zetapotenciál

Zetapotenciál, also known as zeta potential, is a measure of the electrical potential at the slipping plane (or surface of zero mobility) that surrounds a charged particle suspended in a fluid. It is a key concept in colloid chemistry and surface science, providing insights into the stability of colloidal dispersions. The zetapotenciál is determined by the net charge on the surface of the particle and the ionic environment in the surrounding liquid.

When a charged particle is dispersed in a liquid, ions in the liquid tend to accumulate around it. This forms an electrical double layer consisting of a compact layer of counter-ions immediately adjacent to the particle surface and a diffuse layer of ions extending further into the bulk liquid. The slipping plane is an imaginary boundary within this double layer, beyond which the liquid is considered to move freely with the bulk. The zetapotenciál represents the electrical potential at this slipping plane relative to the bulk liquid.

A higher absolute value of zetapotenciál generally indicates greater electrostatic repulsion between particles, leading to a more stable dispersion with a reduced tendency for aggregation or sedimentation. Conversely, a zetapotenciál close to zero suggests that electrostatic forces are weak, and particles may be more prone to aggregation due to attractive forces like van der Waals forces. Factors such as pH, ionic strength, and the presence of specific ions can significantly influence the zetapotenciál of a system. It is commonly measured using electrophoresis, where the electrophoretic mobility of particles is determined and then related to the zetapotenciál through mathematical models.