2006/05/16 by Tristan Baumberger, Christiane Caroli, David Martina +6 · 8 citations
Biochemistry, Genetics and Molecular Biology · Engineering · Physics and Astronomy · #3D Printing in Biomedical Research #Advanced Materials and Mechanics #Hydrogels: synthesis, properties, applications #cond-mat.soft
paper · pdf · doi:10.1038/nmat1666
published as Nature Materials 5 (2006) 552
arxiv created 2006/05/16 · arxiv updated 2009/12/01 · openalex publication_date 2010/03/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/06/11
The resistance to fracture of reversible biopolymer hydrogels is an important control factor of the textural characteristics of food gels (such as gummy candies and aspic preparations). It is also critical for their use in tissue engineering, for which mechanical protection of encapsulated components is needed. Its dependence on loading rate and, recently, on the density and strength of crosslinks has been investigated. But, so far, no attention has been paid to solvent or to environment effects. Here we report a systematic study of crack dynamics in gels of gelatin in water/glycerol mixtures. We show in this model system that increasing solvent viscosity slows down cracks; moreover soaking with solvent markedly increases gel fragility; finally tuning the viscosity by adding a miscible liquid affects crack propagation through diffusive invasion of the crack tip vicinity. The results highlight the fact that fracture occurs by viscoplastic chain pull-out. This mechanism, as well as the related phenomenology, should be common to all reversibly crosslinked (physical) gels.