Question

5. Surface modification is one of the core nanotechnologies. please discuss the strategy to make self-cleaning surface.

Answer 1

Using lotus leaves which are superhydrophobic, when the water fall on the leave it roll off from the surface carrying the impurities along with it.

The systematically arranged water repellent, nano size wax, crystals form three dimensional structures, similar to small nipples, no greater than a few nanometers and micrometers in size.

When combined with the waxes (water repellent chemical properties) these structures make the lotus leaf extremely non wettable, a state called ultra hydrophobia, and they give it it's self cleaning properties. As the gravitational pull between leaf surface and dirt is very slight, even lipophilic impurities such as soot is also washed away.