Emulsion - a liquid mixture

Emulsion - a mixture of substances.It consists of one component of the smallest particles which are insoluble in one another.This ingredient is called "dispersed phase".Another matter - dispersion medium.It distributed the first component."Emulsion" - a term that has a Latin origin.Translated, it means "to milk, milk the".Consider this concept in more detail.

General

of any two liquids that do not mix and do not react chemically, can make an emulsion.One of the components is almost always water.Another matter consists of weakly polar or neutral molecules (such as fats).The first known all emulsion - is milk.Here the fat particles dispersible in water.The size of the smallest particles of the dispersed phase is 1-50 microns are so coarse emulsion systems.Low-concentration liquid - unstructured.Mixtures with a high concentration - structured.On thermodynamic grounds oil emulsion - is an unstable system.Dimensions have large droplets phase, and the mixture is unstructured.

Classification

an emulsion type depends on the volume ratio of the phases and their composition, the amount and nature of the emulsifier, its chemical activity, the method and the method of mixing.

1. direct admixture with the smallest particles of the nonpolar liquid and insoluble in the polar phase (o / w - the expression "oil in water").For such mixtures of emulsifiers may be used which are soluble in water, such as particles of bitumen.These molecules are adsorbed on the surface films of m-phase, reducing not only the tension but also creating durable film.
2. Inverse (V / m) mixture, which is used for water-insoluble emulsifier.

Chemical effects on the emulsion, the pressure change in the composition can lead to inversion.

1. Freeze Emulsion - a mixture that is formed spontaneously, spontaneously.It is considered to be thermodynamically stable.An example is critically stable emulsions when the limit for the mixing phase temperature.This category also includes lubricating oils and liquid cooling.
2. lyophobic emulsion - a mixture formed by mechanical, acoustic or electric mix.They are thermodynamically extremely unstable.Such mixtures without emulsifiers do not exist for a long time.Good components including: surfactants, high molecular weight, water soluble substances with a high solids dispersion.

Getting

There are two technologies of production of emulsion.The first - the way fine crushing factions.The second - the process of film formation, followed by a break into small pieces.In the first embodiment, the substance is slowly added to the dispersed system.This requires implementing the accession constantly at high speed stirring.In this case, the quality of the mixture will depend on various factors.In particular, on the stirring rate of administration and amount of dispersible material, its concentration, the temperature and acidity.The second method - a process in which a film is formed on the surface of another phase.Bottom blown air.Bubbles tear film into small drops and stirred the whole volume of liquid.In our time, we started to use ultrasound instead of air.This causes the splitting of the film into even smaller pieces.

Destruction blends

Over time, there is a spontaneous breaking of the emulsion.There are times when you need to speed up the process and reduce the concentration of compound.This urgent need, where the presence of highly concentrated emulsions hinders the process of processing the material or its correct use.To accelerate the process of reducing the concentration of the solution in several ways:

1. chemical method.The reagents, destroying the surface of the film of the emulsifier.This negative charge, concentrating on the surface film is neutralized.On the same principle, the use of organic additives based dietary supplements (biologically active substances - demulsifiers).
2. added emulsifiers, causing the formation of cations that attract negative surface charge and cause destabilization of surface films of the emulsifier.The stability of the state of the solution decreases.
3. Substitution emulsifier other surface-active component (PAVom).It dilutes the concentration of the first, but did not form a sufficiently strong film.
4. thermal methods.In this method, the emulsion is subjected to thermal effects, which causes its bundle.
5. mechanical method.This version is also called the way of the separator.The emulsion is slowly pumped into the rotating angular velocity with great capacity.The solution breaks into components by weight fractions.
6. method electric shocks or adding electrolyte to the emulsion.This method destroys the stabilized negative charge surface film blends.

Application The range of applications of emulsions in the industry is very wide.In particular, the compounds are used:

1. In the production of margarine and butter.
2. in soap.
3. In the manufacture of materials made of natural rubber.
4. in construction.For example, bitumen emulsion - is a non-flammable compound.
5. in agriculture: pesticides - a variety of drugs that destroy plant pests.
6. for medical purposes: izgotolvenie different medications, ointments, cosmetics.
7. In painting using different emulsion paints.
8. Hair cosmetics, emulsion, protects the surface of the hair when painting.For example, showing the emulsion (this oxidant paint).
9. The oil industry uses a mixture of water with oil in which the dispersion of one liquid phase into another takes small droplets - globules.