These are multifunctional substances with a unique structure, used both in industry and in everyday life. Due to the wide range of applications of these compounds, the surfactant market is an important sector of the economy in Poland and the world.
What are surfactants?
The word surfactant is derived from “surface active agent“. The other name for surfactants is tensides. This name comes from the Latin word tensus, which means “tight”, and characterizes the ability of surfactants to reduce surface tension.
What is the structure of surfactants?
Surfactants are characterized by amphiphilic molecular structure. This term is related to the word amphi, which in Greek means both types, both sides. These compounds contain two extremely different parts in their structure. The first, called the “head” – hydrophilic, is composed of polar groups, while the second is a non-polar, hydrophobic tail.
The hydrophilic head of the surfactant may be polar groups that have a strong affinity for water. It is, among others, a hydroxyl, carboxylic, sulfate, sulfone or oxyethylene group. The hydrophobic fragment is hydrocarbon chains. The tail can have a different structure and length depending on the amount of carbon atoms it contains. The surfactants contain straight, branched chains and also chains that have aromatic rings.
What are the properties of surfactants?
When dissolved or dispersed in a liquid, surfactants are adsorbed at the interface, changing the interfacial surface tension. These compounds also have a common feature that is the ability to form micelles. Surfactants are characterized by resistance to alkali and hard water.
Solubility in water
Surfactants, because of their hydrophilic-hydrophobic structure, dissolve in many solvents. The solubility in polar compounds results from the presence of a hydrophilic fragment in the molecule. However, the longer and less branched hydrocarbon chain, the lower the solubility in water.
The solubility of surfactants in water can be regulated by modifying their structure. Increasing the solubility is possible by introducing into the molecule a polyoxyethylene moiety or after crossing the Krafft point, i.e. a certain temperature, above which there is a sudden increase in solubility due to the formation of micelles. The solubility of the surfactant in water can be reduced by incorporating propylene oxide molecules into its structure.
Surface tension is a force which acts at the interface. It is a constant and characteristic value for each liquid, strongly dependent on the temperature and the environment with which the liquid is in contact. The surface tension is the result of the unbalance of forces acting on the molecules located on the surface of the liquid and inside it.
The surfactant molecules are adsorbed on the surface of the liquid phase, orientating with the polar head to the inside of the liquid, and the hydrophobic tail towards the air. As a result of such a setting of particles, the surface tension of the liquid decreases. When adding larger amounts of surfactant, its molecules dissipate in the entire liquid volume in a disordered manner until the critical micelle concentration (CMC) is exceeded. Then the molecules begin to organize themselves into spherical forms called micelles.
When the surfactant concentration in the solution increases, its surface tension decreases to a certain level and remains constant irrespective of further concentration of the substance. Non-ionic surfactants reduce surface tension most effectively.
Foaming properties are the ability of surfactants to form foam. Their measure is the volume of foam made from a solution containing a surfactant under certain conditions. This property of surface-active compounds results from the ability to organize micelles and stabilize air bubbles. The surfactant molecules enclose the gas bubble with a thin film at the water-air interface, creating a foam.
Foaming ability of surfactants play an important role in many industrial applications, such as mineral flotation, detergent production and the food industry. In some cases, foaming is undesirable and even harmful. This phenomenon interferes mainly in the processes of the textile industry, industrial washing and cleaning as well as in automatic household washing machines. In order to get rid of or reduce the foamability of surfactants, the anti-foam compounds (e.g., silicone preparations or certain non-ionic surfactants) can be used.
The foaming capacity of each surfactant can be controlled by modifying its structure. The introduction of a polyoxypropylene moiety into the surface active compound molecule reduces foaming while the addition of ethylene oxide increases the surfactant’s foaming capacity.
Wettability is another characteristic feature of surfactants. Due to the ability of their molecules to lower the surface tension between the liquid and the solid and to remove air from the surface of solid bodies, the spreadability of liquid drops on the surface increases significantly. In other words, wettability is the ability to spread the surfactant molecules and their solutions on the surface to which they were applied. The result of this phenomenon is the reduction of the energy barrier between the solution and the wetted surface. This increases the contact surface, which affects the efficiency and speed of the given process (e.g. washing).
Thanks to this property of surfactants, it is possible to quickly wet the fabric with water, which speeds up the washing process. This feature is also used in agrochemistry (e.g. wetting the surface of leaves with spray liquid), in the paint and varnish industry as well as in the construction industry.
