The use of non-ionic surfactants. Surfactants: general information. Watch what is a "surfactant" in other dictionaries

Surfactants (surfactants) are such chemical substanceswhich are capable of concentrating on the borders of the phases and reduce surface (interfacial) tension. Pav is used in pharmaceutical and cosmetics, in the production of shampoos and foaming agents.

Chemical structure of Pav.

The surfactant molecule consists of a hydrophobic hydrocarbon radical and a hydrophilic polar (functional) group, i.e. Diffiral molecule, as a result of which it has a high adsorption capacity. For example, in an emulsion of type "Water / Oil" on the border of the phase section, the hydrophilic group of the Pav molecule is oriented to water, and the hydrocarbon part is to the oil. And the interfacial tension decreases, which provides in water to stabilize the droplets of the oil.

The different effect of sugar esters was observed between gram-positive and gram-negative bacteria. In general, the antimicrobial activity of sugar esters against the gram-positive bacterium was greater than the gram-negative bacterium and mushroom. Gram-negative bacterium was resistant to the inhibitory effects of sugar esters. The essence of esterification of lauroyl sucrose is crucial for antimicrobial activity. Several researchers indicated that di - and trieters do not show antimicrobial activity, probably due to their low water solubility.

The cleaning effect of surfactant is based on the fact that the surfactant ingredients of lotions, shampoos, soaps are adsorbed on the surface of such pollution as fat and solid particles, envelop and facilitate their translation into the washing solution. The surfactant facilitate spreading on the surface of the skin of water or means based on them by reducing the interfacial tension.

The antimicrobial sugar esters reflected the relationship between the molecular structure and antibacterial activity. Duration of chain fatty acids I had a noticeable effect on antibacterial activity. For example, mono esters of sucrose have the same hydrophilic group, but different hydrophobic groups.

Surfactants: harm and benefits

As a rule, the α configuration connection is more efficient than the β-configuration for the same carbohydrate, which was similar to our result. The foaming, foaming stability, the emulsifying ability of oil water and the stability of mono ester emulsion. The results showed that the surface properties of the surface affect the length of the carbon chain, the degree of esterification and hydrophilic groups. Monoesters of the Larath showed best properties as a surfactant.

Types of surfactants

The classification of PAP is based on division depending on the nature of the polar group: non-ionic, non-dissociating in water on ions, and ionogenic, which, depending on the charge-generated during dissociation in water, are divided into: anionic, cationic, amphoteric.

Anionic surfactants when dissolved in water form negatively charged ions with a long hydrocarbon chain (organic anions) and a conventional cation. Anionic surfactants are very effective:

The antimicrobial activity also influenced the length of the carbon chain, the degree of esterification and hydrophilic groups. For mono esters of fatty acids Disaccharide middle length The length of the fatty acid chain is the most important factor affecting surface activity and antimicrobial activity, while saccharide groups and esterification degree are less important.

Soaps emulsify lipoids of skin and remove together with most of the concomitant dirt, descamated epithelium and bacteria, which are then washed off by foam. The antibacterial activity of soap is often strengthened by incorporating certain antiseptics, such as hexachlorofen, phenols, carbanilides or potassium iodide. They are incompatible with cationic surfactants.

when creating emulsions of type "oil / water";
when dispersing a number of powdered materials;
when used in foam detergents To ensure high foaming in rigid water.

As an example of an anionic surfactant, which is often used as part of cosmetic recipes, in particular detergents, it is possible to bring sodium lauriletoxulfate (according to the INCI Sodium Laureth Sulfate). It is obtained by sulfatization of saturated or unsaturated primary higher alcohols, followed by sodium alkali neutralization, ammonia or triethanolamine. It is often produced in the form of a pasty mass containing up to 70% of the main substance.

Cationic detergents are a group of alkyl or aryl-substituted quaternary ammonium compounds with ionized halogen, such as bromide, iodide or chloride. The main site of the action of these compounds seems to be the cell membrane, where they are adsorbed and cause changes in permeability. The activity of old compounds of quaternary ammonium is restored by solid water and porous or fibrous materials that adsorb them. They are also inactivated by anionic substances.

The effect of surfactants on the ecology

Therefore, they have limited value in the presence of clogging of blood and tissues. However, new compounds of quaternary ammonium dialkyl are presumably active in rigid water and are tolerant to anionic residues. Quaternary quarters are mixtures of the fourth generation with the second generation and demonstrate a large biocidal activity in the conditions of high load on the ground, which makes them useful disinfectants in barns and legs. The compounds of quaternary ammonium are effective against most bacteria, shell viruses, some mushrooms and protozoa, but not against non-indexed viruses, mycobacteria and dispute.

