Scientists dipped plain, white T-shirts that were cut into thin strips into a boron solution. The strips were later removed from the solution and heated in an oven. The heat changed the cotton fibers into carbon fibers, which reacted with the boron solution and produced boron carbide.
The result was a fabric that’s lightweight but tougher and stiffer than the original T-shirt, yet flexible enough that it can be bent. That flexibility is an improvement over the heavy boron-carbide plates used in bulletproof vests and body armor.
“The currently used boron-carbide bulk material is brittle,” said Dr. Xiaodong Li, from the USC College of Engineering and Computing Advanced Materials. “The boron-carbide nanowires we synthesized keep the same strength and stiffness of the bulk boron carbide but have super-elasticity. They are not only lightweight but also flexible. We should be able to fabricate much tougher body armors using this new technique. It could even be used to produce lightweight, fuel-efficient cars and aircrafts.”
The resulting boron-carbide fabric can also block almost all ultraviolet rays, researchers say.
Citation: Tao et al., 'B4C-Nanowires/Carbon-Microfiber Hybrid Structures and Composites from Cotton T-shirts', Advanced Material, March 2010; doi:10.1002/adma.200903071