Adsorption

An increase of the concentration of a solute in the vicinity of a solid surface, over that in the bulk of the solution, due to the attractive interaction between the solid immersed into the solution and the solute. This term should not be confused with absorption, the key difference between absorption and adsorption is that absorption involves a substance being taken into the bulk of another material, while adsorption involves a substance adhering only to the surface of another material.