Nanodiamonds could enhance washing detergent efficiency

Tiny pieces of diamond could be used to help improve the effectiveness of washing detergents at lower temperatures, according to new research.

A team from Warwick University has shown that detonation nanodiamonds — particles of diamond around 5nm in diameter created by an explosion process — enhance the abilities of surfactants (the active ingredients in soaps) in water under room temperature.

The scientists found that the diamonds helped the surfactants to remove certain fatty deposits that they otherwise could not cope with at temperatures of between 15ºC and 25ºC, which could allow consumers to clean difficult stains while using less energy.

Although the current cost of adding even tiny particles of diamond to detergents would be unaffordable, the scientists hope the discovery could one day translate into a commercial product, even though the science behind it is not fully understood.

‘What we have is an observation that these 5nm particles do have an unusual effect in conjunction with surfactants,’ lead researcher Dr Andrew Marsh told The Engineer.

‘It does depend on the surfactant that’s used, but that’s good news from a chemist’s point of view because there is the possibility of fine-tuning surface properties and making different compositions in different surfactant.’

The scientists think that nanodiamonds may roughen the surface of stains to improve the surfactants’ abilities to capture and remove particles of crystallised fat, which could also be affected by the diamonds’ surface charge.

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

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

The team’s research paper published in the American Chemical Society journal Applied Materials and Interfaces also noted that the long-term toxicity and other health effects of nanoparticles are still not understood, which may limit the use of nanodiamonds until more research is done.

The research was funded by the Cold Water Cleaning Initiative of the EPSRC and detergent manufacturer Procter & Gamble (P&G).