Emulsification is the formation of a suspension of two insoluble, immiscible substances, at least one of which is a liquid. As a result of this process, a heterogeneous dispersion system is formed, i.e. a so-called emulsion. If both components are liquids, the emulsion is a suspension of droplets of one phase in the other. Then one of the liquids is a continuous – external phase and the other is a dispersed – inner phase. However, for such a system to be stable, it is necessary to use a surfactant that will surround the drops of one liquid, separating them from the second phase and preventing them from joining larger aggregates. This is due to the appropriate ordering of the surface active compound molecules. They line up with a hydrophilic head towards the polar solvent and a hydrophobic tail towards the non-polar phase. In this way, oil-in-water emulsions are formed, where the continuous phase is polar water with a dispersed non-polar oil phase, or analogously – W / O emulsions, i.e. water in oil.
The ability to create emulsions allows the use of surfactants in many industries. Thanks to this phenomenon, it is possible to manufacture cosmetics, paints, adhesives, varnishes and plastics. In addition, surfactants are used as emulsifiers in the metallurgical, food, mining, fuel, textile, chemical, construction and many other industries.
Detergency is a process of removing dirt. It occurs with the participation of surfactant molecules that surround dirt particles, lining up with nonpolar tails (hydrocarbon chains) towards them. Then they remove the dirt from the surface and surround it, creating a micelle. The emulsion thus created allows the dirt to be easily removed. It is worth mentioning that surfactants show a synergy effect in combination with other surfactants. Synergism is a phenomenon in which the effect of two or more components is greater than the sum of them separately.
What are the types of surfactants?
Surfactants that dissociate in water form anions, cations or when their charge depends on the pH of the environment, are included in the class of ionic surfactants. In contrast, surfactants having non-dissociative moieties are called non-ionic surfactants.
Depending on the construction, and more specifically the charge, which ionic surfactants obtain in aqueous solutions, they are divided into four types.
- Anionic – they have a hydrophilic fragment with a negative charge, and are characterized by cleaning and washing abilities. They occur in liquid and powder detergent formulations. They have foam forming and wetting properties. They act moderately irritating to the skin. They often require the addition of a surfactant to improve the viscosity of the formulation.
- Cationic – they have a “head” with a positive charge and are characterized by conditioning, antistatic and bactericidal properties.
- Amphoteric – they have positive and negative charges in the surface part. Their functions are: forming and stabilizing foam, emulsifying and wetting. They reduce the irritating effect of chemicals on the skin and do not cause irritation on their own. They are compatible with anionic surfactants and characterized by high biodegradability.
- Non-ionic – The hydrophilic fragment does not have ionic charge. They are characterized by emulsifying, wetting and dispersing properties. They have the ability to stabilize foam in hard water and provide synergy with anionic surfactants. They are characterized by high biodegradability and exhibit less irritating effect than anionic surfactants.
Another way to classify surfactants is to divide them according to the application properties – the HLB values. The hydrophilic-lipophilic balance (HLB) according to the calculation method developed by Griffin, determines the percentage of hydrophilic groups in the total mass of surfactant. The scale can take values from 0 to 20.
The lower the HLB value of the surface compound, the better its solubility in oils and other hydrophobic compounds. In contrast, the higher the HLB value, the more hydrophilic the compound is – its solubility in water increases and solubility in oils decreases.
The breakdown into 7 groups according to the possible application of surfactants, depending on the HLB value:
- anti-foaming agents – HLB value: 0-2,
- emulsifiers, water-in-oil (W / O) – HLB value: 3-6,
- wetting agents – HLB value: 7-9,
- emulsifiers, oil-in-water (O / W) – HLB value: 8-15,
- detergents and cleaning agents – HLB value: 12-15,
- foaming agents – HLB value: 14-18,
- solubilizers – HLB value: 12-18.
Using the above information, it is much easier to choose the right ingredients in the formulas for preparations with a specific application.
Where are the surfactants used?
Surfactants act as cleaning, wetting, emulsifying, dispersing, foaming and defoaming agents in many different applications and products. They also improve the application properties, durability and effectiveness of finished products.
Due to the variety of properties, surface-active compounds have been used, among others, in:
- household chemicals as components of detergents and fabric conditioners,
- the chemical industry – for the production of emulsions and plasticizers,
- the cosmetics industry as ingredients of soaps, shampoos, hair conditioners and toothpastes,
- the food industry as stabilizers and emulsifiers,
- the paper and textile industry as components of paints, varnishes, inks and printer inks,
- the oil and mining industry as demulsifiers in the desalination of crude oil and as additives to petroleum products,
- microelectronics for the production of magnetic particles,
- the pharmaceutical industry,
- foam-forming extinguishing agents,
- agrochemical preparations and insecticides as adjuvants.
The most widely used in industry are anionic and non-ionic surfactants. Cationic surfactants are used much less often due to their lower biodegradability. Amphoteric surfactants due to the high cost of production are usually used in specialist applications.
