Suspensions are unstable mixtures of two or more immiscible substances, such as oil and water, that do not dissolve or form a solution. In a suspension, one substance is dispersed throughout the other in small particles that are not evenly distributed. Over time, the particles may settle to the bottom of the mixture, causing the suspension to separate.
These products often contain abrasive particles, such as sugar or salt, that are suspended in a gel or cream base. When the product is applied to the skin, the abrasive particles help to remove dead skin cells and other impurities, leaving the skin feeling smooth and refreshed.
Suspensions can be less stable than other types of formulations, such as solutions or emulsions. If not properly formulated or stored, the particles in a suspension may settle or clump together, causing the product to become ineffective or potentially even harmful. To avoid these issues, it is important to carefully follow the manufacturer’s instructions when using suspension-based products.
There are some differences between suspensions and solutions. Here are some of the differences between suspensions, emulsions, and solutions:
- Homogeneous mixture of two or more substances.
- Solute particles are dissolved in the solvent and cannot be seen with naked eye or microscope.
- Particles are evenly distributed and cannot be separated by filtration.
- Examples include saltwater and sugar in water.
- Mixture of two immiscible liquids.
- One liquid is dispersed in the other in the form of small droplets.
- The droplets are not dissolved and can be seen under a microscope.
- Emulsions are unstable and can separate over time.
- Examples include milk and vinaigrette dressing.
Suspension:
- Heterogeneous mixture of solid particles in a liquid.
- The particles are not dissolved and can be seen with naked eye or microscope.
- Particles settle at the bottom of the container when left undisturbed.
- Can be separated by filtration.
- Examples include muddy water and blood.
| Suspension | Emulsion | Solution |
|---|---|---|
| Particles are too large to dissolve. | Particles are small enough to dissolve, but not evenly mixed. | Particles are small enough to dissolve and evenly mixed. |
| Will settle over time. | Will not settle over time. | Will not settle over time. |
| Cloudy or opaque. | May be cloudy or opaque. | Clear or transparent. |
| May need to be shaken before use. | May need to be shaken before use. | Does not need to be shaken before use. |
| May be unstable and need to be refrigerated. | May be unstable and need to be refrigerated. | Stable and does not need to be refrigerated. |