Department of Chemical Engineering, Stanford University, Stanford, California 94305-5025, USA.
Langmuir. 2010 Mar 2;26(5):3160-4. doi: 10.1021/la903099a.
Experiments are described where two oil/water interfaces laden with charged particles move at close proximity relative to one another. The particles on one of the interfaces were observed to be attracted toward the point of closest approach, forming a denser particle monolayer, while the particles on the opposite interface were repelled away from this point, forming a particle depletion zone. Such particle attraction/repulsion was observed even if one of the interfaces was free of particles. This phenomenon can be explained by the electrostatic interaction between the two interfaces, which causes surface charges (charged particles and ions) to redistribute in order to satisfy surface electric equipotential at each interface. In a forced particle oscillation experiment, we demonstrated the control of charged particle positions on the interface by manipulating charge interaction between interfaces.
实验描述了两个带电荷粒子的油水界面彼此靠近移动。观察到一个界面上的粒子被吸引到最近的接触点，形成更密集的粒子单层，而相对界面上的粒子则被排斥远离该点，形成粒子耗尽区。即使一个界面上没有粒子，也观察到这种粒子吸引/排斥现象。这种现象可以通过两个界面之间的静电相互作用来解释，这导致表面电荷（带电粒子和离子）重新分布，以满足每个界面的表面等电位。在强制粒子振荡实验中，我们通过操纵界面之间的电荷相互作用来控制界面上带电粒子的位置。
