Ultrastructures and Mechanics of Annealed Nephila clavipes Major Ampullate Silk

Journal Article · 30 January 2020 · Biomacromolecules

DOI: https://doi.org/10.1021/acs.biomac.9b01615 · OSTI ID:1661638

Dugger, Thomas W. ^[1]; Sarkar, Sourangsu ^[1]; Correa-Garhwal, Sandra M. ^[1]; Zhernenkov, Mikhail  ^[2]; Zhang, Yugang ^[2]; Kolhatkar, Gitanjali  ^[3]; Mohan, Ramya ^[1]; Cruz, Luz ^[1]; Lubio, Aura D. ^[3]; Ruediger, Andreas ^[3]; Hayashi, Cheryl Y. ^[4]; Uhrich, Kathryn E.  ^[1]; Kisailus, David J.  ^[1]

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1. Univ. of California, Riverside, CA (United States)
2. Brookhaven National Lab. (BNL), Upton, NY (United States). National Synchrotron Light Source II (NSLS-II)
3. Univ. of Quebec, Varennes, QC (Canada)
4. Univ. of California, Riverside, CA (United States); American Museum of Natural History (AMNH), New York, NY (United States)

The semicrystalline protein structure and impressive mechanical properties of major ampullate (MA) spider silk make it a promising natural alternative to polyacrylonitrile (PAN) fibers for carbon fiber manufacture. However, when annealed using a similar procedure to carbon fiber production, the tensile strength and Young’s modulus of MA silk decrease. Despite this, MA silk fibers annealed at 600 °C remain stronger and tougher than similarly annealed PAN but have a lower Young’s modulus. Although MA silk and PAN graphitize to similar extents, annealing disrupts the hydrogen bonding that controls crystal alignment within MA silk. Consequently, unaligned graphite crystals form in annealed MA silk, causing it to weaken, while graphite crystals in PAN maintain alignment along the fiber axis, strengthening the fibers. Finally, these shortcomings of spider silk when annealed provide insights into the selection and design of future alternative carbon fiber precursors.

• Research Organization: Brookhaven National Laboratory (BNL), Upton, NY (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES)
• Grant/Contract Number: SC0012704
• OSTI ID: 1661638
• Report Number(s): BNL-216380-2020-JAAM
• Journal Information: Biomacromolecules, Journal Name: Biomacromolecules Journal Issue: 3 Vol. 21; ISSN 1525-7797
• Publisher: American Chemical SocietyCopyright Statement
• Country of Publication: United States
• Language: English