📖 Theory & Concepts ▼

What are Emulsions?

Emulsions are colloidal systems where both dispersed phase and dispersion medium are liquids (immiscible).

Oil-in-Water (O/W)

Oil droplets dispersed in water. Water is continuous phase.

Examples: Milk, Vanishing cream, Cod liver oil

Water-in-Oil (W/O)

Water droplets dispersed in oil. Oil is continuous phase.

Examples: Butter, Cold cream, Margarine

Emulsifying Agents

  • Soaps & Detergents: Stabilize O/W emulsions (hydrophilic head outward)
  • Proteins: Casein in milk, Egg yolk (lecithin)
  • Gums: Arabic gum, Tragacanth - natural stabilizers
Identification Tests:

• Dye Test: Water-soluble dye colors O/W uniformly, W/O shows droplets

• Dilution Test: O/W dilutes with water, W/O dilutes with oil

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Oil-in-Water (O/W)

Water is continuous phase
Oil droplets dispersed in water
Examples:
Milk, Mayonnaise, Face cream
🛢️

Water-in-Oil (W/O)

Oil is continuous phase
Water droplets dispersed in oil
Examples:
Butter, Cold cream, Cod liver oil

🧪 Identification Tests

Lab Notebook

Shake emulsions to begin...