Transport coefficients and mechanical response in hard-disk colloidal suspensions*
Transport coefficients and mechanical response in hard-disk colloidal suspensions*
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DOI:
10.1088/1674-1056/25/11/116101
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发表时间:
2016-09
影响因子:
1.7
通讯作者:
Bokai Zhang;Jian Li;Kang Chen;Wen-de Tian;Yu-qiang Ma
中科院分区:
文献类型:
--
作者:
Bokai Zhang;Jian Li;Kang Chen;Wen-de Tian;Yu-qiang Ma
We investigate the transport properties and mechanical response of glassy hard disks using nonlinear Langevin equation theory. We derive expressions for the elastic shear modulus and viscosity in two dimensions on the basis of thermal-activated barrier-hopping dynamics and mechanically accelerated motion. Dense hard disks exhibit phenomena such as softening elasticity, shear-thinning of viscosity, and yielding upon deformation, which are qualitatively similar to dense hard-sphere colloidal suspensions in three dimensions. These phenomena can be ascribed to stress-induced “landscape tilting”. Quantitative comparisons of these phenomena between hard disks and hard spheres are presented. Interestingly, we find that the density dependence of yield stress in hard disks is much more significant than in hard spheres. Our work provides a foundation for further generalizing the nonlinear Langevin equation theory to address slow dynamics and rheological behavior in binary or polydisperse mixtures of hard or soft disks.