Researchers investigated the anti-soiling (AS) performance of highly reflective, superhydrophilic (SPH, 0° water contact angle) and superhydrophobic (SP, >165° water contact angle)coated mirrors. A simple one-step nanotextured silica nanoparticle coating on a mirror exhibited SPH properties associated with hydrophilic rough surfaces while another mirror surface post-functionalized with low-surface-energy ligand molecules displayed SP behavior.
ıt was found in daily degradation in solar reflectance induced by dust accumulation under outdoor field testing that the SPH- and SP-coated mirrors, compared with an uncoated mirror, maintained higher solar reflectance, which was associated with the designed self-cleaning behavior and natural cleaning.
However, it was reveleade over the long term that dust-moisture cementation—evidenced by organic hard water stains on the mirror—initiated unrecoverable reflectance loss on the SP-coated mirror after 3 months, whereas the SPH-coated mirror maintained higher reflectance for 7.5 months. Considering fabrication costs and maintenance, SPH-coated nanotextured mirrors offer potential benefits for application in solar energy harvesting.
Journal reference: Nanoscale Advances
Provided by: © Royal Society of Chemistry 2019