By TRUNNANO | 13 March 2024 | 0 Comments
Four types of surfactants and their differences and applications
What is a surfactant?
Surfactants are substances that can significantly reduce surface tension (or interfacial tension). They have fixed hydrophilic and lipophilic groups that can be oriented on the surface of a solution, resulting in a significant decrease in surface tension. Depending on their molecular composition and properties, surfactants can be divided into four main categories: anionic, cationic, amphoteric, and nonionic.
Overview of the four types of surfactants
Anionic surfactants
Anionic surfactants have the longest history of development, the largest production volume, and the largest variety of surfactants. They ionize when dissolved in water, generating negatively charged hydrophobic and hydrophilic groups. The hydrophilic groups of anionic surfactants are generally carboxylates, sulfonates, sulfate salts, phosphate salts, and so on.
Cationic surfactants
Cationic surfactants are usually nitrogen-containing organic amine derivatives. The nitrogen atom in their molecule contains a lone pair of electrons, so it can be combined with the hydrogen in the acid molecule by hydrogen bonding, making the amino group positively charged. Therefore, they have good surface activity in acidic mediums but easily lose surface activity in alkaline mediums.
Amphoteric surfactants
Amphoteric surfactants have both positive and negatively charged groups in the molecule and can exhibit the properties of cationic or anionic surfactants in different pH media.
Nonionic surfactants
Nonionic surfactants do not dissociate in water. Their hydrophilic groups are polyols such as glycerol and polyethylene glycol, and their lipophilic groups are long-chain fatty acids or long-chain fatty alcohols, as well as alkyl or aryl groups. 
Differences between the four types of surfactants
Charge properties
Anionic surfactants are negatively charged, cationic surfactants are positively charged, amphoteric surfactants can be positively or negatively charged in different environments, and nonionic surfactants are uncharged. This difference in nature directly affects their interaction with other charged particles in solution, thus determining their application characteristics.
Hydrophilic Lipophilic Balance (HLB) Value
The HLB value reflects the balance between the hydrophilicity and lipophilicity of a surfactant. Different types of surfactants have different HLB values, which determine their applicability in different systems. For example, anionic and nonionic surfactants usually have higher HLB values and are suitable for preparing oil-in-water emulsions, while cationic types are suitable for water-in-oil emulsions.
Stability
Cationic surfactants tend to lose surface activity in alkaline media, while anionic and nonionic types are relatively more stable. Amphoteric surfactants can maintain better stability in a wide pH range due to their special charge properties.
Toxicity
Generally speaking, cationic surfactants are more toxic, while anionic and nonionic types are relatively less toxic. Therefore, when selecting surfactants, their usage scenarios and safety requirements need to be considered.
Application of the four types of surfactants
Application of anionic surfactants
Anionic surfactants are widely used in detergents, cosmetics, textiles, pharmaceuticals, and other fields due to their good detergency, emulsification, dispersion, and wetting properties. For example, in detergents, anionic surfactants can effectively remove grease and dirt; in cosmetics, they can be used as emulsifiers and thickeners; in the textile industry, they can be used as wetting agents and softeners.
Application of cationic surfactants
Cationic surfactants have excellent bactericidal, antistatic, and softening properties, so they are commonly used in the preparation of bactericides, antistatic agents, softeners, and hair conditioners. In the medical field, cationic surfactants are also often used as disinfectants to kill bacteria and viruses.
Application of Amphoteric Surfactants
Amphoteric surfactants are widely used in personal care products such as shampoos, body washes, and skin care products due to their unique charge properties and good biocompatibility. In addition, they can be used to prepare materials with special functions, such as antimicrobial materials and antistatic materials.
Application of nonionic surfactants
Due to their mild surface activity and good stability, nonionic surfactants are commonly used in the preparation of emulsions, microcapsules, solubilizers, and other preparations. In the pharmaceutical field, they can be used to prepare injectable emulsions, liposomes, and other drug delivery systems; in the food industry, they can be used as emulsifiers, stabilizers, and wetting agents.
To summarize, the four surfactants have their characteristics and have a wide range of applications in different fields. In practical application, it is necessary to select the appropriate surfactant according to the specific needs in order to achieve the best use effect. At the same time, it is also necessary to pay attention to the safety and environmental protection of surfactants to ensure that they are harmless to human beings and the environment in the process of production and use.
Different surfactant supplier in China
Luoyang Trunnano Tech Co., Ltd (TRUNNANO) is professional in cladding of metal solutions for 10 years+, which is a professional company with supply and marketing integration.
We provides different kinds of surfactants, such as anionic surfactants, sodium lauryl sulfate, sodium laureth sulfate, sodium lauroyl sarcosinate,etc.
The company has a professional technical department and Quality Supervision Department, a well-equipped laboratory, and equipped with advanced testing equipment and after-sales customer service center. Send us an email to [email protected] or click on the needed products to send an inquiry.
