Coacervation

Coacervation (from Latin coācervāre - to collect, accumulate) is a set of processes leading to the formation in a solution of a more concentrated complex of particles than the original solution. The coacervate differs from the environment in the concentration of components and the properties of the phase interface. Coacervates can be obtained as a result of mutual coagulation of two or more solutions, as well as as a result of condensation of vapors of one substance on the surface of drops of another substance.

Coacervation can be considered a reversible process, but in the case of coagulation that results in sediment formation, it is an irreversible process. Coacervations are observed in various systems, for example, in dilute electrolyte solutions, in colloidal systems, etc.

In dilute solutions, coacervation can occur when electrolytes are added to them. In this case, complexes of ions with water molecules are formed, which then combine into larger particles. This process is called ion hydration.

In colloidal solutions, coacervation can also occur. In this case, larger particles are formed, called colloidal particles. These particles can be formed from polymer molecules or from a mixture of various colloids.

One example of coacervation in nature is the formation of raindrops from water vapor in the atmosphere. In this case, steam condenses on dust particles, forming droplets of water, which then fall to the ground.

Thus, coacervation is an important process that occurs in various systems. It can be used to obtain more concentrated solutions or to form larger particles in colloidal systems.

Coacervation (reminder, play on the term, coacerulation - lat. coaservationis gathering) is the gradual association of proteins, ions and colloids into larger complexes. The appearance of coacervation is possible due to strong electrical charges on the surface of colloidal particles. Cations are directed towards negatively charged particles, and anions - towards positively charged ones. But since there are more anions than cations, the electrostatic forces of attraction between positively charged particles prevail over the repulsive forces between cations. As a result of these mutual attractions, aggregates of colloidal particles are formed. Since the colloidal particle retains its electrical activity, a flow of charged ions directed towards the surface of the aggregate is created between its charged residues and the aggregation sphere. This gives the unit additional positive or negative charges. In addition, charged ions are adsorbed and create spherical aggregates. The larger the surface area of ​​the aggregates, the easier it is to combine them. At each stage of coacerate formation, the process continues until such a ratio is reached between the positive surface charges of the particle and the negative charges of the surface ions, at which the resulting charge on each part