(Photo: The tube on the left shows the original emulsion, while the one on the right shows the rapid separation of the emulsion into oil and water after a newly developed "switchable" detergent is added. Credit: Annette dexter, University of Queensland)

Researchers have developed Pepfactant®, a biological detergent or surfactant made from peptides which can be "switched on" or "switched off" depending on its intended application, such as between the wash cycle and rinse cycle during clothes washing, in separating oil and water during mining, and as a tool for drug delivery.

For example, in laundry detergents there is a built-in pH change that occurs between the wash and rinse cycles. Pepfactants that are designed to respond to that pH change could be added to the detergent to reduce the rinse time, Dexter noted. During the wash cycle, the pepfactant would be in the "on" position, allowing the detergent to clean soiled clothes. During the rinse cycle when the pH changes, the pepfactant switches "off," allowing the suds to be removed with much less water than conventional detergents.

"Some companies have products in clinical trials that could deliver antibiotics to the eye, which are not water soluble. They are delivering those as an emulsion. So there's something we could do with pepfactants, with the additional angle that we could then have that emulsion respond to the pH of the eye so that it would spread across the eye and not be washed away by the tears."

Compared to conventional surfactants, which cost about $10 per kilogram, biologically synthesized pepfactants are expensive, according to Dexter, about $500 per kilogram.

The paper on this research, has been presented at the ACS National Meeting.

Source: EurekAlert