Lecture 21: Particle Interaction Energies, Hamaker Constant, EDL, and the Gouy-Chapman Model

In this second lecture of Chapter 8, we will begin by discussing the most common interactions found in a hydrophobic colloid: the universal van der Waals attractive forces and electrostatic forces, which can be either attractive or repulsive. To describe the electrostatic interaction, we must describe the influence a charged surface has on the surrounding solution, which results in a broad layer of counter-ions. This so-called diffuse layer neutralizes the surface charge. The combination of the charged surface and diffuse layer composes the Electric Double Layer, which will be described initially with the Gouy-Chapman model.