Surfactants - compounds which affect the surface tension.In the process of interaction between the molecules of the liquid formed between them traction.This force will be different in surface and internal (deep) layers.Considering the state of the liquid is easy to establish that the particles are directed into the system from different sides are surrounded by the molecules that affect them.The resultant of all the forces that act on a molecule is zero.Therefore, the liquid surface are smallest for a given volume.This is clearly manifested in the form of spherical droplets.The presence of impurities of various compounds in the fluids causes the surface tension.
structure of surfactant molecules
particles of fatty acids and alcohols are made up of two parts which have different properties, therefore these compounds is often referred to diphilic structures.One part of the molecule represented hydrocarbon chain, and the other - different functional groups (amino, hydroxyl, carboxyl, sulfo).The longer the hydrocarbon chain, the more pronounced will be the hydrophobic properties of the particles, they will interact with less water.
Surface active agents (surfactants) are known: the bile acids, proteins, soaps, alcohols, ketones, aldehydes, tannins, ketones, etc.Surface-inactive substances do not affect the surface tension (starch, glucose, fructose).
nonionic surfactants (nonionic surfactant) - High biosoedineniya which in water form ions.The reservoirs these substances act together with industry (chemical, textile, oil industry), household (using a variety of synthetic detergents in everyday life) sewage and with sewage waste from agricultural land (herbicides, fungicides, insecticides, as well as tomes inas emulsifiers).
Surfactants are finding many uses in the economy.In the agricultural sector, they are used for the preparation of emulsions and wettable powders in the practice of protecting plants from pests.Conducts research on the use of surfactants to reduce water evaporation from the soil surface.If you water the soil mixtures with the composition formed on the surface of ultra-thin film that prevents the evaporation of moisture, but at the same time it is perfectly breathable and precipitation.If processed fruits and vegetables surfactant solution, they are a long time remain juicy and fresh.When adding surfactant to the feed increased weight gain of birds and animals by approximately 20% compared to control animals.
Surfactants: harm and benefit
surface tension is of great importance for the processes of absorption of nutrients in the intestine.For example, fats and lipids in the digestive tract comes in the form of droplets.Recent emulsified in the small intestine by means of bile acids.Only after these fats are hydrolyzed lipolytic enzymes.Very often, to improve the efficiency of insecticide added to the soap (surfactants).Manipulations insecticides allows better interact with the body surface of insects.However, surfactants have not only positive but also negative effects on the organism.For example, included in the shampoo is very harmful foaming agents (surfactants), such as sodium and ammonium lauryl sulfate, ammonium and sodium laureth sulfate.It is believed that these components have carcinogenic impact.
