January_February_2022_AMP_Digital

A D V A N C E D M A T E R I A L S & P R O C E S S E S | J A N U A R Y / F E B R U A R Y 2 0 2 2 4 6 STRESS RELIEF ECOFRIENDLY GLITTER FROM SUSTAINABLE SOURCES A sustainable, nontoxic, vegan, and biodegradable glitter made from cellulose claims to be as sparkly as the original plastic version. Researchers from the University of Cambridge found a way to make the glitter from cellulose nanocrystals, which can bend light in such a way to create vivid colors through a process called structural color. The same phenomenon produces some of the brightest colors in nature—such as those of butterfly wings and peacock feathers—and results in hues which do not fade, even after a century. Cellulose is the main building block of cell walls in plants, fruits, and vegetables. Using self-assembly techniques which allow the cellulose to produce intensely col- ored films, the researchers say their materials could be used to replace the plastic glitter particles and tiny mineral effect pigments which are widely used in cosmetics. In Europe, the cosmetics industry uses about 5500 tons of microplastics every year. The films of cellulose nanocrystals prepared by the team can be made at scale using roll-to-roll processes like those used to make paper from wood pulp, and this is the first time these materials have been fabricated at industrial scale. The results are reported in the journal Nature Materials. www.cam.ac.uk . RESEARCHERS CREATE WORLD’S WHITEST PAINT A white paint created to reflect sunlight away from buildings was named the whitest paint in the 2022 edition of Guinness World Records. Researchers at Purdue University say using this new paint formulation to cover a roof area of about 1000 sq ft could result in a cooling power of 10 kilowatts. Two features make the paint ultra-white: a very high concentration of barium sul- fate–also used in photo paper and cosmetics–and different particle sizes of barium sul- fate in the paint. What wavelength of sunlight each particle scatters depends on its size, so a wider range of particle sizes allows the paint to scatter more of the light spectrum from the sun. The formulation the lab created reflects 98.1% of solar radiation at the same time as emitting infrared heat. Because the paint absorbs less heat from the sun than it emits, a surface coated with this paint is cooled below the surrounding temperature without consuming power. The researchers have partnered with a company to scale up the paint and put it on the market. purdue.edu . IMPROVE YOUR CRICKET GAME WITH A BAMBOO BAT Researchers from Cambridge’s Centre for Natural Material Innovation compared specially made laminated bamboo cricket bats to typical willow bats and found that bamboo is significant- ly stronger. The investigations included microscopic analysis, video capture technology, computer modelling, compression testing, measuring how knocking-in improved surface hardness, and test- ing for vibrations. The study found that bamboo has a strain at failure more than three times greater than willow and was able to hold much higher loads, meaning that bats made with bamboo could be thinner while remaining as strong as willow. This would help batsmen as lighter blades can be swung faster to transfer more energy to the ball. The researchers also found that bamboo is 22% stiffer than wil- low which also increases the speed at which the ball leaves the bat. www.cnmi.org.uk . Vials containing photonic cellulose nano- crystals particles dispersed in three di er- ent solvents: water, water: ethanol, and ethanol. Courtesy of Benjamin Droguet. Xiulin Ruan, a Purdue University profes- sor of mechanical engineering, and his students have created the whitest paint on record. Courtesy of John Underwood/ Purdue University. Co-author Darshil Shah with bamboo cricket bat prototype and section of bamboo. Courtesy of Darshil Shah.