From thermally activated to viscosity controlled fracture of biopolymer hydrogels
From thermally activated to viscosity controlled fracture of biopolymer hydrogels
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DOI：
10.1063/1.3078267
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发表时间：
2009-02-14
影响因子：
4.4
通讯作者：
Ronsin, O.
中科院分区：
文献类型：
--
作者：
Baumberger, T.;Ronsin, O.
我们报告了在海藻酸盐和明胶水凝胶的稳定裂缝速度超过三十年的速率依赖的断裂能测量。我们证明，无论凝胶的热可逆性如何，热激活的非共价交联区域的“解压缩”导致缓慢的裂纹扩展，这与链拔出过程中粘性溶剂阻力的增韧作用相反，增韧作用在几mm s（-1）以上变得有效。我们扩展了以前的模型[T]。Baumberger, Nat. Mater. 5,552(2006)]来解释这两种机制并估计微观解压缩速率。
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 thermoreversibility, thermally activated "unzipping" of the noncovalent cross-link zones results in slow crack propagation, prevailing 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 [T. Baumberger , Nat. Mater. 5, 552 (2006)] to account for both mechanisms and estimate the microscopic unzipping rates.