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Zeta potential titration is a titration of heterogeneous systems, for example colloids and emulsions. Solids in such systems have very high surface area. This type of titration is used to study the zeta potential of these surfaces under different conditions. Details of zeta potential definition and measuring techniques can be found in the ...
Zeta potential can also be calculated using theoretical models, and an experimentally-determined electrophoretic mobility or dynamic electrophoretic mobility. Electrokinetic phenomena and electroacoustic phenomena are the usual sources of data for calculation of zeta potential. (See Zeta potential titration.)
The potential of zero charge is used for determination of the absolute electrode potential in a given electrolyte. IUPAC also defines the potential difference with respect to the potential of zero charge as: E pzc = E − E σ=0. where: E pzc is the electrode potential difference with respect to the point of zero charge, E σ=0
Zeta potential titrations are titrations in which the completion is monitored by the zeta potential, rather than by an indicator, in order to characterize heterogeneous systems, such as colloids. [38] One of the uses is to determine the iso-electric point when surface charge becomes zero, achieved by changing the pH or adding surfactant.
Electrokinetic phenomena generally measure zeta potential, and a zero zeta potential is interpreted as the point of zero net charge at the shear plane. This is termed the isoelectric point. [29] Thus, the isoelectric point is the value of pH at which the colloidal particle remains stationary in an electrical field.
DLVO theory is a theory of colloidal dispersion stability in which zeta potential is used to explain that as two particles approach one another their ionic atmospheres begin to overlap and a repulsion force is developed. [1]
Smoluchowski's sedimentation potential is defined where ε 0 is the permitivity of free space, D the dimensionless dielectric constant, ξ the zeta potential, g the acceleration due to gravity, Φ the particle volume fraction, ρ the particle density, ρ o the medium density, λ the specific volume conductivity, and η the viscosity. [8]
where U is the velocity vector, ρ is the density of the fluid, / is the material derivative, μ is the viscosity of the fluid, ρ e is the electric charge density, ϕ is the applied electric field, ψ is the electric field due to the zeta potential at the walls and p is the fluid pressure.