Endowing antifouling properties on metal substrata by creating an artificial barrier layer based on scalable metal oxide nanostructures

Here, by creating different types of artificial barrier layer against bacterial attachment, anti-biofouling properties were endowed on three metallic surfaces - aluminum, stainless steel and titanium. To each metallic surface, a tailored chemical oxidation process was applied to grow scalable oxide structures with an additional appropriate coating, resulting in three different types of anti-biofouling barrier, a thin water film, an air layer and an oil layer. Fluorescence images of the attached bacteria showed that the water layer improved the anti-biofouling performance up to 8-12 h and the air layer up to 12-24 h, comparable with the lifetime of the air layer. In comparison, the oil layer exhibited the best anti-biofouling performance by suppressing the fouled area by < 10% up to 72 h regardless of the substratum type. The present work provides simple, low-cost, scalable strategies to enhance the anti-biofouling performance of industrially important metallic surfaces.