Interplate distances

FIGURE 6.3 Distributions of small ions (n+ solid line n dashed line) for the interplate distance dx = 20 nm, the electrolyte concentration c = 0.001 mol T1 and the surface potential < >s = -4.0 in the Dirichlet model (the surface charge density Z0 = -0.084 nm-2 in the Neumann model). The origin of the coordinate x is taken at the midpoint between the container surfaces. 

FIGURE 6.10 Trajectories of the stable interplate distance d n plotted against the concentration c of the external soaking solution for three values of the surface potential s in the Dirichlet model. The width of the container is set to be 200 nm and D1 = Dr The swelling is enhanced for small values of <6S. ... 

In Figure 6.20, the trajectories of the interplate distance dmm (the smaller one) for the potential minimum are drawn for different values of s, showing the increase of the plate separation against the dilution of the salt concentration c. The interplate distance dm]n approaches DU as c —> 0. We note that the swelling is enhanced for... 

Figures 17b and 17c show the response in the lateral and normal directions to a lateral constant velocity drive for the stick slip regime that occurs at low driving velocities. This behavior is similar for the presently discussed model. The separation between the plates, which is initially Zq at equilibrium, starts growing before slippage occurs and stabilizes at a larger interplate distance as long as the motion continues. Since the static friction is determined by the amplitude of the potential corrugation exp(l — Z/A), it is obvious that the dilatancy leads to a decrease of the static friction compared to the case of a constant distance between plates.

Detailed ealeulations also exist for adsorbing polymers. They also show that for different types of eonhgnrations the chain segments extend from a single plate to distances that scale as (Hesselink, 1971 Hesselink et al., 1971). Evans and Napper (1977) and Vincent et al. (1980, 1986) provide expressions for an elastic contribntion to E. When the surfaces approach one another, the polymer chain segments see elastic deformations at very small interplate distances. For a sphere... 

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