The anti-soiling performance of highly reflective superhydrophobic nanoparticle-textured mirrors.

The anti-soiling (AS) performance of solar mirrors coated with a highly transparent, superhydrophobic nanoparticle-textured coating has been characterized. The AS coatings were created on the mirror surface by depositing nano-textured silica nanoparticle layers of ∼250 nm thickness using a draw-down coating process, followed by fluorination of the nanoparticles in a molecular vapor deposition process. Highly uniform surface features of the AS-coated mirrors (20 × 30 cm2, no measurable loss in specular reflectance, and water contact angle >165°) provided an outstanding AS performance.