The lotus plant (Nelumbo nucifera) is a very interesting plant. Although it grows in muddy waters, its leaves always appear clean. The lotus effect refers to self-cleaning properties that are a result of ultrahydrophobicity as exhibited by the leaves of Nelumbo.
By using reflection electron microscopy (REM) observation and investigations into the surface have shown that the surface of the leaf has a special, characteristic roughness. Main properties of the surface of the lotus leaf are systematically arranged and water-repellent. Moreover, nano-size wax crystals form three-dimensional structures.
The high surface tension of water causes droplets to assume a nearly spherical shape.Thanks to minimal surface area of sphere, and this shape therefore demands least solid-liquid surface energy. On contact with a surface, adhesion forces result in wetting of the surface.
Thanks to the combination of waxes' water-repellent chemical properties, lotus leaf is extremely non-wettable, a state called ultrahydrophobia or super-hydrophobia. This combination gives it not only super-hydrophobic characteristic but also self-cleaning character.
The first commercial product made in collaboration with industry was a silicone resin house paint which has since become widely used and in which silicon nanoparticles form micro-structured surface. Also, composite materials made up of nanoparticles in a coating matrix make it possible to manufacture the surface structure required for the "Lotus-Effect".
Posted by Direniş ÇAYLI on November 04, 2016
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