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Amphoteric surfactants: what they are made of, types, classification, principle of action, additives in household chemicals, pros and cons of use

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Amphoteric surfactants: what they are made of, types, classification, principle of action, additives in household chemicals, pros and cons of use
Amphoteric surfactants: what they are made of, types, classification, principle of action, additives in household chemicals, pros and cons of use

Today there are two opinions. Some say that amphoteric surfactants are harmful substances that should not be used. Others argue that it is not so dangerous at all, but their use is necessary. To understand why this dispute arose, it is necessary to understand what these components are.

General Description

It is worth starting with the fact that the addition of amphoteric surfactants to shampoo, for example, is simply necessary. The thing is that if you wash your hair only with water, you will be able to remove only those contaminants that can be dissolved in water. Dust, dirt and sweat do not dissolve in the usual liquid, but, on the contrary, will create strong bonds with skin lipids. Because of this, the application of chemicals is necessary to remove such substances from the skin, hair.

Today there are 4 types of surfactants that differ from each other by the polarity of their molecules. On this basis, anionic, cationic, nonionic or amphoteric are distinguished. It is worth noting thatsome call the amphoteric group still ionic. Because of this, there are problems, since people believe that there are 5 such groups - amphoteric surfactants, ionic and others. However, this is not the case and there are only 4 of them.

set of medical supplies

Description of the first category

This species includes anionic and cryptoanionic sulfo compounds. In addition, these substances belong to tensides, which are most strongly incompatible with dirt among others. And it is this chemical that most of all those who oppose the use of surfactants complain about. However, if you look at things from a practical point of view, then this group is the best additive to any detergent. Anions and cryptoanions most effectively remove dirt from surfaces they come into contact with. For this reason, today almost all effective detergents contain such an additive.

organic cream with surfactant

Getting and using

It's worth noting right away that it was this group that people learned to receive first of all. With the passage of time and the development of mankind, it was possible to obtain anionic tensides from proteins and fats alkalized with ash and other compounds of this type. To date, the main source of raw materials for the production of anionic and cryptoanionic surfactants is coconut, palm, rapeseed oil, as well as oil from cow or goat milk.

As for the principle of operation of this category of surfactants, it is based on the special structure of the molecules of this group. The thing is that they consist of two parts - hydrophilicand hydrophobic. One of them (hydrophilic) loves water, the other, on the contrary. The first part of the molecule allows the substance to come into contact with water and be washed off by it. The second part, on the contrary, comes into contact with non-polar substances, that is, dust, dirt, fats, and so on. During shampooing, for example, hydrophobic parts capture dirt and other similar substances into a micelle - a hollow ball. So it turns out that while washing off the shampoo with water, all impurities are also removed.

From the main advantages of this group stands out the rapid, high-quality and complete removal of dirt from the surface of the skin, as well as appendages. In addition, the molecules are capable of foaming, have bactericidal and bacteriostatic properties.

gel with additives

Amphoteric and non-ionic groups

All manufacturers of quality products that contain anionic surfactants understand that it is necessary to soften their action on the human lipid mantle as much as possible, but at the same time not to reduce their cleansing effect. It is to solve this problem that amphoteric surfactants are used. Some also refer to the nonionic and amphoteric group as cosurfactants.

This group of tensides is designed to neutralize the acid reaction of anions. In addition, they also contribute to the rapid breakdown of these substances, as well as compact and reduce the airiness, that is, the diameter of the foam bubbles.

It is worth saying that the types of amphoteric surfactants are the most expensive representatives among all products. To obtain this substance, it is necessarycarry out the procedures of squeezing, extraction, infusion, rectification and oxidation of natural substances. Both plant and animal raw materials are suitable for obtaining the substance. There are some of the most famous and common products that are used to extract these supplements. Amphoteric surfactants are obtained from soapwort, algae, apple pulp, root vegetables, palm oil and dairy products.

surfactant detergent

The principle of action of the amphoteric group

To understand the importance of adding amphoteric surfactants, you need to have at least the slightest understanding of chemical processes. It is known that oppositely charged substances will be attracted to each other in pairs, because of which their relationship will decrease, and they themselves will precipitate. All this will lead to the fact that the cleansing effect will drop significantly. It was possible to solve this problem by introducing amphoteric surfactants.