Cationic surfactants when dissolved in water form positively charged ions (organic cations) and low molecular weight anion. Cationic surfactants include salts of fatty amines and quaternary ammonium reasons. Cationic emulsifiers, compared with anionic, less effective, as they reduce surface tension less. But they exhibit bactericidal activity, interacting with cellular proteins of bacteria. Cationic surfactants are actively used in hair care products (shampoos, rinsing balms, hair conditioners). Aliphatic cationic surfactants with one and two hydrocarbon tails are good antitags and are used in hair cosmetics.

When applied to the skin, they can form a film under which microorganisms can surrive, which limits their reliability as antiseptics. Oktandine dihydrochloride is a cationic surfactant, which is increasingly used in Europe as an alternative to quaternary, chlorhexidine and iodophoresis for the skin, mucous membrane and wound antiseptics.

These surfactants can be used to solve many common problems associated with formulation, and have great advantages in different applications Due to their unique combination of performance characteristics.

Amphoteric surfactants depending on the pH of the environment behave in alkaline environment As anionactive or in an acidic environment as cationic. In their molecules there are functional groups that are capable of having both negative and positive charge. Such surfactants are well compatible with cationic and anionic. Amphoteric surfactants dermatologically gently act on the skin, so they are often used in children's shampoos "without tears" and means for sensitive skin. For example, in combination with anionic surfactant with sodium lauryl sulfate, it is almost completely softened by its dermatological rigidity. Amphoteric surfactants possess good foaming.

What is a surfactant agent?

Surfactant is a special substance. It reduces the surface tension of the fluid and increases its scattering and wetting properties. Moisturizing hydrophobic surfaces, you can dispel them in the composition on water based. This means that it mobilizes and combines materials such as organic pigments, solvents, binding substances And water that otherwise would not be mixed due to their chemical properties.

It contains two hydrophilic and at least two hydrophobic parts in one molecule, which makes it a more dynamic surfactant than comparable surfactants, only with one hydrophilic or hydrophobic part. Non-ionic, therefore it can be used in anionic or cationic bonding systems. Good wetting abilities due to low migration of surface tension due to the multi-hydrophilic components. The good effect of the defoamation, in contrast to standard non-ionic surfactants, such as alcohol ethoxylates, does not have a poorer point, since the molecule does not form any micelles, giving a clear solution at any temperature, prevents re-agglomeration due to its dispersing properties. Production of paints, production of pigments and dispersions, textiles and cements are also part of this wide range of use.

Bethains are one of the varieties of amphoteric surfactants. They relate to soft and high surfactants. Amphoteric surfactant Cocamidopropylbetaine (Dechiton / Betade) include cosmetics in the production of shampoos, gels and cream gels, liquid soapCleaning Pen for Baths. This surfactant contributes to the compatibility of the cosmetics with the skin, while improves viscosity and foaming of this means. Thus, Dechiton, especially in children's foaming products, is a softening component and contributes to the safety of the use of detergent.

Load our sheet of solutions with standard mixtures and product characteristics. Custom mixtures with different solvents and various percentages can be provided and available on request. Contact our specialist Henry Van der Meer for more information for. As well as surfactants, surfactants are the main cleaning agents in soaps and detergents. These agents are added to flushing water to reduce its surface tension, thereby increasing wetting and propagating properties of water.

Non-ionic (non-ionic) surfactants are surfactant, which, when dissolved in water, do not form ions. They, compared with anionic, having a weaker foaming ability, have a softer effect on the skin. Such surfactants are often used as emulsifiers, dispersants, solubilizers, as well as co-surfactants, foam stabilizers, wetteriers, etc. Diethanolamides of fatty acids can be cited as an example of non-ionic surfactants. Used in the production of shampoos and foaming agents in an amount of up to 3% as a surriving additive, a stabilizer of foam and thickener.

Surfactants usually represent organic compoundswhich are amphilic, which means that they are soluble both in organic solvents and in water. Surfactant agents have two parts, one - hydrophilic, and the other is hydrophobic. Surfactant molecules are concentrated in contact areas or interfaces between oil and water. One end of the molecule is looking for oil, and the other end of the water. When water and oil interacts, the surfactants emulsify the oil and mix it with the liquid as well as fat is mixed in milk.

In Russian-made shampoos to achieve the necessary consumer properties And quality improvements are used by various combinations of surfactants, depending on the purpose of the cosmetics.

