تقرير
Residual stresses and shear-induced overaging in boehmite gels
| العنوان: | Residual stresses and shear-induced overaging in boehmite gels |
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| المؤلفون: | Sudreau, Iana, Auxois, Mathilde, Servel, Marion, Lécolier, Éric, Manneville, Sébastien, Divoux, Thibaut |
| المصدر: | Physical Review Materials 6, L042601 (2022) |
| سنة النشر: | 2022 |
| المجموعة: | Condensed Matter Physics (Other) |
| مصطلحات موضوعية: | Condensed Matter - Soft Condensed Matter, Condensed Matter - Materials Science, Physics - Applied Physics |
| الوصف: | Colloidal gels respond like soft solids at rest, whereas they flow like liquids under external shear. Starting from a fluidized state under an applied shear rate $\dot\gamma_{p}$, abrupt flow cessation triggers a liquid-to-solid transition during which the stress relaxes towards a so-called \textit{residual stress} $\sigma_{\rm res}$ that tallies a macroscopic signature of previous shear history. Here, we report on the liquid-to-solid transition in gels of boehmite, an aluminum oxide, that shows a remarkable non-monotonic stress relaxation towards a residual stress $\sigma_{\rm res}(\dot\gamma_{p})$ characterized by a dual behavior relative to a critical value $\dot\gamma_{c}$ of the shear rate $\dot\gamma_{p}$. Following shear at $\dot\gamma_{p}>\dot\gamma_{c}$, the gel obtained upon flow cessation is insensitive to shear history, and the residual stress is negligible. However, for $\dot\gamma_{p}<\dot\gamma_{c}$, the gel encodes some memory of the shear history, and $\sigma_{\rm res}$ increases for decreasing shear rate, directly contributing to reinforcing the gel viscoelastic properties. Moreover, we show that both $\sigma_{\rm res}$ and the gel viscoelastic properties increase logarithmically with the strain accumulated during the shear period preceding flow cessation. Such a shear-induced "overaging" phenomenon bears great potential for tuning the rheological properties of colloidal gels. Comment: 5 pages, 4 figures |
| نوع الوثيقة: | Working Paper |
| DOI: | 10.1103/PhysRevMaterials.6.L042601 |
| URL الوصول: | http://arxiv.org/abs/2201.02528 |
| رقم الأكسشن: | edsarx.2201.02528 |
| قاعدة البيانات: | arXiv |
| DOI: | 10.1103/PhysRevMaterials.6.L042601 |
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