Speaker
Prof.
Friedrich Kremer
(Department of Molecular Physics, Leipzig University)
Description
`Spider silk is a high-performance fiber with unique mechanical properties which are currently not met by man-made materials. It consists essentially out of two proteins, major ampullate spidroin1 and spidroin2, having alanine-rich blocks interrupted by glycine-rich sequences. The former assembles to $\beta$-sheeted nanocrystals which are embedded in the amorphous chains of the latter and which are interlinked by a ~ 10 \% fraction of $\textit{prestressed}$ chains. This causes within the fiber a negative inner pressure which is counterbalanced by the matrix surrounding the fibrils and by the outer skin. Wetting of the fiber results in a spontaneous “supercontraction” into the equilibrated state. In the talk a detailed description of this interplay between inner and outer constraints will be discussed based on a variety of complementary experimental methods like polarized, time-resolved FTIR spectroscopy, measurements of the mechanical modulus and micro-X-ray scattering. It enables one to deduce a $\textit{quantitative}$ model describing the macroscopic response in the dependence on the microscopic parameters.`
`References`
1) Papadopoulos, P.; J.Sölter, F. Kremer, Structure-property relationships in major ampullate spider silk as deduced from polarized FTIR spectroscopy, `$\textit{Eur. Phys. J. E}$` `$\textbf{24}$`, 193-199 (2007).
2) Papadopoulos, P., J. Sölter and F. Kremer, Hierarchies in the structural organization of spider silk - a quantitative model, `$\textit{Colloid and Polymer Science}$` `$\textbf{287}$`, Issue 2, 231-236 (2009).
3) Papadopoulos, P., R. Ene, I. Weidner, F. Kremer, Similarities in the structural organization of major and minor ampullate spider silk, `$\textit{Macromol. Rapid. Commun.}$` `$\textbf{30}$`, 851-857 (2009).
4) Ene, R. P. Papadopoulos, F. Kremer, Combined structural model of spider dragline silk, `$\textit{Soft Matter}$` `$\textbf{5}$`, 4568-4574 (2009).
5) Ene, R., P. Papadopoulos, F. Kremer, Partial deuteration probing structural changes in supercontracted spider silk, `$\textit{Polymer}$` `$\textbf{51}$`, 21, 4784-4789 (2010).
6) Spiess, K., R. Ene, C. Keenan, J. Senker, F. Kremer, T. Scheibel, Impact of initial solvent on thermal stability and mechanical properties of recombinant spider silk films, `$\textit{J. Mater. Chem.}$` `$\textbf{21}$`, 13594-13604 (2011).
7) Ene, R., C. Krywka, S.-G. Kang, P. Papadopoulos, M. Burghammer, E. Di Cola, M. Müller, F. Kremer, Structure changes in Nephila dragline: The influence of pressure, `$\textit{Polymer}$` (2012), DOI: 10.1016/j.polymer.2012.09.045.
8) Anton M., W. Kossack, C. Gutsche, R. Figuli (Ene), P. Papadopoulos, J. Ebad-Allah, C. Kuntscher, F. Kremer, Pressure-Dependent FTIR-Spectroscopy on the Counterbalance between External and Internal Constraints in Spider Silk of Nephila pilipes, `$\textit{Macromolecules}$` `$\textbf{46}$`, 4919−4923 (2013).
9) Schneider D., N. Gomopoulos, C.Y. Koh, P. Papadopoulos, F. Kremer, E.L. Thomas, G. Fytas, Nonlinear control of high-frequency phonons in spider silk, `$\textit{Nature Materials}$` (2016), DOI: 10.1038/NMAT4697.
Primary author
Prof.
Friedrich Kremer
(Department of Molecular Physics, Leipzig University)
Co-authors
Dr
Markus Anton
(Department of Molecular Physics, Leipzig University)
Prof.
Periklis Papadopoulos
(Max Planck Institute for Polymer Research, Mainz, Germany)
Dr
Roxana Figuli
(Karlsruhe Institute of Technology, Germany)
Dr
Wilhelm Kossack
(Department of Molecular Physics, Leipzig University)