Their principle of operation is based on the fact that they are able to easily give away or attach an electron pair of the environment in which they are located. In other words, in an acidic environment, they are able to change their properties. If you place them in an alkaline environment, they will act as anions, and in an acidic environment they will play the role of cations.

vegetable oil cream

Properties of matter

In cosmetics, amphoteric surfactants are needed to protect the skin and hair from dryness and irritation. In addition, tensides of this group are able to restore the stratum corneum of the epidermis, hair keratin, soften, and also increaseconnective tissue elasticity.

raw material for obtaining vegetable surfactants

Nonionic Compounds

As mentioned earlier, there are no more than 4 types of basic surfactants. Nonionic surfactants, amphoteric surfactants are two different categories, but amphoteric surfactants are also ionic, which is about the same thing. Ionic substances are those substances, after the dissolution of which these same ions remain. In other words, non-ionic surfactants are the only group among others, after the dissolution of which no ions are formed. Fatty alcohol esters such as polyglycol and polyglycol esters fall into this category. This group includes, for example, feistenside - a liquid with good fluidity, which consists of citric acid and fatty alcohols.

In order to obtain such additives, it is necessary to carry out the procedure of oxyethylation of vegetable oils. Castor oil, wheat germ, flax, sesame, calendula, parsley became the main raw material for obtaining the non-ionic group. One of the key features of this group is that they can exist in either liquid or paste form. That is, solid detergents (soap, powder) cannot contain such products.

With regard to the use of this group of surfactants, esters are a substance such as a dispersion micellar solution. Very often it is also called "smart soap". The essence of the name is revealed by the fact that the detergent is able to remove dirt and grease from the surface of the skin or hair without damaging the protectiveskin mantle.

structure of surfactant molecules

If we talk about the properties of the non-ionic category of substances, they can increase the safety, environmental friendliness and softness of the composition. The biological degradability of this group of tensides is 100%. Able to activate therapeutic additives that may be contained in a hair cleanser, can restore damaged layers of the epidermis, have a bradykinase and polishing effect.

Are amphoteric additives harmful?

Naturally, many are interested in the question of what harm amphoteric surfactants do to human skin and he alth in general. Here it is immediately worth saying that if you look at the reverse side of the effects of all surfactants, then the amphoteric group is the safest among them.

Description of the effects of the amphoteric category on humans

To start with, the lather produced by these particular surfactants is the most moderate, and it can also improve the quality of the hair. In addition, amphoteric additives themselves cause minimal irritation of the scalp, but at the same time they are able to relieve irritation caused by other substances, and can be more severe. If you combine amphoteric tensides and anionic tensides, you can achieve improved foaming, as well as reduce the harm to the recipe for the skin. If you combine this group with cations, then you can significantly improve the conditioning products, which will positively affect the he alth of the skin and hair.

If we talk about detergents, then they contain amphoteric productsalso found quite often, but in the form of a supplement of betaine. To get just such components for detergent, you have to use fatty acids of coconut, soy, sunflower oil. In addition, the idea that amphoteric surfactants will harm humans can be changed by adding it to children's shampoo. This is due precisely to the fact that the substance is rather harmless, and if it gets on the cornea of ​​the eye, it does not cause irritation.

Harming other groups

Some believe that the anionic group is quite dangerous for humans. And moreover, the danger lies precisely in what they are added to the composition for, that is, they remove fats too diligently, while degreasing the skin. This leads to the destruction of the hydrolipidic film, damage to skin lipids and penetration of surfactants into deeper layers. The balance of microflora may be disturbed, and a violation of the mechanisms responsible for physiological fat formation is also possible. It can be said that the skin dries out too much under the influence of anions, which is why it ages faster.

It is also noted that this group of surfactants may accumulate in the heart, brain, liver, and especially in body fat. Getting into these places, anionic surfactants continue to destroy the body from the inside, and this process lasts quite a long time. It is also capable of interfering with the metabolic functions of the body.

All this leads to the fact that there is a need to neutralize such consequences. It is for this that the amphoteric group of surfactants is abundantly used, despite the fact that theythe most expensive.


Summing up all of the above, we can draw one conclusion. Natural resources are used to produce any surfactant. However, if you do not follow the rules of mixing or consistency, or do not add, for example, amphoteric surfactants, then detergents can be harmful.

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