World Bulletin / News Desk
Scientists have found nature's way of creating colour that never fades, a technique they say could replace pigments used in industry with natural plant extracts in products from food colouring to security features in banknotes.
Layers of cellulose that reflect specific wavelengths of light - 'structural colour' found in peacock feathers, scarab beetles and butterflies - make a particularly intense blue in the Pollia condensata plant, scientists say.
Samples of the fruit in plant collections dating back to the 19th century had not lost any shine or intensity, they found.
"By taking inspiration from nature, it is possible to obtain smart multifunctional materials using sustainable routes with abundant and cheap materials like cellulose," said University of Cambridge physicist Silvia Vignolini.
"It is 10 times more intense and bright than any colour achieved with a pigment," said Vignolini, who led the study with plant scientist Beverley Glover.
Although the fruit has no nutritional value, birds were attracted by its bright colour, possibly as a decoration for their nests or to impress mates, helping in seed dispersal.
"This obscure little plant has hit on a fantastic way of making an irresistible, shiny, sparkly, multi-coloured, iridescent signal to every bird in the vicinity, without wasting any of its precious photosynthetic reserves on bird food," said Glover.
And, unlike pigments, structural colour does not fade over time as it is not broken down by absorbing light.
"Edible, cellulose-based nanostructures with structural colour can be used as substitutes for toxic dyes and colorants in food," said Vignolini. The paper industry is already set up to extract and use cellulose and its processes could also be adapted for security labelling or cosmetics, she said.
"Cellulose-based structures have a really strong optical response and are completely inert in the human body," she said.
Another advantage of the technique is that the desired colour can be achieved by adding layers in the structure to reflect different wavelengths, rather than buying new pigment.
Similar research by Peter Vukusic at Exeter University into the structure that creates colour in butterfly wings has spawned a pigment-free photonic make-up from French cosmetics company L'Oreal.
"I saw how brilliant optically some of these structural colours are," Vukusic told Reuters. "Some species collected as far back as the eighteenth century are as bright today as freshly hatched butterflies."
Vukusic said although some car companies, including BMW , have also exploited the phenomenon to produce iridescent paint that changes colour when viewed from different angles, "this is nothing compared to what you see in nature".
He said that if production challenges can be overcome, the abundance of cellulose - the basis of most green plant material - makes it a material with great potential.
The research is published today in the scientific journal Proceedings of the National Academy of Sciences.
Apple denied creating any “back doors” for intelligence agencies.
The fetuses’ heart rates were monitored at 32, 33 and 34 weeks as they listened to a recording of a female stranger recite the rhyme.
On July 23, 2012, the Sun experienced the most powerful in 150 years, NASA revealed on Wednesday.
Tech giant Apple reported Tuesday a 6 percent increase to $37.4 billion in quarterly revenue after selling 35.2 million iPhones.
The total number of online access devices projected to rise to 50 billion in 2020 and 100 billion in 2030.
Tasmania is currently the only Australian state that bans genetically modified food crops and animal feed.
U.S. Magistrate Judge Gabriel Gorenstein said Friday he had authorized a warrant to be served on Google Inc for the emails of an unnamed individual who is the target of a money laundering investigation.
The freighter was loaded with more than 3,660 pounds (1,660 kg) of food, science equipment and supplies for the space station, a $100 billion research laboratory
The remains include two Tyrannosaurus bataar skeletons, a fossilized egg and a well-preserved 'nest' of several Oviraptor skeletons.
The MindRDR software monitors high levels of concentration, allowing users to take photographs and post it online without even having to move.
Angara rockets are a key to President Vladimir Putin's effort to reform a once-pioneering space industry hobbled after years of budget cuts and a brain drain in the 1990s.
It is hoped that by 2040 drones will be able to use 3D printers to print out mini-drones and repair themselves.
Russian Presidnt Vladimir Putin denied he was restricting web freedoms, saying his main concern was protecting children from indecent content.
Producing stem cells has become fast, easy, and inexpensive.
It's believed that a collision of two asteroids out in space caused a shower of meteors to rain down on Earth during the Ordovician Period some 470 million years ago.
Scientists discovered that wild chimps communicate 19 specific messages to one another with a “lexicon” of 66 gestures.