emulsifikaation

Emulsification is the process of combining two immiscible liquids, such as oil and water, to form an emulsion in which droplets of one phase are dispersed within the other. Because oil and water do not mix spontaneously, energy is usually applied and an emulsifying agent is often used to stabilize the mixture. Emulsifiers reduce interfacial tension and create a protective layer around dispersed droplets, increasing kinetic stability even though the system remains thermodynamically unstable.

Common emulsification methods include mechanical agitation, high-shear mixers, homogenizers, and ultrasonic emulsification. Phase inversion techniques and temperature cycling can also be used to create emulsions with different droplet sizes. Emulsions are categorized by the continuous phase: oil-in-water (O/W) and water-in-oil (W/O). A third class, multiple emulsions (water-in-oil-in-water, etc.) exists for specialized applications.

Emulsifiers used in foods and cosmetics include surfactants such as lecithin, monoglycerides, and polysorbates, as well as natural emulsifiers like proteins. In industrial contexts, solid particles or polymers can stabilize emulsions (Pickering emulsions). Applications span food products (mayonnaise, dressings), pharmaceutical suspensions, cosmetics, coatings, and materials science.

Stability depends on droplet size, interfacial tension, emulsifier type, and storage conditions. Emulsions may separate over time due to coalescence or Ostwald ripening, though appropriate formulation can substantially extend shelf life.