Colourants are used universally in industry, from paints and cosmetics to food and textiles, where they play a central role in visually upgrading a product by acting as a gauge for quality, attractiveness, freshness or taste. The pigment industry has long relied on the use of complex synthetic dyes or inorganic particles to produce colours and visual effects (e.g. hues, brightness, shine).
However, there is a growing demand for more natural or environmentally-friendly ways to add colour – especially in food and cosmetic products. Dyes are commonly used to enhance the look of food and food packaging but have long been tainted with controversy, with concerns over toxins and health impacts – to a point where consumers are increasingly scrutinising ingredients for anything that looks unnatural and potentially harmful.
The bio-inspired photonics group, led by Dr Silvia Vignolini, is taking a different direction. By drawing inspiration from nature and exploiting sustainable biomaterials, such as cellulose in this PoC we use cellulose to make a new class of pigments using the concept of structural colours. Such non-fading “structural coloured” pigments are inspired by the epidermis of several coloured plants.
Cellulose is the most abundant biopolymer on the planet and therefore is a truly renewable and sustainable resource. Its natural degradation pathway avoids concerns over bio-accumulation, an area of intense scrutiny as the environmental implications of synthetic micro-plastics becomes more apparent.
Additionally, by removing the dependence on mica, a glittery mineral used in car paint and makeup and whose extraction raises ethical concerns over child labour in illegal mines, cellulose-based photonics has the potential to have significant societal as well as environmental impact. Therefore, the pioneering science undertaken by the bio-inspired photonics group could have far-reaching appeal as they examine new ways to mimic nature’s methods of producing colour.
