacterial activities at 50 ppm (w/w), achieving approximately a 5-log reduction for sessile cells after 21 days using retrieved coupons from 3-day pre-culture vials. The hydrosol led to much cleaner X80 coupon surfaces due to biofilm inhibition and MIC mitigation. The weight loss measurements reveals corrosion inhibition efficiencies of 91% and 78% at 50 ppm and 25 ppm, respectively. Additionally, the density functional theory (DFT) modeling reveals that copper regulates silver ion release, enhancing the antibacterial action. While the Cu-Ag BNP hydrosol shows great potential, challenges still exist in scaling its applications, especially in marine and other harsh environmental settings. This research provides a promising platform for developing sustainable bacterial control strategies, suppressing SRB growth.