Surfactants are substances that can significantly reduce surface tension (or interfacial tension). They have fixed hydrophilic and lipophilic groups that can be oriented on the surface of a solution, resulting in a significant decrease in surface tension. Depending on their molecular composition and properties, surfactants can be divided into four main categories: anionic, cationic, amphoteric, and nonionic.
Overview of the four types of surfactants
Anionic surfactants
Anionic surfactants have the longest history of development, the largest production volume, and the largest variety of surfactants. They ionize when dissolved in water, generating negatively charged hydrophobic and hydrophilic groups. The hydrophilic groups of anionic surfactants are generally carboxylates, sulfonates, sulfate salts, phosphate salts, and so on.
Cationic surfactants
Cationic surfactants are usually nitrogen-containing organic amine derivatives. The nitrogen atom in their molecule contains a lone pair of electrons, so it can be combined with the hydrogen in the acid molecule by hydrogen bonding, making the amino group positively charged. Therefore, they have good surface activity in acidic mediums but easily lose surface activity in alkaline mediums.
Amphoteric surfactants
Amphoteric surfactants have both positive and negatively charged groups in the molecule and can exhibit the properties of cationic or anionic surfactants in different pH media.
Nonionic surfactants
Nonionic surfactants do not dissociate in water. Their hydrophilic groups are polyols such as glycerol and polyethylene glycol, and their lipophilic groups are long-chain fatty acids or long-chain fatty alcohols, as well as alkyl or aryl groups.
Charge properties
Anionic surfactants are negatively charged, cationic surfactants are positively charged, amphoteric surfactants can be positively or negatively charged in different environments, and nonionic surfactants are uncharged. This difference in nature directly affects their interaction with other charged particles in solution, thus determining their application characteristics.
Hydrophilic Lipophilic Balance (HLB) Value
The HLB value reflects the balance between the hydrophilicity and lipophilicity of a surfactant. Different types of surfactants have different HLB values, which determine their applicability in different systems. For example, anionic and nonionic surfactants usually have higher HLB values and are suitable for preparing oil-in-water emulsions, while cationic types are suitable for water-in-oil emulsions.
Stability
Cationic surfactants tend to lose surface activity in alkaline media, while anionic and nonionic types are relatively more stable. Amphoteric surfactants can maintain better stability in a wide pH range due to their special charge properties.
Toxicity
Generally speaking, cationic surfactants are more toxic, while anionic and nonionic types are relatively less toxic. Therefore, when selecting surfactants, their usage scenarios and safety requirements need to be considered.
Application of the four types of surfactants
Application of anionic surfactants
Anionic surfactants are widely used in detergents, cosmetics, textiles, pharmaceuticals, and other fields due to their good detergency, emulsification, dispersion, and wetting properties. For example, in detergents, anionic surfactants can effectively remove grease and dirt; in cosmetics, they can be used as emulsifiers and thickeners; in the textile industry, they can be used as wetting agents and softeners.
Application of cationic surfactants
Cationic surfactants have excellent bactericidal, antistatic, and softening properties, so they are commonly used in the preparation of bactericides, antistatic agents, softeners, and hair conditioners. In the medical field, cationic surfactants are also often used as disinfectants to kill bacteria and viruses.
Application of Amphoteric Surfactants
Amphoteric surfactants are widely used in personal care products such as shampoos, body washes, and skin care products due to their unique charge properties and good biocompatibility. In addition, they can be used to prepare materials with special functions, such as antimicrobial materials and antistatic materials.
Application of nonionic surfactants
Due to their mild surface activity and good stability, nonionic surfactants are commonly used in the preparation of emulsions, microcapsules, solubilizers, and other preparations. In the pharmaceutical field, they can be used to prepare injectable emulsions, liposomes, and other drug delivery systems; in the food industry, they can be used as emulsifiers, stabilizers, and wetting agents.
To summarize, the four surfactants have their characteristics and have a wide range of applications in different fields. In practical application, it is necessary to select the appropriate surfactant according to the specific needs in order to achieve the best use effect. At the same time, it is also necessary to pay attention to the safety and environmental protection of surfactants to ensure that they are harmless to human beings and the environment in the process of production and use.
Different surfactant supplier in China
Luoyang Trunnano Tech Co., Ltd (TRUNNANO) is professional in cladding of metal solutions for 10 years+, which is a professional company with supply and marketing integration.
We provides different kinds of surfactants, such as anionic surfactants, sodium lauryl sulfate, sodium laureth sulfate, sodium lauroyl sarcosinate,etc.
The company has a professional technical department and Quality Supervision Department, a well-equipped laboratory, and equipped with advanced testing equipment and after-sales customer service center. Send us an email to [email protected] or click on the needed products to send an inquiry.
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