Atomic World - Lotus effect

Atomic world > Lotus effect > Activities

The discovery and understanding the self-cleaning effect of lotus leaves help scientists to develop technologies that mimic Nature. Here are a few examples.

Paint: Dirt sticks easily to ordinary wall paints, leading to possible health problems as microorganisms can grow there. Paints making use of the Lotus effect have been developed commercially. Using these paints, dirt can now be washed off the wall by simply spraying water on to it (Fig. 8). This application will be further discussed in Activity 2.

Clothes: Super-hydrophobic materials are ideal for making raincoat and umbrella. By covering the fabric with a layer of super-hydrophobic material, raincoat can be made waterproofing and air permeable at the same time. In fact, clothes that make use of this principle are now commercially available (Fig. 9).

Windows: Chemicals with the Lotus effect and highly transparent to light can be applied to coating windows, so that windows can be self-cleaned simply by raindrops.


Fig. 8 Self-cleaning effect on paint that makes use of Lotus effect. Photo Courtesy of Sto AG		Fig. 9 A pair of waterproof trousers that make use of Lotus effect.

Identifying leaves with Lotus effect

Go to the market and collect some leaves of vegetables. Try to identify the leaves that have the Lotus effect.

Comparing Lotusan paint and regular paint

Materials
Water sprayers, stain, surface painted with regular paint, surface painted with Lotusan paint (This is a commercially available paint making use of the Lotus effect)

Compare the paints and observe the self-cleaning effect. On Lotusan paint, water beads lay loosely to a painted board and rolls off the board easily by shaking.

Creating a hydrophobic surface on a glass slide

Materials
Two glass slides, candles, dropper, Bunsen burner

Procedure

1.

Coat a thin layer of wax on one of the glass slides by melting the candle.

2.

Since wax naturally is hydrophobic, spherical water droplets will form on the waxed glass slide.

3.

Tilt the glass slide and you will see the droplet roll off much faster than the droplet forms on regular glass slide.