Green method developed for making artificial spider silk
A team of architects and chemists from the University of Cambridge has designed super-stretchy and strong fibres which are almost entirely composed of water, and could be used to make textiles, sensors and other materials. The fibres, which resemble miniature bungee cords as they can absorb large amounts of energy, are sustainable, non-toxic and can be made at room temperature.
This new method not only improves upon earlier methods of making synthetic spider silk, since it does not require high energy procedures or extensive use of harmful solvents, but it could substantially improve methods of making synthetic fibres of all kinds, since other types of synthetic fibres also rely on high-energy, toxic methods. The results are reported in the journal Proceedings of the National Academy of Sciences.
Spider silk is one of nature's strongest materials, and scientists have been attempting to mimic its properties for a range of applications, with varying degrees of success. "We have yet to fully recreate the elegance with which spiders spin silk," said co-author Dr Darshil Shah from Cambridge's Department of Architecture.
The fibres designed by the Cambridge team are "spun" from a soupy material called a hydrogel, which is 98% water. The remaining 2% of the hydrogel is made of silica and cellulose, both naturally available materials, held together in a network by barrel-shaped molecular "handcuffs" known as cucurbiturils. The chemical interactions between the different components enable long fibres to be pulled from the gel.
The fibres are pulled from the hydrogel, forming long, extremely thin threads -- a few millionths of a metre in diameter. After roughly 30 seconds, the water evaporates, leaving a fibre which is both strong and stretchy.
For more details: - https://www.sciencedaily.com/releases/2017/07/170710161012.htm