Electrical Double Layer Potential

Fig. 7. The van der Waals potential between droplets is increasingly negative with reduced interdroplet distance, whereas the electric double-layer potential...

The relative value of the two potentials reveals the destabdization action of salts added to the emulsion. Addition of an electrolyte to the continuous phase causes a reduction of the electric double-layer repulsion potential, whereas the van der Waals potential remains essentially unchanged. Hence, the reduced electric double-layer potential causes a corresponding reduction of the maximum in the total potential, and at a certain concentration of electrolyte the maximum barrier height is reduced to a level at which the stabdity is lost. 

Clavilier eta/.196,794-796have studied CO adsorption on electrochemi-cally faceted Pt(lll) and Pt(110) electrodes and from the charge transients, with the provision that the CO dipole has a negligible contribution to the electrical double-layer potential these authors have provided a definite determination of ( =o- However, electrochemically faceted Pt(lll) electrodes have a polycrystalline surface structure, and thus the value of Eq-q for such electrodes lies between fiULO for terraces and forst s.197 786 787... 

The potential of each channel may be composed of two potentials. One is an oxidation-reduction potential generating at the boundary surface between the Ag electrode and the lipid membrane. The other is a Donnan potential at the boundary between the lipid membrane and the aqueous medium or more generally a Gouy-Chapman electrical double-layer potential formed in the aqueous medium [24]. Figure 7 shows a potential profile near the lipid membrane. The oxidation-reduction potential would not be affected by the outer solution in short time, because the lipid membrane had low permeability for water. Then the measured potential change by application of the taste solution is mainly due to the change in the surface electrical potential. 

Solving the Poisson-Boltzmann equation with proper boundary conditions will determine the local electrical double layer potential field y/ and hence, via Eq.(3), the local net charge density distribution. 

Figure 2 Non-dimensional electric double layer potential profile in a quarter section of a rectangular microchannel with ic >h = 79, = 8 and If = 2 3.

Electric Double-Layer Potential and Net Charge Density... 

Biological macromolecules are often handled through microfluidic systems, in which these molecules can transport and react. A common driving force behind such microfluidic transport processes is the electrokinetic force, which originates as a consequence of interaction between the electric double-layer potential distribution and the applied electric field. This entry discusses some of the important features of the biochemical reactions in such microfiuidic systems. 

Electrical Double Layer Potential in the Conducting Liquids... 

X 10 exp(1713/r). p and p are the solution density and hydrodynamic pressure, respectively. From Eq. (3a), it can be seen that the evaluation of the momentum equation requires a description of the net charge density, pe. and the total electrical potential, It is assumed that <1) can be decoupled as the summation of the electrical double layer potential, ijr, and the applied electric potential, , as expressed in Eq. (4)... 

Ruckenstein (Ruckenstein and Chi, 1975 Friberg and Venable, 1983 Flanagan and Singh, 2006) explored the stability and size of microemulsion domains based on a thermodynamic approach where interactions (Van der Waals forces, electric double layer potential, and free energy and entropy of formation) were considered. He studied the dependence of the free... 

Potential shape in TIRM. The total potential is given by the electric double-layer potential described by the DLVO theory and the gravitational potential. With the particle radius R, the particle and liquid densities gp and Qj, and the Debye length Xd,... 

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