Difference Between Anionic Cationic and Nonionic Surfactants

The term surfactant refers to surfactants. This means that surfactants can reduce the surface tension between two substances. Surfactants are substances that reduce the surface tension of liquids, making them useful in various applications such as cleaning, emulsification, and foaming. Anionic, cationic, and nonionic surfactants are the three main types of surfactants based on their ionic charge. Anionic surfactants have a negative charge, cationic surfactants have a positive charge, and nonionic surfactants have no charge. These different types of surfactants have distinct properties, behaviors, and applications, which make them suitable for specific uses. For example, anionic surfactants are commonly used in household cleaning products, cationic surfactants are used in hair conditioners, and nonionic surfactants are used in emulsions and food products. 

1. Anionic Surfactants

Anionic surfactants are surfactants that have a negative charge. They are characterized by a polar head group and a hydrophobic tail. Some common examples of anionic surfactants include sodium lauryl sulfate (SLS), sodium dodecylbenzene sulfonate (SDBS), and sodium alkyl ether sulfate (SAES). Anionic surfactants are highly soluble in water and are often used in household cleaning products such as detergents, soaps, and shampoos due to their cleaning properties. They are effective at removing grease and oil and have good foaming properties.

Anionic surfactants are commonly used in cleaning products, such as laundry detergents, because of their ability to emulsify oil and grease.

Some common types of anionic surfactants include:

• Sodium alkyl sulfates
• Sodium alkylbenzene sulfonates
• Sodium alkyl ether sulfates
• Sodium lauryl sulfoacetate
• Sodium dodecylbenzenesulfonate (SDS)

Advantages of Anionic Surfactants

1. Good cleansing properties, making them effective for cleaning
2. Inexpensive to produce
3. Good stability and ability to form stable emulsions

Limitations of Anionic Surfactants

1. Can be harsh on skin and hair due to their strong cleansing properties
2. May cause irritation and sensitization in some individuals
3. Can cause damage to natural fibers and dyes

2. Cationic Surfactants

Cationic surfactants are surfactants that have a positive charge. They are characterized by a polar head group with a positive charge and a hydrophobic tail. Some common examples of cationic surfactants include cetyltrimethylammonium bromide (CTAB), benzalkonium chloride (BAC), and dodecylbenzene sulfonic acid. Most of these surfactants can destroy the cell membranes of bacteria and viruses, so they are useful as antibacterial agents, antifungal agents, etc. The most common functional group found in these molecules is the ammonium ion

Cationic surfactants are used in fabric softeners, hair conditioners, and in certain sanitizers and disinfectants due to their positive charge, which makes them attracted to negatively charged surfaces such as hair and skin.

Some common types of cationic surfactants include:

• Quaternary ammonium compounds
• Imidazolinium derivatives
• Ammonium carboxylates
• Alkyl trimethylammonium salts
• Alkylbenzyldimethylammonium salts

Advantages of Cationic Surfactants:

1. Good conditioning properties, making them useful in hair care products
2. Effective in controlling bacteria and other microorganisms

Limitations of Cationic Surfactants:

1. Can cause skin and eye irritation
2. Can interact with other ingredients in a formulation, affecting its stability
3. May produce a negative charge in water, making it difficult to disperse other ingredients

3. Nonionic Surfactants

Nonionic surfactants are a type of surface-active agents that do not carry an electrical charge. They are made by adding a hydrophobic (water-repellent) group to a hydrophilic (water-soluble) group. Unlike ionic surfactants, nonionic surfactants do not react with ions in solution and do not ionize in water. In addition, they have covalently bound oxygen-containing hydrophilic groups. These hydrophilic groups associate with the hydrophobic backbone when detergent is added to the sample. The oxygen atoms in these compounds can affect the hydrogen bonding of surfactant molecules.

Nonionic Surfactants are used in Personal care products, such as creams, lotions, and makeup, in Food processing as emulsifiers and dispersants, in Pesticides and herbicides, Industrial and household cleaning products, and in 

Pharmaceuticals and drug delivery systems.

Some common types of nonionic surfactants include:

• Polyoxyethylene alkyl ethers
• Polyoxyethylene alkylphenol ethers
• Fatty alcohol polyglycol ethers
• Glyceryl esters
• Sorbitan esters

Advantages of Nonionic Surfactants

1. Mild and gentle on skin and hair
2. Good emulsifying properties, making them useful in cosmetic and food applications
3. Typically stable and compatible with a wide range of ingredients

Limitations of Nonionic Surfactants

1. May be less effective in removing grease and oil compared to anionic and cationic surfactants
2. More expensive to produce compared to anionic surfactants
3. May not be effective in controlling bacteria and other microorganisms like cationic surfactants.

Difference Between Anionic, Cationic Surfactants, and Nonionic Surfactants

There are three main types of surfactants: anionic surfactants, cationic surfactants, and nonionic surfactants. The main difference between anionic cationic and nonionic surfactants is that anionic surfactants contain negatively charged functional groups while cationic surfactants have positively charged functional groups. contain, whereas nonionic surfactants have no net charge. 

Examples of anionic surfactants include compounds containing sulfonates, phosphates, sulfates, and carboxylates. Cationic surfactants primarily contain ammonium cations. 

1. Anionic Surfactants

• Carry a negative charge
• Typically have a hydrophobic (water-repellent) tail and a hydrophilic (water-soluble) head
• Often used in cleaning products, such as laundry detergents and dishwashing liquids
• Can cause skin irritation
• React with hard water to form calcium and magnesium salts, which can reduce their effectiveness
• Functional groups are Sulfonate, phosphate, sulfate, and carboxylates.

2. Cationic Surfactants

• Carry a positive charge
• Typically have a hydrophobic tail and a hydrophilic head
• Used in fabric softeners, conditioners, and sanitizers
• Can cause skin irritation
• Can interact with anionic surfactants to form complexes that can be difficult to remove from fabrics
• Their functional group is Ammonium cation.

3. Nonionic Surfactants

• do not carry an electrical charge
• typically have a hydrophobic tail and a hydrophilic head
• used in a wide range of products, including household cleaning products, personal care products, and emulsifiers
• generally considered to be less irritating to the skin than anionic or cationic surfactants
• less likely to react with hard water, making them more effective in areas with high mineral content.
• They have no charged functional groups

Property

Anionic Surfactants

Cationic Surfactants

Nonionic Surfactants

ChargeNegativePositiveNeutralFunctionalityGood cleaning and degreasingGood conditioning and antistaticGood emulsification and foam stabilizationExamplesSodium lauryl sulfate (SLS), Sodium dodecylbenzenesulfonate (SDBS)Quaternary ammonium compounds (Quats), Cetyltrimethylammonium chloride (CTAC)Ethoxylated alcohols, Polyethylene glycol (PEG) estersApplicationsDetergents, shampoos, toothpaste Conditioners, sanitizers, fabric softenersPersonal care, household cleaning, agriculture

Conclusion

In conclusion, anionic, cationic, and nonionic surfactants are all types of surfactants that differ in their charge properties. Anionic surfactants have a negative charge and are commonly used for cleaning applications due to their strong cleansing properties. Cationic surfactants have a positive charge and are used in hair care products for their conditioning properties and ability to control bacteria. Nonionic surfactants have no charge and are known for their mildness and compatibility with a wide range of ingredients. Each type of surfactant has its own advantages and limitations, making them suitable for different applications based on their specific properties.

Last Updated :

24 Feb, 2023

Like Article

Save Article

Share your thoughts in the comments

Please

Login

to comment...