Polyelectrolyte adsorption

Adsorption of polyelectrolytes on solid substrates is a surface phenomenon where long-chained polymer molecules with charged groups (dubbed polyelectrolytes) bind to a surface that is charged in the opposite polarity. On the molecular level, the polymers do not actually bond to the surface, but tend to "stick" to the surface via intermolecular forces and the charges created by the dissociation of various side groups of the polymer.

Source: Wikipedia — Polyelectrolyte adsorption (CC BY-SA 4.0)