SUPA, School of Physics and Astronomy, The University of Edinburgh, King's Buildings, Peter Guthrie Tait Road, Edinburgh EH9 3FD, United Kingdom.
Phys Rev Lett. 2022 Jun 17;128(24):248002. doi: 10.1103/PhysRevLett.128.248002.
We show that mixing a colloidal gel with larger, non-Brownian grains generates novel flow-switched bistability. Using a combination of confocal microscopy and rheology, we find that prolonged moderate shear results in liquefaction by collapsing the gel into disjoint globules, whereas fast shear gives rise to a yield-stress gel with granular inclusions upon flow cessation. We map out the state diagram of this new "mechanorheological material" with varying granular content and demonstrate that its behavior is also found in separate mixture using different particles and solvents.
我们表明，将胶体凝胶与较大的、非布朗运动的颗粒混合会产生新颖的流切换双稳性。我们采用共聚焦显微镜和流变学的组合方法，发现长时间适度剪切会通过将凝胶坍塌成不连续的小球而导致液化，而快速剪切会在停止流动时产生具有颗粒夹杂的屈服应力凝胶。我们用不同的颗粒和溶剂在单独的混合物中也发现了这种“力学流变材料”的行为。
