surfactant
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Definition
Noun: A surfactant is a substance that reduces the surface tension of a liquid it is dissolved in. It is typically a compound with molecules that have both water-attracting (hydrophilic) and water-repelling (hydrophobic) parts, allowing it to interact with both water and oils.
Usage
A surfactant acts at the interface between two different substances, such as between a liquid and a gas or between two immiscible liquids. Its primary function is to lower surface tension, enabling processes like wetting, foaming, detergency, and emulsification.
Examples
- Detergents and soaps are common surfactants that help remove grease from surfaces.
- The surfactant in the shampoo creates a rich lather that cleans hair effectively.
- In the lungs, a natural surfactant prevents the alveoli from collapsing.
Advanced Usage
- Critical Micelle Concentration (CMC): This is the specific concentration at which surfactant molecules begin to form micelles (spherical clusters) in a solution. This is a key property in industrial and chemical applications.
- Surfactant leaching: A phenomenon in paint where surfactants migrate to the surface, often causing a visible glossy or sticky film.
Variants and Related Words
- Surface-active agent: The full technical term for surfactant.
- Detergent: A cleaning agent that contains surfactants.
- Emulsifier: A type of surfactant that helps mix two immiscible liquids, like oil and water.
- Wetting agent: A surfactant that increases a liquid's spreading and penetrating properties by reducing its surface tension.
Synonyms
- Detergent
- Emulsifier
- Wetting agent
- Surface-active agent
Related Phrases
- Anionic surfactant: A surfactant where the hydrophilic part carries a negative charge (e.g., in many laundry detergents).
- Nonionic surfactant: A surfactant with no electrical charge on its hydrophilic part (e.g., often used in cosmetics).
- Biosurfactant: A surfactant produced by microorganisms.
Noun
- a chemical agent capable of reducing the surface tension of a liquid in which it is dissolved