Back to Search
Start Over
Glass-like dynamics of the strain-induced coil/helix transition on a permanent polymer network.
- Source :
-
Journal of Chemical Physics . 2016, Vol. 144 Issue 6, p1-7. 7p. 1 Diagram, 1 Chart, 6 Graphs. - Publication Year :
- 2016
-
Abstract
- We study the stress response to a step strain of covalently bonded gelatin gels in the temperature range where triple helix reversible crosslink formation is prohibited. We observe slow stress relaxation towards a T-dependent finite asymptotic level. We show that this is assignable to the strain-induced coil → helix transition, previously evidenced by Courty et al. [Proc. Natl. Acad. Sci. U. S. A. 102, 13457 (2005)], of a fraction of the polymer strands. Relaxation proceeds, in a first stage, according to a stretched exponential dynamics, then crosses over to a terminal simple exponential decay. The respective characteristic times TK and Tf exhibit an Arrhenius-like T-dependence with an associated energy E incompatibly larger than the activation barrier height for the isomerisation process which sets the clock for an elementary coil → helix transformation event. We tentatively assign this glass-like slowing down of the dynamics to the long-range couplings due to the mechanical noise generated by the local elementary events in this random elastic medium. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 00219606
- Volume :
- 144
- Issue :
- 6
- Database :
- Academic Search Index
- Journal :
- Journal of Chemical Physics
- Publication Type :
- Academic Journal
- Accession number :
- 113170120
- Full Text :
- https://doi.org/10.1063/1.4941456