Definition

1. Noun (Chemistry, Physics):
   • The substance distributed as particles within a continuous medium in a colloid: In a colloidal system, the "dispersed phase" refers to the component that is broken down into fine particles, droplets, or bubbles and is distributed throughout a different substance. It is the internal, discontinuous phase.

Usage

• The term is used specifically in the context of colloids and mixtures to describe the structure of the system.
• It is often contrasted with the "dispersion medium" or "continuous phase," which is the substance in which the dispersed phase is suspended.

Examples

• Noun:
  • In milk, the fat globules constitute the dispersed phase, and water is the continuous phase.
  • The stability of a colloid depends on the interaction between the dispersed phase and the dispersion medium.
  • Aerosols like fog have liquid droplets as the dispersed phase in a gas.

Advanced Usage

• "Dispersed phase volume fraction": A technical term referring to the proportion of the total volume occupied by the dispersed phase.
  • The viscosity of the mixture increases with a higher dispersed phase volume fraction.
• The concept is central to fields like materials science, pharmaceuticals, and food chemistry for designing emulsions, suspensions, and foams.

Variants and Related Words

• Disperse (verb): To distribute or spread over a wide area; to break up and scatter.
  • The machine is used to disperse the pigment evenly in the oil.
• Dispersion (noun): The process or result of distributing particles within a medium; also used synonymously with "dispersed phase" in some contexts, though "dispersion" more often refers to the entire colloidal system.
  • The dispersion appeared stable under the microscope.
• Continuous phase (noun): The fluid or substance in which the dispersed phase is suspended. Also called the "dispersion medium."
  • In mayonnaise, oil is the continuous phase.

Synonyms

• Internal phase: A less common synonym used in technical contexts.
• Discontinuous phase: Emphasizes that this phase is not connected throughout the mixture.

Related Terms and Concepts

• Colloid: A mixture where one substance of microscopically dispersed particles is suspended throughout another substance.
• Emulsion: A type of colloid where both the dispersed and continuous phases are liquids (e.g., milk, mayonnaise).
• Suspension: A heterogeneous mixture where solid particles are dispersed in a liquid or gas but are large enough to settle over time (technically not a true colloid if particles are too large).
• Aerosol: A colloid where the dispersed phase is solid or liquid, and the continuous phase is a gas (e.g., smoke, fog).

Noun

1. (of colloids) a substance in the colloidal state