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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 ...
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
The iso-electric point is one such property. The iso-electric point is the pH value at which the zeta potential is approximately zero. At a pH near the iso-electric point (± 2 pH units), colloids are usually unstable; the particles tend to coagulate or flocculate. Such titrations use acids or bases as titration reagents.
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.
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 ...
RBCs have a net negative charge called zeta potential which causes them to have a natural repulsion for one another. Potentiators reduce the zeta potential of RBC membranes. Common potentiators include low ionic strength solution (LISS), albumin , polyethylene glycol (PEG), and proteolytic enzymes .
The relation between surface charge and surface potential can be expressed by the Grahame equation, derived from the Gouy-Chapman theory by assuming the electroneutrality condition, which states that the total charge of the double layer must be equal to the negative of the surface charge. Using the one-dimensional Poisson equation and assuming ...
In 1923, Peter Debye and Erich Hückel reported the first successful theory for the distribution of charges in ionic solutions. [7] The framework of linearized Debye–Hückel theory subsequently was applied to colloidal dispersions by S. Levine and G. P. Dube [8] [9] who found that charged colloidal particles should experience a strong medium-range repulsion and a weaker long-range attraction.