The basis of DLVO is to use the sum of the repulsive force (V R – electrostatic BORN forces) and attractive (VA – van der WAALS forces) to calculate the particle interaction potential. Using DLVO theory, it is possible to assess the stability of suspensions and emulsions by means of the zeta potential.
The zeta potential is a consequence of the existence of surface charge, and can give information on electrical interaction forces between the dispersed particles. The zeta potential ( x ), or electrophoretic mobility (µ E), is increasingly being used to investigate fine particle systems. This potential is usually more of interest because particles interact according to the magnitude of this value, rather than the potential at the surface of the particle. Instead the charge at a distance from the particle, called the zeta potential is measured. The surface charge cannot be measured directly. This is an important factor in determining the interactions between particles, and hence dispersion characteristics such as dispersion stability, flocculation, viscosity, film forming characteristics etc. One of the significant surface properties is the surface charge. Particle size is often considered one of the most important parameters, however, as particle size reduces, the surface area increases significantly in comparison with the volume, so surface properties increasingly determine the dispersions characteristics. There are many aspects of a particle dispersion that need to be investigated to fully characterize a system. Methods for determining the zeta potentialĪpplications – possibilities for automation
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