Cement surface is porous, therefore, can be penetrated by moisture and contaminants. Hydrophobic coatings can be used to keep out stains and fine dust, but they wear off over time.
A team of Chinese researchers has come up with a new technique to give the concrete surface a self-cleaning feature. First, they blended octane (a fatty molecule) and emulsifier with a silicon-based polymer, forming a suspension that contains microscopic droplets. They then applied the mixture to the concrete and allowed droplets to infiltrate its pores. By heating the coating, they removed octane and left behind a durable layer of hydrophobic polymer.
In their tests, the coated concrete exhibited superior hydrophobicity, resisting staining of coffee, milk, beer, and soy sauce. It also has excellent mechanical strength, heat insulation, and sound absorption ability. The surface stayed stain-resistant even after exposure to continuous grinding, burning-temperature air, and chemical erosion.
This research is now published in the journal ACS Applied Materials & Interfaces.
Source: ACS via Youtube