Luigi Cassar, Gian Luca Guerrini and team – Self-cleaning concrete
Researchers have created a new type of durable concrete with good heat and sound insulation characteristics, which among other things, it repels various liquids. Flowing over the surface, they clean the material, taking dust particles with them.
There are plenty of examples of self-cleaning surfaces in nature., such as lotus leaves or gecko paws. Scientists have long tried to give concrete similar properties. through hydrophobic materials. However, surface coatings scratched and wear off over time, and additives reduced strength..
A team from the American Chemical Society was looking for an easy way to make aerated concrete with good mechanical and self-cleaning properties..
To do this, the researchers added oil, an emulsifier, and a hydrophobic silicon polymer called polydimethylsiloxane (PDMS). Thanks to the emulsifier, the oil has formed many tiny droplets containing the polymer.
They then dried and heated the concrete so that the oil evaporated and the pores were covered with PDMS. The resulting material was lightweight yet durable. It repels dust particles and various liquids, including milk, beer, soy sauce, coffee and colored water, even when completely immersed in them..
The concrete retained its superhydrophobic properties even after mechanical grinding, heat treatment and chemical attack. In addition, it absorbs sound well and conducts heat poorly, which is important for building materials..
We also previously reported that research Center «Gazprom Neft» introduced a new bituminous material, which binds the components of the asphalt concrete mixture, forming a protective layer on the road surface.
text: Ilya Bauer, photo and video: American Chemical Society