Definition and types of colloidal solutions

A colloidal solution is a heterogeneous mixture where one substance (the dispersed phase) is evenly dispersed in another substance (the dispersion medium). The particle size in a colloidal solution ranges from 1 to 1000 nanometers.

Based on the dispersion medium and dispersed phase, colloidal solutions can be classified into various types:

• Sol: Solid particles in a liquid medium (e.g., paint, muddy water).
• Gel: Liquid particles in a solid medium (e.g., jelly, cheese).
• Foam: Gas particles in a liquid or solid medium (e.g., whipped cream, foam rubber).
• Aerosol: Liquid or solid particles in a gas medium (e.g., fog, smoke).
• Emulsion: Liquid particles in another liquid medium (e.g., milk, mayonnaise).