How are the colloids formed classified on the basis of
1) Physical states of components
2) Nature of dispersed phase
3) Interaction between Dispersed phase and dispersion medium.
1) Colloidal solutions get classified in 8 Types on the basis of physical state of the dispersed phase and dispersion medium. This are given in following table-
Dispersed phase | Dispersion media | Types of colloids | Example |
Solid | Solid | Solid Sol | Gem stone |
Solid | Liquid | sol | Paints,cell fluid. |
Solid | Gas | Aerosol | Dust,smoke. |
Liquid | Solid | Gel | Butter ,Cheese. |
Liquid | Liquid | Emulsion | Milk,Hair cream. |
Liquid | Gas | Aerosol | Fog,Mist,Cloud. |
Gas | Solid | Solid Sol | Pumice stone. |
Gas | Liquid | Foam | Froth,soap lather. |
2) Depending upon nature of Particles of dispersed phase it can be classified into 3 categories
a) Multimolecular Colloids-In this colloidal particle consist of aggregates of atoms having diameter less than 1nm.
b) Macromolecular colloids-The colloids in which Large particle aggregates and dissolved into suitable liquid.
c) Associated colloids – This colloids show Colloidal property at higher concentrations. This contains ions of colloidal size.
3) Depending upon interactions between dispersed phase and dispersion medium it is divided into 2 categories
a) Lyophilic Colloids- lyophilic (liquid loving) this colloids formed by direct mixing of substances like gum starch etc. with suitable liquid, called as lyophilic sols . This are called as reversible Colloids because if dispersion medium is separated from the dispersed phase it can be reconstructed just by mixing them. This sols are quite stable. Ex-Protein ,Starch.
b) Lyophobic colloids- lyophobic (liquid hating) this Colloids don't formed by direct mixing of dispersed phase and dispersion media they require special methods for preparation. Ex-Sols of metal sulphides .