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Advanced Oxidation Processes (AOP)

Zeta Potential Definition

Zeta potential also referred to as electrokinetic potential refers to a potential difference in a liquid characterizing electrochemical equilibrium on interfaces. This potential difference is the result of a residual, unbalanced charge distribution in the adjoining liquid, which produces a double layer. This potential depends on the properties of a liquid and the properties of the surface. It has a significant role in the theory of aggregative stability.

Electrokinetic potential is a prime indicator in the stability of colloidal dispersions. From the magnitude of this potential, the degree of electrostatic repulsion between similarly charged adjacent particles in the dispersion can be determined.

Electronkinetic Potential (n.d.).


Colloid Science Definition

A colloid is one of the three primary types of mixtures, with the other two being a solution and suspension. A colloid is a mixture that has particles ranging between 1 and 1000 nanometers in diameter, yet is still able to remain evenly distributed throughout the solution. These are also known as colloidal dispersions because the substances remain dispersed and do not settle to the bottom of the container. In colloids, one substance is evenly dispersed in another. The substance being dispersed is referred to as being in the dispersed phase, while the substance in which it is dispersed is in the continuous phase.

To be classified as a colloid, the substance in the dispersed phase must be larger than the size of a molecule but smaller than what can be seen with the naked eye. This can be more precisely quantified as one or more of the substance's dimensions must be between 1 and 1000 nanometers. If the dimensions are smaller than this the substance is considered a solution and if they are larger then the substance is a suspension.

Law, J. & Bar, A. (2020). Colloids 

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