posted on 2023-04-18, 17:06authored byGhulam Mohd, Kowsar Majid, Saifullah Lone
Wetting has an essential pertinence to surface applications.
The
exemplary water-repelling and self-cleaning surfaces in nature have
stimulated considerable scientific exploration, given their practical
leverage in cleaning window glasses, painted surfaces, fabrics, and
solar cells. Here, we explored the three-tier hierarchical surface
structure of the Trifolium leaf with distinguished
self-cleaning characteristics. The leaf remains fresh, withstands
adverse weather, thrives throughout the year, and self-cleans itself
against mud or dust. Self-cleaning features are attributed to a three-tier
hierarchical synergetic design. The leaf surface is explicated by
an optical microscope, a scanning electron microscope, a three-dimensional
profilometer, and a water contact angle measuring device. Hierarchical
base roughness (i.e., nano-/microscale) comprises a fascinating arrangement,
which imparts a superhydrophobic feature to the surface. As a result,
the contaminants present on the leaf surface are washed with rolling
water droplets. We noticed that self-cleaning is a function of impacting
or rolling droplets, and the rolling mechanism is identified as efficient.
The self-cleaning phenomenon is studied for contaminations of variable
sizes, shapes, and compositions. The contaminations are supplied in
both dry and aqueous mixtures. Furthermore, we examined the self-cleaning
effect of the Trifolium leaf surface by atmospheric
water harvesting. The captured water drops fuse, roll, descend, and
wash away the contaminating particles. The diversity of contaminants
investigated makes this study applicable to different environmental
conditions. And, along with other parallel technologies, this investigation
could be useful for crafting sustainable self-cleaning surfaces for
regions with acute water scarcity.