Chemistry · Ch 12 — Surface Chemistry
Classification Based on Physical State of Dispersed Phase and Dispersion Medium
12.4.1
Classification Based on Physical State of Dispersed Phase and Dispersion Medium
Since each of the dispersed phase and dispersion medium can be a solid, liquid or gas, eight types of colloidal system are possible. (A gas dispersed in a gas simply forms a homogeneous mixture, so it is not a colloid.) The types, with their common names and examples, are:
| Dispersed phase | Dispersion medium | Type of colloid | Examples |
|---|---|---|---|
| Solid | Solid | Solid sol | Some coloured glasses and gem stones |
| Solid | Liquid | Sol | Paints, cell fluids |
| Solid | Gas | Aerosol | Smoke, dust |
| Liquid | Solid | Gel | Cheese, jellies |
| Liquid | Liquid | Emulsion | Milk, hair cream, butter |
| Liquid | Gas | Aerosol | Fog, mist, cloud, insecticide sprays |
| Gas | Solid | Solid sol | Pumice stone, foam rubber |
| Gas | Liquid | Foam | Froth, whipped cream, soap lather |
Many everyday products and natural objects are colloids — whipped cream is a foam (gas in liquid), fire-fighting foams are colloids, and most biological fluids are aqueous sols in which proteins and nucleic acids are dispersed among ions and small molecules. …
Table 5.4
| Dispersed phase | Dispersion medium | Type of colloid | Examples |
|---|---|---|---|
| Solid | Solid | Solid sol | Some coloured glasses and gem stones |
| Solid | Liquid | Sol | Paints, cell fluids |
| Solid | Gas | Aerosol | Smoke, dust |
| Liquid | Solid | Gel | Cheese, jellies |
| Liquid | Liquid | Emulsion | Milk, hair cream, butter |
| Liquid | Gas | Aerosol | Fog, mist, cloud, insecticide sprays |