Clean clothes and the air in one easy step

U. SHEFFIELD (UK) — A laundry additive that can be washed into clothes so the wearer purifies the air with every step could be available in just two years, researchers say.

Items of clothing need to only be washed once in the additive, which contains microscopic pollution-eating particles of titanium dioxide that grip  fabrics very tightly.  When the particles then come into contact with nitrogen oxides in the air, they react with the pollutants and oxidize them in the fabric.

The nitrogen oxides treated in this way are completely odorless and colorless and pose no pollution hazard as they are removed harmlessly when the item of clothing is next washed, if they haven’t already been dissipated harmlessly in sweat.

The additive, called ‘CatClo,’ itself is also completely harmless and the nanoparticles are unnoticeable from the wearer’s point of view.

One person wearing clothes treated with CatClo would be able to remove around 5g of nitrogen oxides from the air in the course of an average day—roughly the equivalent to the amount produced each day by the average family car.

Nitrogen oxides produced by road vehicle exhausts are a major source of ground-level air pollution in towns and cities, aggravating asthma and other respiratory diseases. Asthma currently affects one in 12 adults and one in 11 children in the UK. As well as the general benefits that would result from people using CatClo, those suffering from respiratory conditions could also, by wearing clothes treated with the additive, give themselves cleaner air to breathe as they move around.

“It’s the action of daylight on the nanoparticles that makes them function in this way,” says Tony Ryan, professor at the University of Sheffield. “The development of the additive is just one of the advances we’re making in the field of photocatalytic materials—materials that, in the presence of light, catalyze chemical reactions. Through CatClo, we aim to turn clothes into a catalytic surface to purify air.

“If thousands of people in a typical town used the additive, the result would be a significant improvement in local air quality,” Ryan says. “This additive creates the potential for community action to deliver a real environmental benefit that could actually help to cut disease and save lives. In Sheffield, for instance, if everyone washed their clothes in the additive, there would be no pollution problem caused by nitrogen oxides at all.

“We’re now working closely with a manufacturer of environmentally friendly cleaning products to commercialize our laundry additive,” Ryan says. “We believe that using the additive in a final rinse with a full washing load could potentially cost as little as 10 pence—a small price to pay for the knowledge that you’re doing something tangible to tackle air pollution and increase the life expectancy of people with respiratory conditions. We’re confident there’s a really big market out there for this product.”

The new additive is the result of collaboration between the University of Sheffield and the London College of Fashion, with initial support from the Engineering and Physical Sciences Research Council.

Source: University of Sheffield