Styrene-butadiene-styrene-based nanocomposites as self-healable antibacterial coatings

This study presents the development of self-healing antibacterial polymeric composite coatings to minimize infection risks and ensure adaptability for large spaces by using readily available materials and scalable, efficient fabrication techniques. These coatings were prepared by incorporating 300–400 nm solid silica particles capped with a polydopamine layer of ~40 nm thickness and decorated with silver nanoparticles within a styrene-butadiene-styrene matrix. The aqueous dispersion of filler particles upon exposure to near-infrared 808 nm light exhibits a temperature increase of ~15 °C caused by the photothermal activity of polydopamine in synergy with silver nanoparticles. This photothermal activity of fillers helps to achieve the complete healing of micron-sized scratches of nanocomposite films with light intensities as low as 1.19 W/cm² over 10 min (total energy fluence of 716 J/cm²), demonstrating promising results for real-world applications. Additionally, the coatings exhibit significant enhancement in antibacterial activity, reducing bacterial colony counts by >99.9 %. These findings underscore the potential of such coatings to reduce the risk of pathogenic infections in clinical settings while offering sustainable and eco-friendly solutions.