Surface Charge

Surface charge is the electric charge present at an interface. There are many different processes which can lead to a surface being charged, including adsorption of ions, protonation/deprotonation, and the application of an external electric field. Surface charge causes a particle to emit an electric field, which causes particle repulsions and attractions, and is responsible for many colloidal properties.

Surface charge practically always appears on an object surface when it is placed into a fluid. All fluids contain ions, positive (cations) and negative (anions). These ions interact with the object surface. This interaction might lead to the adsorption of some of them on the surface. If the number of adsorbed cations exceeds the number of adsorbed anions, the surface would gain total positive electric charge.

There is another possible mechanism leading to surface charging. It is dissociation of the surface chemical group.

Read more about Surface Charge:  Surface Charge Density, Interfacial Potential, Applications of Surface Charge

Famous quotes containing the words surface and/or charge:

    There’s something tragic in the fate of almost every person—it’s just that the tragic is often concealed from a person by the banal surface of life.... A woman will complain of indigestion and not even know that what she means is that her whole life has been shattered.
    Ivan Sergeevich Turgenev (1818–1883)

    What art thou that usurp’st this time of night,
    Together with that fair and warlike form
    In which the majesty of buried Denmark
    Did sometimes march? By heaven I charge thee speak!
    William Shakespeare (1564–1616)