PAV, used in the cosmetic industry, must correspond to a single sanitary-epidemiological and hygienic requirements To the goods subject to sanitary and epidemiological surveillance (control).

At the boundary of the water, these agents capture air molecules to obtain foam. Due to the reduction of surface tension of water, surfactants improve the cleaning efficiency, allowing the solution to the surface quickly and efficiently, and, therefore, the soil can be easily loosen and removed. Surfactants also emulsify oil soils and retain them weighted and dispersed so that they do not set out on the surface. To achieve excellent cleaning characteristics, most cleaning products contain two or more surfactants.

Advantages of using surfactant:

lead to stabilization of the dispersed system, the adhesion and coagulation of the particles of the dispersed phase are impossible;
facilitate the process of dispersing and obtaining cosmetic compositions;
improve wettability and spreadability of cosmetic substances on the skin;
ensure the stability of reverse emulsions;
in the composition of foaming agents improve their foaming and increase the stability of foam when used.

Literature

Types of surface active agents

Anionic surfactants non-ionic surfactants cationic surfactants amphoteric surfactants. Self-collecting is the tendency of surfactants to organize and coordinate in the extended structures in water. The process includes the formation of micelles, liquid crystals and bislows, which are formed when hydrophobic tails of surface-active substances molecules are combined together to produce small units, such as micelles, or large layer structures, such as bisloe, similar to the cell wall.

Surfactants and compositions. Directory. Edited by M.Yu.Pletneva 2002. - P.40-44.

Basics of cosmetic chemistry. Basic positions and modern ingredients. Ed. Puchkov T.V. 2011, p.122-133.

Explanatory dictionary of cosmetics and perfumery T.1 Finished products 2nd ed. 2004. C.20.

Surfactants have a polar (asymmetric) structure of molecules, capable of adsorbing on the border of two environments and lower the free surface energy of the system. Completely minor additives of surfactants can change the properties of the particle surface and give the material new qualities. The action of the surfactant is based on the adsorption phenomenon, which simultaneously leads to one or two opposite effects: reducing the interaction between particles and stabilizing the surface of the section between them due to the formation of the interfacial layer. For most surfactants, the linear structure of molecules is characteristic, the length of which significantly exceeds the transverse dimensions (Fig. 15). Molecules radicals consist of groups related by its properties of solvent molecules, and from functional groups with properties, sharply different from them. These are polar hydrophilic groups, possess sharply pronounced valences and have a certain effect on wetting, lubricating and other actions associated with the concept of surface activity . This reduces the supply of free energy with heat release as a result of adsorption. Hydrophilic groups at the ends of hydrocarbon non-polar chains can be hydroxyl - it, carboxyl - coxy, amino - nn 2, sulfo - SO and other strongly interacting groups. Functional groups are hydrophobic hydrocarbon radicals characterized by side valence bonds. Hydrophobic interactions exist independently of the intermolecular forces, being an additional factor contributing to rapprochement, "sticking" of non-polar groups or molecules. The adsorption monomolecular layer of pump molecules with free ends of hydrocarbon chains is focused on

These characteristics of surfactants make them interesting research and research area. Surfactants can also be organized for the formation of micelles, which allows hydrophobic tails to get out of the water, but it still allows hydrophilic heads to remain in water. As a rule, from several tens to several hundred surface-active substance molecules in a micelle.

Watch what is a "surfactant" in other dictionaries

When the micelles are formed in water, their tails form the core, which can encapsulate the oil drop, and their heads form an outer sheath, which supports a favorable contact with water. When surfactants are collected in oil, their unit is mentioned as reverse micelle. In reverse micelles, the head remains in the kernel, and the tails support favorable contact with oil.

the surface of the particles and makes it unmatched, hydrophobic.

The effectiveness of this or that additive additive depends on physico-chemical properties material. The surfactant, which gives the effect in one chemical system, may not have any action or obviously the opposite - to another. At the same time, the concentration of surfactant is very important, determining the degree of saturation of the adsorption layer. Sometimes an action similar to the surfactant exhibit high molecular compounds, although they do not change the surface tension of water, for example, polyvinyl alcohol, cellulose derivatives, starch and even biopolymers (protein compounds). The action of surfactants can have electrolytes and substances insoluble in water. Therefore, it is very difficult to determine the concept of "surfactant". In a broad sense, this concept refers to any substance that in small quantities changes significantly changes the surface properties of the dispersed system.

