The significance and magnitude of the line tension in three-phase (solid-liquid-fluid) systems

The excess energy of the three-phase system per unit length of the three-phase contact line is attributed to the line tension, a one-dimensional analog of the surface tension. The interpretation and magnitude of the line tension in three-phase systems that include a solid phase, and experimental techniques used for line tension determination are reviewed. The significance of the line tension in three-phase systems is discussed in relation to contact angle measurements for a liquid at a solid substrate of varying surface quality. Also discussed is the contribution of the linear free energy to the energy of attachment (detachment) of fine particles at (from) an interface.