An emulsion results when multiple un-blendable liquids are combined. One of the liquids typically serves as a base through which particles of the other liquids spread or disperse. Two primary types exist: water-in-oil and oil-in-water emulsions. Both types are used in a number of creation processes, particularly in the medical field.
Emulsions are often recognizable by their cloudy or white appearance since the substances do not mix together in a unified manner. After a period of time, the mixed substance will often separate in one of three manners. The substance may divide into two or more easily identifiable layers consisting of the individual liquids in a process known as creaming. One or more of the substances may also become visible by forming flakes, called flocculation, or large blobs, called coalescence, in the main substance. Water and oil constitute the two major substances in many mixtures.
In a water-in-oil emulsion, the water disperses throughout the oil and the oil remains stable or continuous. An oil-in-water emulsion features the water as the stable source and the oil as the disperser. Only constant shaking and stirring may keep the liquids somewhat unified, so many chemists use substances called emulsifiers to facilitate the binding together of the liquids. The type of emulsifier used will often determine which type of basic emulsion results from a mixture. If an emulsifying substance like proteins dissolves more effectively in water, for example, then an oil-in-water emulsion will more likely form.
Various everyday household items are created this way. Food processing frequently uses these processes to create condiment products such as vinaigrette — vinegar and oil — mayonnaise, mustard, and honey. Body lotions and creams found in pharmacies are also emulsions. Many cosmetics makers find the process beneficial as well.
Different degrees of oil and water can create therapeutic balms, creams, pastes, and ointments, which can then be applied for skin treatments. If a product has a highly liquid texture, it can also serve as a medicine administered by swallowing or by injection. In addition, an emulsion can lower the ingredient count of an oral medicine and mask unpleasant odors and thus enhance taste.
A clearer and more stable type called a microemulsion uses oil, water, and substances called surfactants that lower surface tension. Microsemulsions consisting of soybean oil can play an important role in the vaccination process by attacking invading microscopic organisms in the body. Health can also be bolstered if needed nutrients are emulsified and distributed to an immobile patient. As demonstrated, medicine is perhaps the field in which these mixtures have the greatest practical benefit.