论文标题
三体胶体凝胶的不均匀稳定剪切动力学
Inhomogeneous steady shear dynamics of a three-body colloidal gel former
论文作者
论文摘要
我们使用自适应的布朗动力学模拟研究了在不均匀的外剪切力下胶体凝胶的固定流动。粒子室内力源自Stillinger-weber电位，其中三体项被调节以使网络形成和平衡中的凝胶化。当受到剪切力场的影响时，系统会在单体密度曲线中产生显着的调制。根据剪切幅度，颗粒在静止区域或最大净流的附近积累，我们推断出这种强烈的非平衡响应以成为凝胶状态的特征。研究内力的成分平行并垂直于流动方向，这表明固定状态的新出现和结构是由明显的粘性和结构性超绝热力驱动的。因此，观察到的非平衡现象的大小和性质与简单流体的相应行为不同。我们证明，一种简单的功能理论可以准确地重现粘性力谱，从而使系统的复杂动力学行为具有理由。
We investigate the stationary flow of a colloidal gel under an inhomogeneous external shear force using adaptive Brownian dynamics simulations. The interparticle forces are derived from the Stillinger-Weber potential, where the three-body term is tuned to enable network formation and gelation in equilibrium. When subjected to the shear force field, the system develops remarkable modulations in the one-body density profile. Depending on the shear magnitude, particles accumulate either in quiescent regions or in the vicinity of maximum net flow, and we deduce this strong non-equilibrium response to be characteristic of the gel state. Studying the components of the internal force parallel and perpendicular to the flow direction reveals that the emerging flow and structure of the stationary state are driven by significant viscous and structural superadiabatic forces. Thereby, the magnitude and nature of the observed non-equilibrium phenomena differs from the corresponding behavior of simple fluids. We demonstrate that a simple power functional theory reproduces accurately the viscous force profile, giving a rationale of the complex dynamical behavior of the system.
