How much does the core structure of a three-phase contact line contribute to the line tension near a wetting transition?

摘要: We initially simplify a three-phase contact line to 'primitive' star-shaped structure formed by three planar interfaces meeting at common of intersection, and calculate the tension associated with this primitive picture. Next, we consider well-known more refined picture that includes 'core structure' consisting interface deviations away from The corresponding properties were calculated earlier, within mean-field theory, using an displacement model or microscopic density-functional theory. question ask is what extent thermodynamic near wetting phase transition can be attributed core structure. To answer it compare our result for contribution known full (within theory). While calculation provides surprisingly useful upper bound critical transition, nontrivial first-order found responsible important difference between provided calculation. This accounts also discrepancy tensions two different methods in earlier transition.