Super strong nanofibres created by US team

"Our discovery adds a new material class to the very select current family of materials with demonstrated simultaneously high strength and toughness," said Yuris Dzenis, a professor of Mechanical and Materials Engineering at the University of Nebraska-Lincoln. "Whatever is made of composites can benefit from our nanofibres," Dzenis and his team began by developed an ultra thin polyacrilonitrile nanofibre, a type of synthetic polymer related to acrylic, using a technique called electrospinning. The process involves applying high voltage to a polymer solution until a small jet of liquid ejects, resulting in a continuous length of nanofibre. The researchers discovered that by making the nanofibre thinner than had been done before, it became not only stronger, as was expected, but also tougher. Dzenis believes the toughness comes from the nanofibres' low crystallinity. This means that it has many areas that are structurally unorganised. These amorphous regions allow the molecular chains to slip around more, giving them the ability to absorb more energy. Most advanced fibres have fewer amorphous regions, so they break relatively easily. In an airplane, which uses many composite materials, an abrupt break could cause a catastrophic crash. To compensate, engineers use more material, which makes them heavier. "If structural materials were tougher, one could make products more lightweight and still be very safe," Dzenis concluded.