What is micelles? Give one example.

Micelles are clusters of surfactant molecules that form in a solution when the concentration of the surfactant reaches a certain threshold, which is known as the critical micelle concentration (CMC). At concentrations below the CMC, surfactants behave like typical electrolytes. However, as the concentration increases, these molecules aggregate to form micelles, which exhibit unique colloidal properties.

Structure of Micelles

To understand what are micelles in detail, it's essential to look at their structure. Micelles consist of two main components:

• Hydrophilic Head: The hydrophilic head is water-attracting and often carries a charge, making it highly soluble in water.
• Hydrophobic Tail: The hydrophobic tail is water-repelling and typically uncharged, which causes it to avoid contact with water.

How are Micelles Formed?

When surfactants like soap are added to water, individual molecules initially disperse throughout the liquid. However, once the concentration exceeds the CMC, the hydrophobic tails of these surfactant molecules tend to aggregate, seeking to minimize exposure to water. Meanwhile, the hydrophilic heads remain in contact with water, forming a stable structure known as a micelle. This process minimizes the system’s overall energy, creating micelles in the solution.

Example of Micelles

A typical example of micelles can be observed when soap is added to water. In this scenario, soap molecules form micelles where the hydrophobic tails trap grease, oils, and dirt, while the hydrophilic heads interact with the water. This allows dirt and oil to be washed away with water, making soap an effective cleaning agent.

In summary, what are micelles? They are tiny, organized clusters of surfactant molecules that form in a solution when the concentration of surfactant exceeds a certain level. These structures help in cleaning by trapping oil and grease, which can then be removed with water.