A nascent research has enabled the synthesis of an ultra-white coatings that can be used in cosmetics and for getting brighter coatings and paints. Moreover, these coatings are edible and non-toxic because of which they can also be used in the food and pharmaceutical industries. Other important properties that add to the usefulness of the coatings include lightweight and ultra-thinness. Scales of beetle have played an important role in forging these ultra-white coatings that are found to be 20 times whiter than normal paper. Non-toxic cellulose is used to make these coatings and the structure of beetle scales is mimicked to enhance the whiteness.
Beetles in Nature
The usual way of producing white colors in substances such as creams, paints, and cosmetics is by using pigments. However, the Cyphochilus beetle, used in the current research, do not get their ultra-white coloring from pigments. Instead, these beetles, mostly found in Southeast Asia, exploit a molecule called chitin to forge ultra-white coatings. Chitin has a dense network that effectively scatters light, thus, resulting in the formation of a very thin and white coating. The researchers pointed to the peculiarity of getting ultra-white color as against other colors. They stated that a specific structural pattern gives the varied color arrangement in butterflies, but to produce white color, the structure should be random.
Tuning Opacity and Whiteness
Nano-fibrils were used by the researchers to tune the whiteness and opacity of the final material.
Transparency of the membranes depended on the thinness of the fibers they were made of, and hence, the researchers added thick fibers to make the membranes opaque.