Nanobubble-Induced Oxygen Gradients Control Corrosion Mode and Bacterial Adhesion on Martensitic Stainless Steel

These corrosion patterns directly translated into distinct biofilm structures: patchy biofilms formed on oxygen-treated surfaces, whereas nitrogen nanobubbles promoted a uniform biofilm. These observations are consistent with nanobubble-driven oxygen transport at the interface. We propose that an oxygen concentration gradient along the length of the steel coupon promotes differential aeration cells and pitting corrosion, whereas nitrogen nanobubbles deoxygenate the system, destabilizing the passive layer and leading to uniform corrosion.

Consistent qualitative observations from both crystal-violet and DAPI staining reveal a strong coupling between nanobubble-mediated oxygen gradients, corrosion morphology, and microbial colonization. These findings highlight nanobubbles as a simple tool for controlling interfacial electrochemical processes and biofilm formation.