Berlin 2015 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 69: Biomaterials and Biopolymers (joint session CPP, BP)
CPP 69.2: Vortrag
Donnerstag, 19. März 2015, 15:15–15:30, C 264
Mechanical characterization of recombinant spider silk: yarn tensile testing and single fiber deformation via AFM — •Benedikt Neugirg1, Gregor Lang2, Thomas Scheibel2, and Andreas Fery1 — 1Physical Chemistry II, University of Bayreuth — 2Biomaterials, University of Bayreuth
Outstanding mechanical properties combined with biocompatibility render spider silks one of the most promising materials with respect to biomedical applications. Recombinant routes to e.g. dragline silk core proteins of Araneus diadematus provide access to material fabrication at industrially relevant scales. Together with the electrospinning technique, morphologies based on fibrillar structures, from single fiber to nonwovens are readily producible.
In our work, we mechanically characterize recombinant silk yarns and the individual sub-um diameter fibers which the yarns consist of. For this purpose we use macroscopic tensile testing and nanoscopic AFM lateral bending experiments. Furthermore, we investigate the influence of the relative humidity (RH) which is known to have a huge impact on silk mechanics.
We found the recombinant silk to resemble rubber-like properties at higher levels of RH. Enhancing structure crystallinity by post-treatment of the fibers dramatically increases the energy uptake at high RH prior to rupture. In this (physiologically relevant) humidity range, recombinant spider silk can keep up with its natural analog in terms of toughness, the most prominent mechanical characteristic.