Diamonds help clothes shine in a different way

Thursday, 28 June 2012 05:57

June 28, 2012

The washing machine has already proven to be one of the more important domestic inventions of the past century, saving people from the massive amounts of time needed to keep clothing clean. However, the devices still impose significant costs of their own in the form of the energy needed to wash clothes at high enough temperature to sufficiently clean certain stains.

Researchers at the University of Warwick, led by associate professor of chemistry Andrew Marsh, along with others at Aston University believe they have discovered a method of dramatically improving the cleaning power of ordinary detergents using a rather unexpected supplement: diamonds.

Cleaning with diamonds

The researchers were not working with discarded wedding rings, however, but rather with extremely fine pieces of carbon known as nanodiamonds. These microscopic diamonds are less than ten-thousandths the diameter of a human hair, measuring around 5 nanometers, and are typically formed through specially tailored explosions.

According to PhysOrg, the group of researchers began investigating the potential these tiny crystals had to improve the cleaning potential of biological detergents with funding from the U.K.'s Engineering and Physical Sciences Research Council and multinational manufacturer Procter & Gamble, which owns several detergent brands.

Cutting the heating bill

The hope was to improve the performance of cold-water detergents by introducing an element that would change the profile of stains, reducing the need for high-heat washing that can damage clothing and increases energy costs.

PhysOrg notes that consumers often wash their clothing as many as 80 times per year at temperatures ranging from 60 to 90 degrees celsius, or roughly between 140 and 194 degrees Fahrenheit.

"We found that the 5 nanometre diamonds changed the way detergents behaved at 25 degrees centigrade (77 degrees Fahrenheit), doubling the amount of fat removed when using one particular commercial detergent molecule," noted Marsh. "Even at temperatures as low as 15 degrees centigrade (59 degrees Fahrenheit), otherwise hard-to-remove fat could be solubilised from a test surface."

Marsh explained to The Engineer that the new process can prove more or less effective depending on the nature of the surfactants in the detergent. However, he notes that this could ultimately prove to be a positive finding, since it opens the possibility that further chemical engineering research could "fine-tune" the detergent to take the best advantage from the process.

"The physical and chemical insight already gained paves the way for future research to explore how this unique behaviour might be exploited in other ways," said Marsh.

High price of diamond dust

There are limitations to the potential for this idea, however. If the idea of putting diamonds into laundry detergent seems like it should be expensive, that's because it most certainly is. The price of diamonds generally is inflated well above the actual rarity of the minerals, but for industrial purposes diamonds can generally be had at a lower price than for jewelry.

However, the nanodiamonds are formed by a very specific process, rather than mined, and this procedure can prove quite expensive.

"You can buy these synthetic nanodiamonds from chemical suppliers for something like £30 a gram," Marsh told The Engineer. "That’s not going to be viable from a laundry powder manufacturer’s point of view."

Nevertheless, the research team hopes that its work could be used to design other kinds of materials that might serve the same purpose at a lower cost.

"... I would emphasise that what we’ve uncovered is some fundamental physical and chemical insight," said Marsh. "The next step is going to be about understanding how that could be translated into a more viable commercial product."