A research group from Chiba University in Japan developed a new coating that combines structural color with superhydrophobic properties using melanin-based particles. The technology provides vibrant color without traditional pigments and offers water repellency and self-cleaning performance, marking a potential advance in durable surface coatings.

The structural color effect is created through microscopic arrangements of melanin particles, mimicking natural examples such as peacock feathers. A surface modification process involving polydopamine and hydrophobic octadecyl groups enables high water repellency without the use of fluorinated compounds.

The coatings demonstrated contact angles over 160 degrees and maintained color integrity from multiple viewing angles. Researchers confirmed hydrophobicity using time-domain nuclear magnetic resonance (TD-NMR) and noted that application takes only minutes using simple dispersion in hexane.

The findings, published in Macromolecular Reaction Engineering, suggest applications for the coatings in outdoor surfaces, wallpaper, and other functional or decorative uses. Future research will focus on enhancing durability and adhesion to expand practical use cases.

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Journal reference: DOI: 10.1002/mren.202400040