Exploring the World of Colloids

Colloids are mixtures where tiny particles are suspended in another medium without dissolving. Think of milk, fog, and jellies. Their unique scattering of light is called the Tyndall effect.

Particles in colloids range from 1 to 1000 nanometers. They're larger than simple molecules but small enough to remain dispersed and keep the mixture stable.

Colloids are diverse: aerosols (fog), emulsions (mayonnaise), foams (whipped cream), sols (ink), and gels (gelatin). Each type has a different dispersed phase and continuous medium.

Unlike solutions, colloidal particles don't settle due to gravity. And unlike suspensions, they don't separate over time, which makes colloids stable yet heterogeneous at the microscopic level.

Surfactants prevent colloids from separating. They reduce surface tension, allowing oil and water, for example, to mix into stable emulsions like lotions or detergents.

Colloids are everywhere: in cosmetics, medicines, food, and paints. They play a crucial role in industrial processes and biotechnologies, often enhancing texture, stability, and delivery of products.

Some colloids exhibit 'non-Newtonian' behavior, meaning their viscosity changes under stress. For example, cornstarch mixed with water becomes solid under pressure, illustrating the complex nature of colloidal mixtures.