Surfactant

Surfactant is a compound that lowers the surface tension between two liquids, between a gas and a liquid, or between a liquid and a solid. Surfactants may act as detergents, wetting agents, emulsifiers, foaming agents, and dispersants.

Types of Surfactants

Surfactants are usually organic compounds that are amphiphilic, meaning they contain both hydrophobic groups (their tails) and hydrophilic groups (their heads). Therefore, they are soluble in both organic solvents and water.

Anionic Surfactants

Anionic surfactants contain anionic functional groups at their head, such as sulfate, sulfonate, phosphate, and carboxylates.

Cationic Surfactants

Cationic surfactants contain cationic functional groups, such as amines and quaternary ammonium cations.

Nonionic Surfactants

Nonionic surfactants have no charged groups in their head. The head of a nonionic surfactant is typically a polyol.

Zwitterionic Surfactants

Zwitterionic surfactants contain a head with two oppositely charged groups. The charge of the head is balanced and does not contribute to the surface activity of the surfactant.

Applications

Surfactants play an essential role in many practical applications and products, including: detergents, fabric softeners, emulsions, soaps, paints, adhesives, inks, anti-fogs, ski waxes, snowboard waxes, de-inking of recycled papers, in flotation, washing and enzymatic processes, as well as in consumer products such as hairsprays, shampoos, toothpastes, shaving foams, some make-up, and bubble baths.

Health and Environmental Concerns

Some surfactants are known to be toxic to the environment and many are not easily biodegradable. Surfactants can also be found in many personal care products and can cause skin irritation and eye irritation.

See Also

• Detergent
• Emulsion
• Foaming agent
• Wetting agent

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  Lipid micelle structure
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  Hydrophilic and hydrophobic parts of a surfactant
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  Gemini surfactant structure
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  Micelle formation scheme
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  Sodium stearate structure
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  Sodium dodecylbenzenesulfonate structure
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  1-Oleoyl-2-palmitoyl-phosphatidylcholine structure