There are three general methods of producing colloidally stable dispersions:
Adsorption of a smaller hydrophilic and lypophilic colloid on larger suspended particles: When a strongly hydrated hydrophilic protective colloid (e.g. -gelatin) is adsorbed on the surface of the suspended particles, the affinity for water exceeds the mutual attraction of adjacent particles for each other. Essentially the protective colloid and hydrogen-bonded water molecules form a protective hydration layer around each suspended particle.
Stearic hindrance due to adsorption of an oriented nonionic surfactant or polyelectrolyte: Adsorption of nonionic polymer (gum or cellulosic) or surfactant (polysorbate-80) of sufficient chain length creates stearic hindrance and prevents adjacent suspended particles from coming close enough to join. Stearic stabilization is relatively insensitive than electrostatic stabilization to the presence of added electrolyte.
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