Structurally colored films with superhydrophobicity and wide viewing angles based on bumpy melanin-like particles

Abstract

Abstract Non-iridescent structural colors and lotus effect universally existing in the nature provide a great inspiration for artificially developing angle-independent and high hydrophobic structurally colored films. To this end, a facile strategy is put forward for achieving superhydrophobic structurally colored films with wide viewing angles and high visibility based on bumpy melanin-like polydopamine-coated polystyrene particles. Here, hierarchical and amorphous structures are assembled in a self-driven manner due to particles’ protrusive surfaces. The superhydrophobicity of the structurally colored films, with water contact angle up to 151°, is realized by combining the hierarchical surface roughness with a dip-coating process of polydimethylsiloxane-hexane solution, while angle-independence revealed in the films is ascribed to amorphous arrays. In addition, benefited from an essential light-absorbing property and high refractive index of polydopamine, the visibility of as-prepared colored films is fundamentally enhanced. Moreover, the mechanical robustness of the films is considerably boosted by inletting 3-aminopropyltriethoxysilane. This fabrication strategy might provide an opportunity for promoting the open-air application of structurally colored coatings.