Statistical Physics Study of Supercooled Colloidal Liquids and Colloidal Glass Transition

我们对胶体玻璃化转变进行了理论研究和大量的计算机模拟，得到了以下重要结果：1）为了阐明胶体之间的流体力学相互作用在玻璃化转变附近的重要作用，我们对硬球体系进行了两种类型的计算机模拟，布朗动力学模拟和分子动力学模拟。通过基于Tokuyama最近提出的平均场理论从统一的观点分析数据，因此，我们首先表明，没有流体动力学相互作用，玻璃化转变就不会发生。2）我们数值求解了Tokuyama在2001年从第一原理导出的密度波动的非线性随机扩散方程，然后表明，长-由玻璃化转变附近的非线性密度涨落引起的空间不均匀性是著名的两步弛豫的重要起源。3）Tokuyama通过从非线性随机扩散方程导出均方位移的非线性方程，提出了平均场理论。它已被证明不仅适用于胶体悬浮液，但也为玻璃形成材料，通过分析几个不同的实验和模拟数据。因此，该理论预测了不同的玻璃化转变之间的显着相似性，并提出了一种与传统方法完全不同的方法来理解玻璃化转变，包括对数衰减和任何特征时间没有分歧。

We have studied the colloidal glass transitions not only by constructing the theory but also by performing the extensive computer simulations and obtained the following important achievements.1)In order to clarify how the hydrodynamic interactions between colloids play an important role near the glass transition, we have performed two types of computer simulations on the systems of hard spheres, the Brownian-dynamics simulation and the molecular-dynamics simulation. By analyzing the data from a unified point of view based on the mean-field theory proposed recently by Tokuyama, we have thus first shown that the glass transition can not occur without the hydrodynamic interactions.2)We have numerically solved the nonlinear stochastic diffusion equation for the density fluctuations derived in 2001 by Tokuyama from a first principle and then shown that the long-lived spatial heterogeneities caused by the nonlinear density fluctuations near the glass transition are an important origin of a famous two-step relaxation.3)Tokuyama has proposed the mean-field theory by deriving the nonlinear equation for the mean-square displacement from the nonlinear stochastic diffusion equation. It has been shown to be applicable not only for colloidal suspensions but also for glass-forming materials by analyzing several different experimental and simulation data. The theory thus predicts remarkable similarities between different glass transitions and proposes an approach quite different from the conventional ones to understand the glass transition, including a logarithmic decay and no divergence of any characteristic times.