Disperse Systems: General Characteristics And Classification

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Disperse Systems: General Characteristics And Classification
Disperse Systems: General Characteristics And Classification

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Dispersion systems are colloidal solutions consisting of two or more phases, the interface of which is highly developed. One of the phases consists of small crushed particles, the other is solid. The discontinuous or fragmented part of the dispersion system is the dispersed phase, and the continuous part is the dispersed medium. They do not mix and do not react with each other.

Disperse systems: general characteristics and classification
Disperse systems: general characteristics and classification

Disperse systems and their classification

Dispersion systems can be classified according to the particle size of the dispersed phase. If the particle size is less than one nm, these are molecular ionic systems, from one to one hundred nm are colloidal, and more than one hundred nm are coarsely dispersed. A group of molecularly dispersed systems is represented by solutions. These are homogeneous systems that consist of two or more substances and are single-phase. These include gas, solid or solutions. In turn, these systems can be divided into subgroups:

- Molecular. When organic substances such as glucose combine with non-electrolytes. Such solutions were called true in order to be able to distinguish from colloidal ones. These include solutions of glucose, sucrose, alcohol and others.

- Molecular ionic. In case of interaction between weak electrolytes. This group includes acid solutions, nitrogenous, hydrogen sulfide and others.

- Ionic. Compound of strong electrolytes. Bright representatives are solutions of alkalis, salts and some acids.

Colloidal systems

Colloidal systems are microheterogeneous systems in which colloidal particle sizes vary from 100 to 1 nm. They may not precipitate for a long time due to the solvate ionic shell and electric charge. When distributed in a medium, colloidal solutions fill evenly the entire volume and are divided into sols and gels, which in turn are precipitates in the form of jelly. These include a solution of albumin, gelatin, colloidal solutions of silver. Jellied meat, soufflés, puddings are vivid examples of colloidal systems found in everyday life.

Coarse systems

Opaque systems or suspensions in which small particles are visible to the naked eye. In the process of settling, the dispersed phase is easily separated from the dispersed medium. They are subdivided into suspensions, emulsions, aerosols. Systems in which a solid with larger particles are placed in a liquid dispersion medium are called suspensions. These include aqueous solutions of starch and clay. Unlike suspensions, emulsions are obtained by mixing two liquids, in which one is distributed in droplets into the other. An example of an emulsion is a mixture of oil and water, droplets of fat in milk. If small solid or liquid particles are distributed in the gas, these are aerosols. In essence, an aerosol is a suspension in a gas. One of the representatives of a liquid-based aerosol is fog - a large number of small water droplets suspended in the air. Solid state aerosol - smoke or dust - multiple accumulations of fine solid particles also suspended in the air.

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