Scaling of interfacial properties in ternary polymer blends

We analyze interfaces between A-righ and B-rich phases in symmetric ternary polymer blends with a non-selective C minority component. The interfacial tension σ and the interfacial thicknesses of the composition profiles of φ_A(cursive Greek chi) - φ_B(cursive Greek chi), and φ_C(cursive Greek chi), L₁ and L₂, respectively, are calculated by solving the linearized equation resulting from minimizing σ as a function of the average composition of C, φ̄_C = 1 - φ̄, with φ̄/2 = φ̄_A = φ̄_B&, and the net, interaction per thermal energy between components A and B, χ_AB = χ (χ_AC = χ_BC = ηχ). As φ̄_C increases the interfacial thickness increases and the interfacial tension decreases. Our results are in excellent agreement with the steady-state solution of the non-linear spinodal decomposition equations.