Materials

Lightweight fiber combines strength and toughness

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The fibers are produced via an electrospinning process
University of Bayreuth
The fibers are produced via an electrospinning process
University of Bayreuth
The fibers are heated and then cooled, while being stretched
University of Bayreuth
A microscope image, showing the numerous fibrils within one piece of the fiber
University of Bayreuth
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When it comes to manmade fibers, they can typically either be strong or tough. A new material developed in part by Germany's University of Bayreuth, however, is claimed to be both.

In a nutshell, strength is the ability to withstand force without permanently deforming, while toughness is the ability withstand force without fracturing. Not only does the new type of fiber reportedly combine both qualities, but it's also said to be very lightweight, and fully recyclable.

Each fiber is about the width of a human hair, and it consists of up to 4,000 much smaller fibers made of an industrial polymer known as polyacrylonitrile. These smaller fibers are called fibrils, and they're produced via an electrospinning process. They're adhered together longitudinally using a small amount of poly(ethylene glycol) bisazide.

What results is a single fiber that's made up of many joined fibrils. That fiber is stretched and heated, after which it's left to cool for several hours – still in a stretched state. The finished product is said to possess qualities similar to those of spider silk. A single short length of the fiber, weighing "less than a fruit fly," can be used to repeatedly lift a 30-gram (1-oz) weight without snapping or permanently stretching.

A microscope image, showing the numerous fibrils within one piece of the fiber
University of Bayreuth

It is now hoped that once the technology is developed further, the "multifibrillar polyacrylonitrile fibers" could find use in fields such as textiles, aerospace or medicine.

"We are certain that our research results have opened the door to a new, forward-looking class of materials," says the lead scientist, Prof. Andreas Greiner. "Practical applications on the part of industry can be expected in the near future. In polymer science, our fibers will be able to provide valuable services in the further research and development of high-performance functional materials."

A paper on the research was recently published in the journal Science. Also involved in the study were scientists from Germany's Martin Luther University, RWTH Aachen University, Jülich Research Center, and Fraunhofer Institute for Microstructure of Materials and Systems, along with China's Jiangxi Normal University and Switzerland's ETH Zurich research institute.

Source: University of Bayreuth

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5 comments
KryptonsSon
And this just might be what we've been looking for to build our first space elevator!
EH
Polyacrylonitrile or PAN fibers are also carbonized to make the better sorts of carbon fiber for composites.
Douglas Rogers
This could be very good for making fine thread composite screws and bolts.
neoneuron
Imagine if you could take this strong fiber, turn it into a resin, and make a cousin of fiberglass in a car. Wow!! This thing would be indestructible in an accident or rust!! And flexible too!! Henry Ford made a similar product using industrial hemp with resin. He made a trunk lid out of it. 4 strong men with sledge hammers could not break it. The video used to be on Youtube.
Saigvre
Who and what among us wouldn't be better if they could bake out stretched for 3 hours? Points for that not being a thing normally associated with the (river) coast around Bayreuth. (Wait, Martin Luther University...RWTH Aachen, Juelich Research Center...maybe that's the one, Fraunhofer Inst. for Microstructure of things that take 7 more words, and Jianxi Normal U. Sort of stretchy! And global warming has the riverbank being more bakey (maybe not at Jiangsu Normal U.)