Dresden 2014 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 52: Biomaterials and Biopolymers (joint session with BP) II
CPP 52.11: Vortrag
Donnerstag, 3. April 2014, 18:00–18:15, ZEU 222
The influence of topology and thermal backbone fluctuations on sacrificial bonds — •Soran Nabavi1, Matthew J. Harrington2, Oskar Paris1, Peter Fratzl2, and Markus A. Hartmann1 — 1Institute of Physics, Montanuniversität Leoben, Leoben, Austria — 2Max-Planck-Institute of Colloids and Interfaces, Department of Biomaterials, Potsdam, Germany
One strategy to improve the mechanical performance of natural materials is sacrificial bonding that can be found in bone, wood, and in some softer biological materials like silk, mussel byssus threads. Sacrificial bonds (SBs) are reversible bonds which are weaker than the covalent bonds that hold the structure together. Thus, upon loading SBs break before the covalent bonds rupture. The rupture of SBs reveals hidden length providing a very efficient energy dissipation mechanism. Furthermore, SBs can reform after their rupture providing molecular repair and self-healing. We use Monte Caro simulations to examine the influence of topology and SBs density on mechanical properties of single polymeric chains. The influence of SB density, topology and thermal backbone fluctuations on mechanical behavior are investigated by computationally mimicking tensile and cyclic loading test. Increasing the SBs density increases the work to fracture and also the energy dissipation in cyclic loading whereas the topology (determines the position and spacing of peak force) and thermal fluctuations (determine height of SB force) changes the mechanical properties. The results bear important implications for the understanding of natural systems and for the generation of strong and ductile biomimetic polymers.