Researchers at the Indian Institute of Technology (IIT) Hyderabad have developed a cheap waterproofing material by coating fly ash.
Fly ash is a waste by-product from coal-based thermal power plants, with stearic acid, which is a surfactant.
While fly ash is extremely water-loving (hydrophilic), it turns into a highly water-repelling surface once coated with stearic acid.
Fly ash varies in size from 100 nanometres to a few microns and can thus provide surfaces with different roughness based on the size of the particles chosen.
Stearic acid-coated fly ash surface can be made to behave like rose petals or lotus leaves.