binodal curve

A binodal curve is a boundary line on a phase diagram that shows the conditions (such as temperature and composition) where a substance can exist as two distinct liquid phases simultaneously. Inside this curve, the material separates into two different liquids with different properties; outside, it remains as a single uniform phase. The curve helps understand when materials will mix or separate, which is important in processes like alloy production or drug formulation. Essentially, it maps the limits of stability for single-phase and two-phase mixtures, guiding scientists in controlling material behaviors.