2012/11/16 by Guillaume Ovarlez, Laurent Tocquer, Ovarlez, Guillaume +4 · 1 citation
Agricultural and Biological Sciences · Chemical Engineering · #FOS: Physical sciences #Polysaccharides Composition and Applications #Rheology and Fluid Dynamics Studies #Soft Condensed Matter (cond-mat.soft)
paper · doi:10.48550/arxiv.1211.3829
openalex publication_date 2012/11/16 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We show that besides simple or thixotropic yield stress fluids there exists a third class of yield stress fluids. This is illustrated through the rheological behavior of a carbon black suspension, which is shown to exhibit a viscosity bifurcation effect around a critical stress along with rheopectic trends, i.e., after a preshear at a given stress the fluid tends to accelerate when it is submitted to a lower stress. Viscosity bifurcation displays here original features: the yield stress and the critical shear rate depend on the previous flow history. The most spectacular property due to these specificities is that the material structure can be adjusted at will through an appropriate flow history. In particular it is possible to tune the material yield stress to arbitrary low values. A simple model assuming that the stress is the sum of one component due to structure deformation and one component due to hydrodynamic interactions predicts all rheological trends observed and appears to well represent quantitatively the data.