fibre – Lightsources.org

Synthetic fibre triumphs steel

2020/10/062020/10/07

Industrial high-strength fibre has been extensively used in daily lives. In addition to the well-known carbon fibre, “aramid fibre” has become the most comprehensive application and the largest production for the high-strength, flame retardant, and corrosion resistant fibre. Thus strong fibre is considered irreplaceable in fields such as national defense, aerospace, automotive, and energy materials. For flourishing market demand, an annual output of aramid fibre is nearly 100K tons in the word. Only several countries, including the US, Japan, Russia, and South Korean, however, are capable of mass production. Among them, the US and Japan occupy 90% market share.

Developing by DuPont company, “Kevlar” is an aramid fibre with currently the world’s leading high-strength fibre. Their strength is 5 times stronger than steel, with merely 1/5 the density of steel. In fact, the light-weight bullet proof clothing is mostly made by Kevlar.

Read more on the National Synchrotron Radiation Research Center website

Image: Customized “mini wet-spinning machine”. Credit NSRRC

A fast and precise look into fibre-reinforced composites

2019/11/122019/11/18

Researchers at the Paul Scherrer Institute PSI have improved a method for small angle X-ray scattering (SAXS) to such an extent that it can now be used in the development or quality control of novel fibre-reinforced composites.

This means that in the future, such materials can be investigated not only with X-rays from especially powerful sources such as the Swiss Light Source SLS, but also with those from conventional X-ray tubes. The researchers have published their results in the journal Nature Communications.
Novel fibre-reinforced composites are becoming increasingly important as stable and lightweight materials. One example of this type of composite is carbon fibre reinforced polymers (CFRP), which are used in aircraft construction or in the construction of Formula 1 racing cars and sports bicycles. The properties of these materials depend to a large extent on how the tiny fibres are aligned and how they are arranged and embedded in the surrounding material, influencing the mechanical, optical, or electromagnetic behaviour of the composites.

To investigate the fibre’s orientation in such composites, researchers must look inside them. One could use small angle X-ray scattering (SAXS), exploiting the fact that X-rays are scattered when they penetrate matter. The resulting scattering pattern can then be used to obtain information about the interior of a sample and potentially the orientation of the fibres. However, the common SAXS methods have the disadvantage of being quite slow: It can take up to several hours to scan centimetre-sized specimens with the required resolution.

Image: Matias Kagias (left) and Marco Stampanoni in front of the apparatus with which they examined the composites using the newly developed X-ray method. Both hold one of the workpieces that have been X-rayed.
Credit: Paul Scherrer Institute/Mahir Dzambegovic

World’s strongest bio-material outperforms steel and spider silk

2018/05/162018/05/18

Novel method transfers superior nanoscale mechanics to macroscopic fibres

At DESY’s X-ray light source PETRA III, a team led by Swedish researchers has produced the strongest bio-material that has ever been made. The artifical, but bio-degradable cellulose fibres are stronger than steel and even than dragline spider silk, which is usually considered the strongest bio-based material. The team headed by Daniel Söderberg from the KTH Royal Institute of Technology in Stockholm reports the work in the journal ACS Nano of the American Chemical Society.

The ultrastrong material is made of cellulose nanofibres (CNF), the essential building blocks of wood and other plant life. Using a novel production method, the researchers have successfully transferred the unique mechanical properties of these nanofibres to a macroscopic, lightweight material that could be used as an eco-friendly alternative for plastic in airplanes, cars, furniture and other products. “Our new material even has potential for biomedicine since cellulose is not rejected by your body”, explains Söderberg.

The scientists started with commercially available cellulose nanofibres that are just 2 to 5 nanometres in diameter and up to 700 nanometres long. A nanometre (nm) is a millionth of a millimetre. The nanofibres were suspended in water and fed into a small channel, just one millimetre wide and milled in steel. Through two pairs of perpendicular inflows additional deionized water and water with a low pH-value entered the channel from the sides, squeezing the stream of nanofibres together and accelerating it.

Image: The resulting fibre seen with a scanning electron microscope (SEM).
Credit: Nitesh Mittal, KTH Stockholm