Slow dynamics of supercooled colloidal fluids: Spatial heterogeneities and nonequilibrium density fluctuations
Slow dynamics of supercooled colloidal fluids: Spatial heterogeneities and nonequilibrium density fluctuations
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过冷胶体流体的慢动力学：空间异质性和非平衡密度波动
DOI：
10.1063/1.1301471
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发表时间：
1999
期刊：
影响因子：
--
通讯作者：
M. Tokuyama
中科院分区：
文献类型：
--
作者：
M. Tokuyama
本文对中性和带电硬球两种模型悬浮液讨论了作者最近提出的自扩散系数动态异常的思想在研究平衡态和非平衡态过冷胶体液体中的作用。在接近胶体玻璃转变时，在平衡和非平衡系统中，长寿命、空间非均匀的玻璃域在中间时间形成。这些空间非均质性是造成密度波动缓慢松弛的原因。事实上，众所周知的类似于玻璃形成材料的现象，如α过程的拉伸和von Schweidler定律，都可以用这些空间结构的存在来解释。然而，在平衡系统中，这些非均质性很难被观察到，因为它们的大小和幅度与非平衡系统中的相比都很小。
How the idea of the dynamic anomaly of the self-diffusion coefficient recently proposed by the present author works on the study of equilibrium and nonequilibrium supercooled colloidal liquids is discussed for two kinds of model suspensions, neutral and charged hard-sphere suspensions. Near colloidal glass transition, the long-lived, spatially heterogeneous glassy domains are shown to be formed for intermediate times in equilibrium and nonequilibrium systems. Those spatial heterogeneities are responsible for the slow relaxation of the density fluctuations. In fact, the long-known phenomena similar to those in glass-forming materials, such as the stretching of the α process and the von Schweidler law, can be explained by the existence of those spatial structure. In the equilibrium system, however, those heterogeneities must be difficult to be observed since their sizes and magnitude are quite small compared to those in the nonequilibrium system.