All that glitters is not green. Glitter and shimmery pigments are often made using toxic compounds or microplastics. But a new type of glitter could change that.
This glitter is nontoxic and biodegradable. It is made using cellulose, which is found in plants. In bits of the glitter, cellulose creates tiny structures that reflect specific wavelengths of light. That gives rise to vibrant structural colors.
Such plant-based glitter could make arts and crafts more eco-friendly. It also could be used to make shiny pigments for paints, makeup or packaging. Researchers described the glitter November 11 in Nature Materials.
Their inspiration came from the African plant Pollia condensata. It grows bright, iridescent blue fruits. They’re known as marble berries. In these berries, cellulose fibers reflect light in specific ways to create a metallic blue hue.
“I thought, if the plants can make it, we should be able to make it,” says Silvia Vignolini. She’s a chemist at the University of Cambridge. That’s in England.
She was part of a team that whipped up a watery mixture containing cellulose fibers. Each fiber is like a tiny rod. The team poured the liquid onto a plastic sheet. As the liquid dried into a film, the cellulose fibers settled into structures shaped like spiral staircases. Tweaking the steepness of those staircases changed which wavelengths of light the cellulose structures reflected. That, in turn, changed the color of the film.
Like fairy-tale characters spinning straw into gold, the researchers transformed their plant-based slurry into long, shimmery ribbons. Those ribbons came in a whole rainbow of colors. Once peeled off their plastic platforms, the ribbons could be ground up into glitter.
“You can use any type of cellulose,” Vignolini says. Her team used cellulose from wood pulp. But cellulose is also found in fruit peels. It could also be taken from cotton fibers left over from textile production.
The researchers need to test the environmental impacts of their new glitter. But Vignolini is hopeful that natural materials have a bright future.