The use of surface active agents

The thermodynamics of surfactant agents is of great importance both theoretically and practically. This is due to the fact that these agents are systems between ordered and disordered states of the substance. The surface-active substance industry is obliged to their dynamic development of the orientation of manufacturing enterprises to the development and development of innovative products that can be used both in the production of consumer goods and in production processes.

The surfactant classification is very diverse and in some cases contradictory. Multiple attempts have been taken by classification by different features. On the Rebinder, all surfactants are divided into four groups on the mechanism:

- wetting agents, defoamers and foaming agents, i.e., active liquid-gas on the interface. They can reduce the surface tension of water from 0.07 to 0.03-0.05 J / m 2;

Already started and planned investments allow us to gradually expand the offer of innovative products that are developed in accordance with the current trends and requirements of customers. Surfactants are chemical surfactants with a specific structure that reduce the surface tension of the fluid. This property gives surfactants to their versatility and the ability to use them in almost every industry.

Advantages of using Peav.

Due to its function that they perform in the appropriate recipes of products or production processes. Surfactants can be divided into the following groups. Surfactants used in the production of cleaning and cosmetic products. Surfactants for industrial applications. . The basic groups mentioned above relate to products of various products. chemical structurewhich are divided into the following subgroups.

- dispersants, peptizers;

- stabilizers, adsorption plasticizers and dilutes (viscosity slides);

- Detergents with all properties of surfactants.

Abroad is widely used classification of surfactant for functional purposes: dilutes, wetting agents, dispersants, defloculants, foaming agents and defoamers, emulsifiers, stabilizers of dispersed systems. Aloams also binders, plasticizing and lubricating substances.

According to the chemical structure of Pav, it is classified depending on the nature of hydrophilic groups and hydrophobic radicals. The radicals are separated into two groups - ionogenic and non-ionic, the first can be anion and cationic.

Non-ionic surfactants contain non-ionizing finite groups with high affinity for the dispersion medium (water), which include usually oxygen, nitrogen atoms, sulfur. Anionactive surfactant - compounds in which a long hydrocarbon chain of molecules with low affinity for a dispersion medium is part of an anion formed in an aqueous solution. For example, the coxy is a carboxyl group, SO 3 H - sulfugugroup, OSO 3 H - a group of ether, H 2 SO 4, etc. To anionactive surfactants include carboxylic acid salts, alkyl sulfates, alkyl sulfonates, etc. Cationic substances form B. aqueous solutions Cations containing a long hydrocarbon radical. For example, 1-, 2-, 3- and 4-substituted ammonium and others. Examples of such substances may be salts of amines, ammonium bases, etc. Sometimes they allocate the third group of surfactant, which includes amphoteric electrolytes and ampholite substances that depend on The nature of the dispersed phase can be exhibiting both sour and basic properties. Ampholites are insoluble in water, but active in non-aqueous media, such as oleic acid in hydrocarbons.

Japanese researchers offer classification of surfactant for physico-chemical properties: molecular weight, molecular structure, chemical activity, etc. arising from the surfactant gel-like shells on solid particles as a result of various orientation of polar and non-polar groups can cause a variety of effects: discharge; stabilization; dispersion; foaming; Binding, plasticizing and lubricating actions.

The positive effect of the surfactant has only at a certain concentration. On the issue of the optimal number of imposed surfactants, there are very diverse opinions. P. A. Rebelder Indicates that for particles

1-10 microns required amount Pav should be 0.1-0.5%. Other sources are given 0.05-1% and more for different dispersion. For ferrites, it was found that for the formation of a monomolecular layer during dry oil, the surfactant must be taken at the rate of 0.25 mg per 1 m 2 of the specific surface of the initial product; For wet grinding - 0.15-0.20 mg / m 2. Practice shows that the concentration of surfactants in each particular case should be seized experimentally.

In the Ceramic Rem technology, you can select four directions for the use of surfactants, which allow you to intensify physico-chemical changes and transformations in materials and manage them in the synthesis process:

- intensification of the processes of fine grinding of powders to increase the dispersion of material and reduce the grinding time when the specified dispersion is reached;

- regulation of the properties of physicochemical dispersed systems (suspensions, shrackers, pastes) in technological processes. Here the processes of liquefaction (or lowering viscosity with increasing fluidity without decreasing moisture content), stabilization of rheological characteristics, foaming in dispersed systems, etc.;

- control of the processes of flare formation in spraying suspensions when obtaining the specified sizes, form and dispersibility of the torch sprayed;

- an increase in the plasticity of the molding masses, especially obtained when exposed to elevated temperatures, and the density of manufactured billets as a result of the introduction of a complex of binders, plasticizing and lubricating substances.