论文标题
在流体界面处附近金属或金属涂层胶体的静电对互动
Electrostatic pair-interaction of nearby metal or metal-coated colloids at fluid interfaces
论文作者
论文摘要
在本文中，我们从理论上研究了一对相同的胶体之间的静电相互作用，其恒定的表面电势在流体界面彼此紧密相邻。通过采用简化但合理的模型系统，该问题在经典密度功能理论的框架内解决，并线性化以及非线性泊松波尔茨曼（PB）理论。除了提供一个合理的理论框架外，通常适用于任何此类问题，我们的新发现（所有这些都与共同信念相矛盾）还包括以下内容：首先，定量，定量以及在线性和非线性PB理论中获得的相互作用之间的差异；其次，界面系统中无处不在的三相接触线之间的静电相互作用的重要性；第三，一对相同的金属胶体之间存在吸引人的静电相互作用。我们报道的不寻常的吸引力在很大程度上源于有吸引力的线相互作用，尽管该线路相互作用与粒子的大小线性缩放，但可以与表面相互作用竞争，并且可以足够强大以改变总静电相互作用的性质。我们的结果应在金属或金属涂层的颗粒型乳液中找到应用，在这些乳液中，不仅经常观察到密集的颗粒阵列，而且有时需要。
In this paper, we theoretically study the electrostatic interaction between a pair of identical colloids with constant surface potentials sitting in close vicinity of each other at a fluid interface. By employing a simplified yet reasonable model system, the problem is solved within the framework of classical density functional theory and linearized as well as nonlinear Poisson-Boltzmann (PB) theory. Apart from providing a sound theoretical framework generally applicable to any such problem, our novel findings, all of which contradict common beliefs, include the following: first, quantitative as well as qualitative differences between the interactions obtained within the linear and the nonlinear PB theories; second, the importance of the electrostatic interaction between the omnipresent three-phase contact lines in interfacial systems; and third, the occurrence of an attractive electrostatic interaction between a pair of identical metal colloids. The unusual attraction we report on largely stems from an attractive line interaction which although scales linearly with the size of the particle, can compete with the surface interactions and can be strong enough to alter the nature of the total electrostatic interaction. Our results should find applications in metal or metal-coated particle-stabilized emulsions where densely packed particle arrays are not only frequently observed but are sometimes required.
