Electrostatic repulsion charged plates

Effect of the Size of the Small Particles on the Force. Three values for the particle diameter are considered in Figure 5, and the force was calculated for negative charges ofthe plates and the particles. The force is the same for all three sizes for distances between the plates smaller than the smallest particle diameter. However, when the distance between the plates becomes equal to the diameter of the smallest particle, the force acting on the plates first increases and then becomes positive. At this distance, the electrostatic interaction is dominant and the net force repulsive. For the other two sizes, the force increases as soon as the distance between the plates becomes equal to their diameters. These two sizes of particles can enter in the gap between the plates for relatively large distances between the plates at which the electrostatic repulsion is relatively weak. For this reason, the net forces for particles of these two sizes are smaller than that for the particle of the smallest size. 

FIGURE 103 Electrostatic repulsion force, F/njAg T versus separation, h, between two identically charged plates with surface potentials of 25 mV in a 1 1 electrolyte solution at 0.001 Hf according to the exact theory with either constant charge or constant potential boundary conditions. Calculated from F = n Jk T (A - A ) with definitions of Aj given in the text for constant charge and potential boundary conditions. 

Consider now two parallel flat surfaces, each with equal charge density a, separated by a distance D. Although charged, there is no net electrostatic repulsion of the surfaces, since the counterions in the gap between the plates cancel the charges on the plates. However, because the counterions must be drawn into the gap, there is an entropy cost that becomes greater as... 

We can visualize that when our hair is rubbed with a plastic plate, strands of hair stand up from the scalp due to electrostatic repulsion among them. Similarly, when charged functional groups, such as diethylamino groups, are introduced onto the graft chains, the polymer chains extend from the pore surface due to their mutual repulsion. This extended polymer brush conformation provides the protein with three-dimensional binding sites. The multilayer binding of various proteins onto the ion-... 

An expression for the force of electrostatic repulsion between two charged crossed hemicylindrical surfaces is given in Equation (3.5) and in fact this turns out to be equivalent to interaction between a sphere and a flat plate. Integration of this expression leads directly to the potential energy of electrostatic repulsion, namely. 

Figures 1 and 2 summarize the results computed for the double-layer interaction between two parallel plates. Each figure presents the charge density and electrostatic potential of both interacting surfaces, together with the double-layer force per unit area (p > 0 denotes repulsion), as a function of the dimensionless separation...

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