Non-miscible

Non-miscible describes two or more liquids that are incapable of mixing to form a homogeneous solution. This typically occurs due to differences in molecular polarity, intermolecular forces (like hydrogen bonding), or the absence of favorable interactions that would promote mixing. Instead of dissolving into one another, non-miscible liquids will typically separate into distinct layers, often with the denser liquid settling to the bottom. This separation is driven by the tendency of the liquid molecules to associate with others of similar chemical structure rather than forming uniform distribution across one another. They remain physically distinct and exhibit a clear interface between the phases, the degree of miscibility often dependent upon their specific composition and under what temperature and pressure the liquids are at.

Non-miscible meaning with examples

• Oil and water are famously non-miscible; when combined, they separate into distinct layers, with the less dense oil floating on top of the denser water. This phenomenon is exploited in various applications like oil spills cleanups using dispersants.
• In salad dressings, oil and vinegar (a water-based liquid) remain non-miscible unless emulsifiers are added. The absence of these emulsifiers means the dressing requires shaking before each use to ensure a uniform flavor and texture.
• The process of extracting compounds from a solution often relies on the use of non-miscible solvents. A desired substance can be selectively drawn into a suitable, immiscible solvent to separate it from the other components in the original mixture.
• During the distillation of certain essential oils, the oil often separates from the water by being non-miscible. This allows for easy collection after the distillation process, creating a pure product.
• Certain paints are made up of non-miscible pigment and binding agents. These ingredients when combined are intended to remain separate enough to create an opaque or textured appearance on application.