How are colloids classified on the basis of
Physical states of components
Nature of dispersed phase and
Interaction between dispersed phase and dispersion medium ?
(1). Depending upon the physical state of dispersed phase and dispersion medium whether these are solids, liquids or gases, eight types of colloidal systems are possible. For example Solid sol, Emulsion, solid foam, Aerosol, etc.
(2). On the basis of nature of dispersed phase, colloids are classified as :
(a) Multimolecular colloids, e.g., gold sol, sulphur sol etc.
(b) Macromolecular colloids, colloids, e.g., cellulose, starch, etc.
(c) Associated colloids, e.g., soaps, synthetic detergents.
(3). On the basis of the interaction between the dispersed phase and the dispersion medium, colloids are of two types :
(a) Lyophilic colloids, e.g., gum, gelatin etc.
(b) Lyophobic colloids, e.g., metals, their sulphides etc.