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In other words, zeta potential is the potential difference between the dispersion medium and the stationary layer of fluid attached to the dispersed particle. The zeta potential is caused by the net electrical charge contained within the region bounded by the slipping plane, and also depends on the location of that plane. Thus, it is widely ...
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]
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).
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]
Electric potential at this plane is called electrokinetic potential or zeta potential (also denoted as ζ-potential). [25] [26] The electric potential on the external boundary of the Stern layer versus the bulk electrolyte is referred to as Stern potential. Electric potential difference between the fluid bulk and the surface is called the ...
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.
The stability of particles, colloidal or otherwise, is most commonly evaluated in terms of zeta potential. This parameter provides a readily quantifiable measure of interparticle repulsion, which is the key inhibitor of particle aggregation. Similar agglomeration processes occur in other dispersed systems too.
Storing a dispersion at high temperatures enables simulation of real life conditions for a product (e.g. tube of sunscreen cream in a car in the summer), but also to accelerate destabilisation processes up to 200 times including vibration, centrifugation and agitation are sometimes used. They subject the product to different forces that pushes ...