Yielding of binary colloidal glasses
Yielding of binary colloidal glasses
复制标题
二元胶体玻璃的产率
DOI：
--
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
S. Egelhaaf
中科院分区：
文献类型：
--
作者：
T. Sentjabrskaja;E. Babaliari;J. Hendricks;M. Laurati;G. Petekidis;S. Egelhaaf
实验研究了胶体玻璃对振荡剪切的流变响应，特别是非线性响应。玻璃是高度浓缩的二元硬球混合物，具有相对较大的尺寸差异。对于0.2的尺寸比，在加入第二种物质后，观察到归一化弹性模量、屈服应变和应力的强烈降低，并且对于一些样品，甚至观察到玻璃熔融成流体。这归因于更有效的填充，如随机紧密填充向更大的总体积分数的转变所示。这导致自由体积增加，这有利于融合器变形，从而导致融合器松动。笼变形也有利于第二个物种引入的结构异质性。对于一个有限的参数范围内，我们还发现了两步屈服的迹象，如以前报道的有吸引力的眼镜。在样品中含有更可比的大小，即0.38的大小比的领域，笼似乎较少扭曲和结构的不均匀性，在更大的长度尺度似乎变得重要。有限的结构变化仅反映在模量、屈服应变和应力的小幅降低上。
The rheological response, in particular the non-linear response, to oscillatory shear is experimentally investigated in colloidal glasses. The glasses are highly concentrated binary hard-sphere mixtures with relatively large size disparities. For a size ratio of 0.2, a strong reduction of the normalized elastic moduli, the yield strain and stress and, for some samples, even melting of the glass to a fluid is observed upon addition of the second species. This is attributed to the more efficient packing, as indicated by the shift of random close packing to larger total volume fractions. This leads to an increase in free volume which favours cage deformations and hence a loosening of the cage. Cage deformations are also favoured by the structural heterogeneity introduced by the second species. For a limited parameter range, we furthermore found indications of two-step yielding, as has been reported previously for attractive glasses. In samples containing spheres with more comparable sizes, namely a size ratio of 0.38, the cage seems less distorted and structural heterogeneities on larger length scales seem to become important. The limited structural changes are reflected in only a small reduction of the moduli, yield strain and stress.
DOI：
10.1103/physreve.84.061136
发表时间：
2011-08
期刊：
Physical review. E, Statistical, nonlinear, and soft matter physics
影响因子：
--
作者：
Douglas J. Ashton;N. Wilding;R. Roth;R. Evans
通讯作者：
Douglas J. Ashton;N. Wilding;R. Roth;R. Evans
影响因子：
8.6
作者：
Koumakis, N.;Laurati, M.;Petekidis, G.
通讯作者：
Petekidis, G.