Figure 1.

Coexisting surfaces at constant temperature for the ternary γS–PEG1450–water system. The pairs of points representing the coexisting phases (circles) are connected by the tie lines (solid lines). The dashed curve is a guide for the eye and the vertical bar locates the critical point at c = 260 mg/ml. The normalized slope of the tie lines at the critical point is (∂c_2s/∂c₁)/c = (−2.1 ± 0.1)10⁻³ mg⁻¹⋅ml.