Definition

Noun: A colloidal suspension is a specific type of mixture where solid particles are dispersed and suspended within a continuous liquid phase. The solid particles are typically very small (between 1 nanometer and 1 micrometer in size) and do not settle out quickly due to gravity. This stability distinguishes it from a regular suspension where particles eventually settle.

Usage and Examples

• General Use: The term is used in scientific contexts to describe a stable, heterogeneous mixture.
  • Milk is a common example of a colloidal suspension where fat globules are dispersed in water.
  • The chemist prepared a colloidal suspension of gold nanoparticles for the experiment.

Advanced Usage

• Technical Context: In materials science and chemistry, a colloidal suspension is a system where the dispersed solid phase (the ) and the liquid (the or ) are in different states of matter.
  • The stability of the colloidal suspension is maintained by electrostatic repulsion between the particles.

Variants and Related Words

• Colloid (n): The broader category of mixtures that includes colloidal suspensions, as well as other combinations like aerosols (solid/liquid in gas) or foams (gas in liquid/solid).
• Colloidal Solution (n): Often used interchangeably with "colloidal suspension," though some scientific distinctions exist based on particle size and interaction with the medium.
• Suspension (n): A more general mixture where solid particles are mixed with a liquid but may settle over time (e.g., muddy water).

Synonyms

• Colloidal dispersion: A synonym emphasizing the act of dispersing particles.
• Sol: A specific type of colloidal suspension where solid particles are in a liquid.

Related Phrases and Terms

• Tyndall effect: The scattering of light by particles in a colloidal suspension, which makes a beam of light visible through the mixture. This is a key identifying property.
  • The Tyndall effect is clearly observed when a laser pointer shines through a colloidal suspension.

Noun

1. a colloid that has a continuous liquid phase in which a solid is suspended in a liquid