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The zeta potential is an important and readily measurable indicator of the stability of colloidal dispersions. The magnitude of the zeta potential indicates the degree of electrostatic repulsion between adjacent, similarly charged particles in a dispersion. For molecules and particles that are small enough, a high zeta potential will confer ...
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 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.
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
where ε r is the dielectric constant of the dispersion medium, ε 0 is the permittivity of free space (C 2 N −1 m −2), η is dynamic viscosity of the dispersion medium (Pa s), and ζ is zeta potential (i.e., the electrokinetic potential of the slipping plane in the double layer, units mV or V).
Zeta potential is a calculated rather than measured property, and is a function of both the nanoparticle of interest and its surrounding medium, requiring a description of the measurement temperature; the composition, pH, viscosity, and dielectric constant of the medium; and value used for the Henry function to be meaningful.
In a colloidal suspension, particles will settle very slowly or not at all because the colloidal particles carry surface electrical charges that mutually repel each other. This surface charge is most commonly evaluated in terms of zeta potential, the electrical potential at the slipping plane. To induce coagulation, a coagulant (typically a ...
Usually zeta potential is used for estimating the degree of DL charge. A characteristic value of this electric potential in the DL is 25 mV with a maximum value around 100 mV (up to several volts on electrodes [22] [27]). The chemical composition of the sample at which the ζ-potential is 0 is called the point of zero charge or the iso-electric ...