Kinetic arrest and glass-glass transition in short-ranged attractive colloids.
Kinetic arrest and glass-glass transition in short-ranged attractive colloids.
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DOI：
10.1103/physreve.74.051504
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发表时间：
2006-10
期刊：
影响因子：
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通讯作者：
M. Sztucki;T. Narayanan;G. Belina;A. Moussaïd;Frédéric Pignon;H. Hoekstra
中科院分区：
文献类型：
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作者：
M. Sztucki;T. Narayanan;G. Belina;A. Moussaïd;Frédéric Pignon;H. Hoekstra
在模型胶体系统中，在较宽的体积分数范围内研究了热可逆排斥硬球到粘球的转变。通过高分辨率小角度 X 射线散射获得静态微观结构，通过动态 X 射线和光散射探测胶体动力学，并通过体流变学获得补充机械性能。在低浓度时，系统表现出气液型相分离的特征。本体相分离可能被中间体积分数范围内的凝胶化转变所中断。在高体积分数下，观察到流体吸引玻璃和排斥玻璃-吸引玻璃转变。结果表明，可以从绝对散射强度可靠地推导出颗粒的体积分数。使用 Percus-Yevick 近似的主阶级数展开，根据有吸引力的方阱势对静态结构因子进行建模。系综平均中间散射函数显示了吸引和排斥玻璃态中不同水平的冻结成分。观察到的静态和动态行为与模式耦合理论和方阱吸引系统数值模拟的预测一致。
A thermally reversible repulsive hard-sphere to sticky-sphere transition was studied in a model colloidal system over a wide volume fraction range. The static microstructure was obtained from high resolution small angle x-ray scattering, the colloid dynamics was probed by dynamic x-ray and light scattering, and supplementary mechanical properties were derived from bulk rheology. At low concentration, the system shows features of gas-liquid type phase separation. The bulk phase separation is presumably interrupted by a gelation transition at the intermediate volume fraction range. At high volume fractions, fluid-attractive glass and repulsive glass-attractive glass transitions are observed. It is shown that the volume fraction of the particles can be reliably deduced from the absolute scattered intensity. The static structure factor is modeled in terms of an attractive square-well potential, using the leading order series expansion of Percus-Yevick approximation. The ensemble-averaged intermediate scattering function shows different levels of frozen components in the attractive and repulsive glassy states. The observed static and dynamic behavior are consistent with the predictions of a mode-coupling theory and numerical simulations for a square-well attractive system.