Soon, self-cleaning fabrics that digest stains as soon as they occur

London, May 13 : You may soon be able to rid yourself from the tedious job of cleaning clothes, thanks to scientists who are developing a coating of 'live' enzymes that would make clothes digest stains as soon as they occur.

The team led by Ping Wang at the University of Minnesota, St. Paul, US, have demonstrated that they can make plastic films containing active enzymes like those in biological clothes detergents.

The process used is based on one that is used to produce thin, flat plastic products such as CDs, DVDs and flat-screen displays.

The process known as 'spin coating' involves placing a large dollop of a liquid onto a flat surface, which is then rotated at great speed.

This generates powerful centrifugal forces that push the solution towards the surface edges and cause some liquid to evaporate, leaving behind a thin, solid film over the entire surface.

For the present study, the researchers used 10-cm plastic discs as the flat surface and used spin coating to layer four films on top of each other.

The first layer was a thin film of polystyrene altered to chemically bind to enzymes. The second layer was made up of a solution containing a protein-digesting enzyme known as subtilisin Carlsberg, normally used in biological washing powders to remove stains.

The enzymes in the solution naturally bound to the chemical groups displayed on the polystyrene film.

The third layer contained a chemical called glutaraldehyde that created links between enzymes to ensure they are firmly attached to the plastic. The fourth and the final layer was also made of subtilisin Carlsberg.

The tests demonstrated that nothing short of burning or harsh chemical treatments could affect the enzymes.

"The bonding between the enzyme and the polymer coating is as strong as the chemical bonds that are responsible for the integrity of plastics," New Scientist quoted Wang, as saying.

The study shows that coating such a film into fabric could allow it to start digesting stains as soon as they occurred, making it anti-bacterial by attacking proteins on the outside of the cells.

"Our preliminary results showed that enzymes can be spin-coated onto any pre-prepared plastic structures and, beyond that, probably inorganic structures such as metals and ceramics," said Wang.

Wang also hopes that such enzyme-coated materials could have a wide range of uses, including self-healing materials or protective suits able to digest chemical or biological hazards.

ANI