Disperse Systems
1
CHARACTERISTICS OF DISPERSE SYSTEMS
CLASS
Molecular
PART. SIZE
< 1.0 nm
dispersion
CHARACTERISTICS OF SYSTEM
EXAMPLES
▪ Particles invisible in electron microscope
Oxygen molecules,
▪ Pass through ultrafilter and semipermeable membrane
ordinary ions, glucose
Colloidal
1.0 nm to
▪ Particles not resolved by ordinary microscopes, may
Colloidal silver, natural
dispersion
0.5 μm
be detected under ultramicroscope
▪ Pass through filter paper but not semipermeable
and synthetic polymers
membrane
▪ Diffuse very slowly
Coarse
> 0.5 μm up to
▪ Particles visible under microscope
Most pharmaceutical
dispersion
10μm
▪ Do not pass through filter paper or dialyse through
semipermeable membranes
emulsions and suspensions, red blood cells
▪ Do not diffuse
TYPES OF DISPERSE SYSTEMS
DISPERSED
PHASE
Liquid
DISPERSION
MEDIUM
Gas
Liquid aerosol
Fogs, mists, aerosols
Solid
Gas
Solid aerosol
Smoke, powder aerosols
Gas
Liquid
Foam
Foam on surfactant solution
Liquid
Liquid
Emulsion
Milk, pharmaceutical emulsions
Solid
Liquid
Sol, suspension
Silver iodide sol, aluminium hydroxide suspension
Gas
Solid
Solid foam
Expanded polystyrene
Liquid
Solid
Solid emulsion
Liquids dispersed in soft paraffin, opals, pearls
Solid
Solid
Solid suspension
Pigmented plastics, colloidal gold in glass, ruby glass
NAME
EXAMPLES