Defouling and cleaning using nanobubbles on stainless steel

Area of Science:

• Materials Science
• Surface Chemistry
• Biotechnology

Background:

• Fouling of stainless steel (SS) surfaces by biomolecules like bovine serum albumin (BSA) is a significant challenge in various industrial and biomedical applications.
• Effective cleaning methods are crucial for maintaining the performance and longevity of SS components in contact with biological media.
• Existing cleaning methods often have limitations in efficiency and may not be suitable for sensitive applications.

Purpose of the Study:

• To investigate the efficacy of electrochemically generated nanobubbles as a cleaning agent for removing adsorbed proteins from stainless steel surfaces.
• To quantify the cleaning efficiency of nanobubbles compared to conventional washing methods.
• To explore the potential of nanobubble technology for preventing biofouling in biomedia systems.

Main Methods:

• Stainless steel surfaces were prepared and exposed to bovine serum albumin (BSA) for overnight adsorption.
• Electrochemical treatment was employed to generate nanobubbles directly on the SS surface, with or without prior BSA adsorption.
• Atomic Force Microscopy (AFM) was used to visualize nanobubble formation and surface changes.
• Radio-labeled BSA was utilized to quantify protein removal by measuring residual radioactivity on the surface after nanobubble treatment and control washes.

Main Results:

• Electrocatalytically generated nanobubbles demonstrated significant protein removal capabilities, removing over 10% of adsorbed BSA per 3-minute treatment.
• Control groups, involving washing with water and electrolyte, removed no more than 3% of the protein per treatment.
• Nanobubbles were successfully generated on SS surfaces, both with and without adsorbed BSA, as confirmed by AFM imaging.

Conclusions:

• Electrochemical nanobubbles are a highly effective cleaning agent for removing protein fouling from stainless steel surfaces.
• This nanobubble-based cleaning method significantly outperforms conventional washing techniques for protein removal.
• The findings suggest that nanobubble technology holds considerable promise for applications involving the cleaning and anti-fouling of conducting surfaces in biological environments.