Products
Emulsifiers are available as pure substances, for example, in pharmacies and drugstores. They are found in numerous pharmaceuticals, cosmetics (personal care products), medical devices and foods.
Structure and properties
Emulsifiers are amphiphilic, meaning they have both a hydrophilic and lipophilic structural character. This allows them to mediate between the water and fat phases. Emulsifiers are divided into ionogenic (cation-active, anion-active and amphoteric) and non-ionogenic (neutral) representatives. Depending on the emulsion formed, a distinction can be made between oil-in-water and water-in-oil emulsifiers.
Effects
Emulsifiers are interfacially active, i.e. they lower the interfacial tension. As a result, they enable the production of emulsions.
Areas of application
- For the preparation of emulsions.
- For the production of foams.
- For the mediation between water and fat.
- For cleaning and stain removal (as surfactants).
Examples
- Alkali soaps such as sodium stearate and sodium palmitate.
- Arabic gum
- Bentonite
- Carrageenan
- Celluloses such as the methyl cellulose
- Cetyl alcohol
- Cetylstearyl alcohol
- Cholesterol
- Emulsifying cetylstearyl alcohol
- Gelatin
- Glycerol monostearate
- Laureth-2
- Laureth-4
- Lecithin (e.g. egg yolk, soy)
- Magnesium stearate
- Macrogol stearate
- Milk proteins and other proteins
- Mono- and diglycerides of fatty acids (E 471)
- Sodium cetylstearyl sulfate
- Sodium lauryl sulfate (SLS)
- Oleyl alcohol
- Phospholipids
- Poloxamers
- Polysorbates (e.g. polysorbate 20, 40, polysorbate 60, polysorbate 80).
- Sucrose esters such as sucrose monopalmitate.
- Sorbitan monolaurate (Span 20)
- Sorbitan monopalmitate (Span 40)
- Sorbitan monostearate (Span 60)
- Sorbitan monooleate (Span 80)
- Stearyl alcohol
- Triethanolamine (with fatty acids)
- Wool wax, wool wax alcohols, lanolin
- Xanthan gum
Adverse effects
Emulsifiers have a bad reputation among the public similar to other additives. For example, they are associated with the development of gastrointestinal diseases and they can cause allergic reactions. There is evidence in the scientific literature of possible negative effects. It must be noted that emulsifiers are a very heterogeneous and diverse group of molecules. General statements on compatibility are therefore difficult. Many natural substances are also effective as emulsifiers.