An obscure species of beetle has shown how brilliant white paper could be produced in a completely new way. A team from Imerys Minerals Ltd. and the University of Exeter has taken inspiration from the shell of the Cyphochilus beetle to understand how to produce a new kind of white coating for paper.
The Cyphochilus beetle has a highly unusual brilliant white shell. In 2007, research by the University of Exeter and Imerys Minerals Ltd., published in leading journal Science, revealed how the beetle produced its brilliant whiteness using a unique surface structure. Native to south-east Asia, it is believed that the beetle's whiteness evolved to mimic local white fungi as a form of camouflage.
New research, now published in the journal Applied Optics, shows how some of the beetle's shell structure can be mimicked to produce coatings for white paper.
At one 200th of a millimetre thick, the beetle's scales are ten times thinner than a human hair. Good quality white paper is coated with a mixture of white mineral particles such as calcium carbonate and kaolin. Using conventional production methods, industrial mineral coatings for high quality paper would need to be twice as thick as the beetle shell to be as white.
The team has now shown that through careful mineral selection and processing, it is possible to mimic some of the structure of the white beetle's shell to produce an enhanced bright white coating for paper. This higher performance could result in lighter weight paper with a very high degree of whiteness. Lighter paper would also reduce transportation costs, simultaneously reducing the economic and environmental cost of manufacture.
Colour in both nature and technology can be produced by pigmentation or by very regularly arranged layers or structures. Whiteness, however, is created through a random structure, which produces 'scattering' of all colours simultaneously. Studies of the beetle's body, hea
|Contact: Sarah Hoyle|
University of Exeter