Coacervatie

Coacervatie, or coacervation, is a type of liquid–liquid phase separation that occurs in polymer solutions and colloidal suspensions. It leads to the formation of a polymer-rich dense phase, the coacervate, which separates from a polymer-poor supernatant. The process creates micron- to submicron-sized droplets that can be manipulated for various applications.

There are two main forms. Complex coacervation occurs when two oppositely charged polymers, or polyelectrolytes, interact and demix to form a dense coacervate phase. Simple or true coacervation involves a single polymer system, where phase separation is driven by changes in solvent quality, temperature, or ionic strength. In both cases, the driving forces include electrostatic attraction, hydrogen bonding, and entropy gains from the release of counterions during droplet formation.

The outcome depends on factors such as pH, ionic strength, temperature, polymer charge density, molecular weight, and the relative concentrations of the components. Natural and synthetic polymers commonly used include gelatin, gum arabic, alginate, carrageenan, pectin, and chitosan. The resulting coacervates are typically fluid and can be stabilized or solidified by physical or chemical crosslinking.

Applications span encapsulation and controlled release technologies. Coacervates are used to entrap flavors, fragrances, essential oils, vitamins, drugs, and other bioactives, protecting them from degradation and enabling targeted delivery. In food, pharmaceutical, and cosmetic industries, coacervation supports microencapsulation, texture modification, and controlled release. The method is studied for its mechanisms, optimization, and potential environmental and scalable production benefits.