Spider-silks and Supertough Fibers

Spider silks is the collective name for a family of seven different fibers by one spider for web forming, its living and reproduction.  They are spun by spinnerets in its abdomen with protein dope secreted from its individual spider glands. These seven fibers serve different functions in the web construction for the whole life of the spider. Each fiber has its own gene sequence for amino-acid repeating motifs and its termini structure, which endows the diversity of protein structures with a wide array of extraordinary properties and purposeful uses.  One of the most outstanding features of spider silks is their toughness: they can be tougher than almost all other materials in the world and thus are considered ideal materials by scientists and the industry. Although there have been tremendous attempts to prepare fibers from genetically engineered spider-silk proteins, it is still a very large challenge to artificially produce materials with a very high fracture energy, not to mention the high scaling-up requirements because of the extremely low productivity and high cost levels. Here, a facile spider-silk-mimicking strategy is first reported for preparing scalable supertough fibers using the chemical synthesis route. By mimicking the structure and properties of spider silk, a  pseudoprotein polymer with β-sheet and α-helix and random coil structure  has been synthesized and a supertough fiber was made by dry spinning. The toughness is (~387 MJ m^-3) of the fiber is more than twice the reported value of common spider dragline silk and comparable to the toughest spider silk, the aciniform silk of Argiope trifasciata. The process opens up a very promising avenue for obtaining excellent spider fibers. The talk will give an review on the progress on achieving toughest fibers in the world.