Source: ACSInspired by self-cleaning surfaces found on leaves and elsewhere in nature, a research team from the University of Science and Technology of China has devised a self-cleaning concrete for the construction industry.

To develop the concrete, researchers combined oil, a hydrophobic (or water repellent) silicon polymer called polydimethylsiloxane (PDMS) and an emulsifier, and added the mixture to wet concrete.

Helped by the emulsifier, the oil encapsulated the PDMS so that droplets formed within the mixture. Once the team dried and heated the mixture, the oil evaporated and PDMS pores were formed within the concrete.

The result, according to researchers, was a porous, lightweight, strong, soundproof and heat-insulating material that repels liquid, dust and other materials.

The findings were published in the American Chemical Society's journal ACS Applied Materials and Interfaces.

To demonstrate its self-cleaning properties, the researchers exposed the concrete to a range of liquids including milk, beer, coffee, soy sauce and dye, none of which left stains. Researchers also exposed the material to heat, mechanical grinding and chemicals and the concrete was similarly unaffected.

Although such material has been attempted in the past by adding hydrophobic chemicals to a concrete mixture, earlier efforts often were hampered by the wear and tear of the chemical additive on the concrete, which, over time, weakened the concrete, making the material less than ideal for the construction industry.

Engineers and scientists often find inspiration in nature, including military armor inspired by natural pearls, indestructible clothing and materials inspired by sugar and buoyant material inspired by spiders.