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arXiv · 0810.4082

From thermally activated to viscosity controlled fracture of biopolymer hydrogels

T. Baumberger·O. Ronsin
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Abstract

We report on rate-dependent fracture energy measurements over three decades of steady crack velocities in alginate and gelatin hydrogels. We evidence that, irrespective of gel thermo-reversibility, thermally activated "unzipping" of the non-covalent cross-link zones results in slow crack propagation, prevaling against the toughening effect of viscous solvent drag during chain pull-out, which becomes efficient above a few mm.s$^{-1}$. We extend a previous model [Baumberger {\it et al.} Nature Materials, {\bf 5}, 552 (2006)] to account for both mechanisms, and estimate the microscopic unzipping rates.

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T. Baumberger, O. Ronsin. 2008-10-22. From thermally activated to viscosity controlled fracture of biopolymer hydrogels. https://doi.org/10.1063/1.3078267

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