Two-step yielding and directional strain-induced strengthening in dilute colloidal gels.
We investigate the nonlinear rheology of dilute, depletion-induced colloidal gels and report that these systems yield via a two-step process. We propose the two yield points to be associated with interparticle bond rotation and bond breakage, respectively. These distinct yielding mechanisms lead to remarkable creep profiles at intermediate values of the applied stress, highlighted by an anisotropic shear-induced strengthening and flow arrest at very large accumulated strains (γ∼ 80). The possible microstructural origins of this behavior are discussed.
Department of Chemical Engineering & Materials Science, University of California, Irvine, California, USA.
Hubert K
HK
Chan
Ali
A
Mohraz
D003102:Colloids / Q000737:chemistry*; D003198:Computer Simulation; D055119:Elastic Modulus; D005782:Gels / Q000737:chemistry*; D008956:Models, Chemical; D008958:Models, Molecular; D013314:Stress, Mechanical
D003102:Colloids; D005782:Gels