When most tough fibres are stretched to make them thinner, they become brittle. But a group led by Yuris Dzenis at the University of Nebraska–Lincoln has shown that this is not always the case.

The researchers made polyacrylonitrile fibres (pictured) using a technique called electrospinning. As their diameters narrowed to below 250 nanometres, the fibres became tougher and so were less prone to fracture, but did not lose their strength. Nanofibres were up to 10-fold tougher and stronger than the best commercial fibres.

Dzenis suggests that the toughening is possible because the nanofibres are less crystalline than larger fibres. He thinks that the fibres could be used in load-bearing aerospace structures and bulletproof materials.


ACS Nano http://dx.doi.org/10.1021/nn400028p (2013)