Imbibition

Imbibition is defined as the displacement of one fluid by another immiscible fluid. This process is controlled and affected by a variety of factors. In spontaneous imbibition of wetting liquids into porous media (also called wicking), the capillary pressure, created as a result of interplay of the liquid and solid surface energies, is responsible for the spontaneous suction of the liquids. The capillary number (Ca) and the mobility ratio (M) have the greatest importance. It is also defined as the phenomenon by which the living or dead plant cell absorbs water by surface attraction. A classification of imbibition processes was given by Payatakes and Dias: