Maroc - TIMBERBIZ.COM.AU - A La Une - 07/Aug 00:36

Super black wood

Researchers at the University of British Columbia’s Faculty of Forestry have made an extraordinary discovery: a new super-black material that absorbs almost all light, named Nxylon. This accidental breakthrough holds promising applications in fields such as fine jewellery, solar cells, and precision optical devices. Source: Timberbiz Dr Philip Evans and PhD student Kenny Cheng initially aimed to make wood more water-repellent using high-energy plasma, mimicking the lotus leaf effect. However, when they applied this technique to the cut ends of wood cells, the surfaces turned extremely black. Collaborations with Texas A&M University’s astronomy and physics department confirmed that this new material reflected less than one percent of visible light, absorbing almost all the light that struck it. Rather than overlooking this unexpected result, the UBC team pivoted their research focus to developing super-black materials, contributing a novel approach to the ongoing search for the darkest materials on Earth. “Ultra-black or super-black material can absorb more than 99% of the light that strikes it – significantly more than normal black paint, which absorbs about 97.5% of light,” explained Dr Evans, a professor in the Faculty of Forestry and BC Leadership Chair in Advanced Forest Products Manufacturing Technology. Super-black materials have significant demand in astronomy, where ultra-black coatings on devices help reduce stray light and improve image clarity. These materials also have the potential to enhance the efficiency of solar cells and are used in art pieces, luxury consumer items like watches, and in coating solar cells. The researchers have developed prototype commercial products using Nxylon, initially focusing on watches and jewellery, with plans to explore other commercial applications in the future. The team named their discovery Nxylon (niks-uh-lon), after Nyx, the Greek goddess of the night, and xylon, the Greek word for wood. Unlike most super-black materials that rely on coatings or veneers, Nxylon remains black even when coated with an alloy (such as gold-vanadium) due to its structure, which inherently prevents light from escaping rather than depending on black pigments. Plasma etching creates a low-density surface with large gaps between the wood’s pores, forming a network of hollow fibres and tapered columns. These tiny structures, combined with the wood’s natural composition, absorb and trap light, giving the material its super-black appearance. “Nxylon’s composition combines the benefits of natural materials with advanced structural features, making it lightweight, stiff, and durable,” adds Dr. Evans. The UBC team envisions Nxylon potentially replacing expensive and rare black woods like ebony and rosewood and being used in jewelry pieces where the black gemstone onyx would typically be used. Made from basswood, a tree widely found in North America and valued for hand carving, boxes, shutters, and musical instruments, Nxylon can also utilize other types of wood. Dr. Evans and his colleagues plan to launch a start-up, Nxylon Corporation of Canada, to develop practical applications in collaboration with jewelers, artists, and tech product designers. They also plan to test other low-to-medium density hardwoods for plasma modification to produce larger super-black wood samples suitable for non-reflective ceiling and wall tiles. “Nxylon can be made from sustainable and renewable materials widely found in B.C. and North America, leading to new applications for wood. The wood industry in BC is often seen as a sunset industry focused on commodity products our research demonstrates its untapped potential,” said Dr. Evans. Other researchers who contributed to this work include Vickie Ma, Dengcheng Feng, and Sara Xu.