Lotus, the radiantly graceful aquatic plant that has
played a vital role in many religions and cultures is now a source of
inspiration to nanotechnology.
Things of nature are clean by itself. There are no janitors
in the woods, dusting the trees. While people use various cleaning treatments,
nature applies an environmentally benign cleaning strategy. Drops of water on
the lotus leaf shine with a sparkle, washing away the dirt from it more swiftly
than any other plant. Nature has always been a source of positive inspiration
to man. Researchers observed that wax and microscopic bumps on the surface of
the leaf makes it to repel water. Water droplets rolling down from the lotus
leaf collects the dirt particles and small insects on the top of the leaf, and
effectively cleans the surface. Lotus leaves, through a complicated micro-to
nano surface structure, repel dirt, and water. They found the means to
transform nature into technology which gave way for the making of self
cleaning, and soil, & water repellent textiles.
The traditional techniques demonstrated good effects but
were not durable under conditions of intense use. Chemicals were used in the
early 90s to exhibit water repellent character followed by wax later. Chemically
treated fabrics became harsh and also resulted in a discoloration. Furthermore,
there was no wash durability. The new approach has minimized the shortfalls in
a significant way. Self cleaning and super hydrophobic micro to nano structured
surfaces was observed in some plants. A nano-structured surface is created with
super paramagnetic nano particles. This ferromagnetic fibre structuring with
high energy magnetic field coil takes place after the spinneret, when the
spin-melt is in a thermoplastic state, which allows for the stretching of
filament.
Applying the lotus effect to textiles is not easy. The process of coming up with a hydrophobic surface is a challenging job. The material that repels everything has to be made to stick with the fabric. Basic principle of water repellent is the force of surface tension. When water falls over a normal fabric, it spreads over the fabric surface, making it wet. On the contrary, a drop of water on the surface treated fabric will remain as such, and roll down when tilted. The water drop is not absorbed by the fabric. The treated fabric can withstand not only water, but also other liquids such as coffee, tea, red wine, edible oil, ketchup etc.

Lotus effect has foresees a wide variety of beneficial textile applications in suiting, coats, furnishings, trousers, shower curtains, table covers etc. Fluorocarbon based fabrics are used in making sportswear, and industrial workwear. It is suggested that the fabric should be ironed or tumble dried. Heat treatment is required to restore the repellent effect.
This new technology indicates new ventures in the field of smart textiles. A lotus leaf does not collect any dirt, but a string of ground-breaking, and useful innovations.
References:
- Fluorocarbon (water repellant) finish in textiles, Indian Textile Journal, September 2010.
- A new approach optimizes lotus effect of soil repellent textiles, Bangladesh Textile Today, July-August 2010.
- &sec=article&uinfo=<%=server.URLEncode(2945)%>" target="_blank" class="MsoNormal" style="text-align:justify">http://www.indiantextilejournal.com
- &sec=article&uinfo=<%=server.URLEncode(2945)%>" target="_blank" class="MsoNormal" style="text-align:justify">http://www.lotus-effekt.de
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- picsdigger.com
- wired.com
- spray-shop.co.uk