A Two-Step Silane Coating Incorporated with Quaternary Ammonium Silane for Mitigation of Microbial Corrosion of Mild Steel

Abstract

Quaternary ammonium compounds have been used as antibacterial materials. However, as they are hydrophilic and produce a positively charged surface, it is challenging to develop a durable antimicrobial coating of such compounds. The objective of this study is to investigate a two-step silane coating incorporated with quaternary ammonium silane for mitigation of microbiologically influenced corrosion (MIC) of mild steel in biotic solution (a marine environment with bacteria). The corrosion resistance was characterized by electrochemical impedance spectroscopy and potentiodynamic polarization tests. The intact silane coating and that pre-exposed to the biotic solution were characterized by attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR). The most probable method (MPN) was used to quantify the active microorganisms attached to the uncoated and silane-coated surfaces. Electrochemical results reveal that the coating thus developed improved the corrosion resistance of steel in the biotic solution. The MPN, FTIR, and scanning electron microscopy suggest a significant decrease in the number of active cells that get attached to the coated surface.