There are any number of measures out there today to help reduce the carbon footprint of buildings. But ever heard of a smog-eating, self-cleaning building? Sounds intriguing. US-based Aluminium company Alcoa has just unveiled its oil-coated architectural panel that it says could revolutionise sustainable building solutions.
So how exactly does it work? By applying a titanium coating (called EcoClean) to Alcoa’s aluminium composite (called Reynobond). The key is in the titanium coating, which Alcoa describes as a “pro-active coating powered by free radicals”. When sunlight strikes a particle of titanium dioxide, explains Alcoa, electrons within the particle become excited, creating a higher state of energy within the electrons. The energised electrons transfer energy to water in the air and form free radicals, which act as powerful oxidizers that can attack any organic material either on the panel’s surface or floating near it.
Got it? There’s more. One of the most common forms of organic matter found on buildings is nitrogen oxide (NOx), a primary component of smog. As well as being a pollutant, it also makes building appear dirty. When NOx particles float near the surface of a titanium coated panel, they are attacked by free radicals generated from the titanium dioxide reacting with water and oxygen in the air. These free radicals then go onto oxidize the NOx molecules, converting them to a harmless nitrate.
According to Alcoa, 10,000 square feet of the EcoClean and Renobond panels has the equivalent air cleansing capabilities of 80 trees.
“Alcoa is committed to innovating sustainable solutions for today and tomorrow,” says Craig Belnap, president of Alcoa Architectural Products. “That passion is a driving force behind our architectural business. Our R&D in science and technology is creating new ways for aluminum building products to meet green building standards—from the use of natural cleaning products like Reynobond with EcoClean, to advanced façade solutions that help reduce CO2 emissions and energy consumption.”
The company worked together with Japanese manufacturer TOTO, apparently employing a team of more than 50 scientists and engineers to develop the product. It estimates the self-cleaning panels could save from a third to a half of building maintenance costs.