What role do surfactants play in cosmetics?

Surfactants play a crucial role in cosmetics by enabling substances to emulsify, which means they help to mix two typically immiscible liquids, such as oil and water. This is important in many cosmetic formulations where a stable blend is required for effective application and performance. Surfactants lower the surface tension between the liquids, allowing them to blend seamlessly.

In addition to their emulsifying properties, surfactants can also serve as cleansers, aiding in the removal of dirt, oil, and impurities from the skin. Their ability to stabilize emulsions is essential for creating products like lotions, creams, and other formulations that require a homogenous mixture for optimal use and sensory experience.

The other options provided, such as providing fragrance or acting as a preservative, are separate functions not directly related to the emulsifying characteristic that surfactants offer.