Cates M E, Fielding S M, Marenduzzo D, Orlandini E, Yeomans J M
SUPA, School of Physics, University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom.
Phys Rev Lett. 2008 Aug 8;101(6):068102. doi: 10.1103/PhysRevLett.101.068102.
We study numerically the rheological properties of a slab of active gel close to the isotropic-nematic transition. The flow behavior shows a strong dependence on the sample size, boundary conditions, and on the bulk constitutive curve, which, on entering the nematic phase, acquires an activity-induced discontinuity at the origin. The precursor of this within the metastable isotropic phase for contractile systems (e.g., actomyosin gels) gives a viscosity divergence; its counterpart for extensile suspensions admits instead a shear-banded flow with zero apparent viscosity.
我们对接近各向同性-向列相转变的活性凝胶板的流变特性进行了数值研究。流动行为显示出对样品尺寸、边界条件以及本体本构曲线有强烈依赖性，当进入向列相时，本体本构曲线在原点处会出现由活性诱导的不连续性。对于收缩系统（如肌动球蛋白凝胶），在亚稳各向同性相内这种不连续性的先兆会导致粘度发散；而对于拉伸悬浮液，其对应情况则允许出现表观粘度为零的剪切带流。