The most popular anionic surfactants are LAS – linear alkyl benzene sulphonates. They are readily used because of the low price and environmental safety. Often used surfactants are also alcohol sulphates and their alkoxylates and sulfonated alphaolefins. Among the non-ionic surfactants, fatty alcohol ethoxylates, alkoxylated alkylphenols and alkyl polyglucosides are used in the largest amounts.
What is the impact of surfactants on the natural environment?
Surfactants have a limited impact on the natural environment. Some of them are easily biodegradable and have no harmful effect on plants, animals and people. They do not contribute to soil or water pollution.
Some groups of surfactants, however, are hazardous to the environment. The most deleterious are cationic surfactants, the toxicity of which is mainly exhibited by their metabolites (such as, for example, nonylphenol), which result from the decomposition of sulfate by bacteria. These substances quickly absorb and interfere with the life cycle of organisms, causing their dysfunctions. Substances that are not biodegradable remain unchanged in the environment. In low concentrations, they usually do not pose a greater risk.
However, it should be borne in mind that some surfactants are also dangerous for the human body. They can irritate the skin, eyes and respiratory system and even cause damage to them. Surfactants may also be harmful if swallowed. Therefore, when working with these compounds, use appropriate personal protective equipment.
What are the forecasts for the surfactants market?
Currently, both in Poland and in the world, the demand for surfactants is very high. According to market research, interest in this group of compounds is growing and will continue to grow in the coming years. The main reason for this trend is the increase in the sale of surfactants, which is the result of increasing consumption. The market for surface-active compounds today belongs to several dozen leading manufacturers, and the success in this industry results mainly from innovations, multifunctional products as well as the identification of market niches and the adaptation of a specialized offer to their individual needs. Therefore, surfactant manufacturers focus on the development of technologies for the production of these substances, and on looking for new, specialized applications.
The surfactants market is divided into two parts. The first are surfactants produced and consumed in large quantities, called mass surfactants. The second group is specialized surfactants whose properties and application are tailored to the specific needs of recipients. Both of these groups are very popular among customers, mainly companies operating in the household chemistry and personal hygiene industry, as well as manufacturers of formulas for industrial applications. The sale takes place directly by the manufacturer or through a network of distributors – surfactant suppliers.
The factors that affect the sale of surfactants are in particular: the demand for products produced on the basis of surfactants, trends in industrial sectors, as well as new technologies. The condition of the Polish and global economy, monetary policy and external financing opportunities also have a great impact. While the prices of raw materials, competition among suppliers of surfactants as well as production costs of products have a direct impact on the sale of surfactants.
The Asia Pacific area is the region where the market for surfactants is the fastest growing in terms of both sales and consumption. Currently, it is the most prospective market for manufacturers of this group of compounds. The potential lies in macroeconomic factors such as high rate of economic growth, unsaturated markets, population growth and increasing living standards. The European market differs from the global market with saturation and competition. The largest recipient in terms of consumption is Germany.
Where to buy surfactants and what is their price?
Manufacturers of surfactants, in order to meet the requirements of customers, are still improving production technologies. They are developing and implementing new groups of surface-active compounds, finding their next applications.
One of the important surfactants suppliers on the market is the PCC Group. The sales market in Poland is 57%, and the remaining 43% of revenues is generated by the Group from operations abroad. The largest customer is the Western European market, mainly Germany, France, Italy and the Netherlands, which accounts for 17% of the revenue value. The regions of Africa, the Middle East and Central and Eastern Europe generate a total of 30% of the value of foreign sales. The data presented concern the sale of surfactants in 2017.
The PCC Group builds its position both as a supplier of surfactants and also as a trading partner with ready-made industrial formulations. The company proposes innovative solutions that reach the most demanding recipients. By focusing its activities on the individual needs of customers looking for universal ingredients of the formulation, the Group is constantly expanding its product portfolio.
The PCC Group provides surfactants with the highest quality guarantee. The PCC Group specialists will prepare a competitive offer, provide professional assistance in the selection of the product, present the best variant for the given application, as well as ensure reliable and safe transport to the required destination.
The PCC Group’s offer includes surfactants dedicated to various applications. For this reason, prices are individually agreed with each customer. In order to purchase or familiarize yourself with the available products, please visit the PCC Group. By clicking the link below, you can receive information on where to buy surfactants.
Simply fill out the short form available on the website, call or send an e-mail, and company experts will contact you and prepare an individual offer. The PCC Group is a company where you can buy surfactants in both wholesale and retail quantities. In addition, PCC Group specialists will present delivery conditions, availability and price, as well as advise on the potential applications of selected products.