Understanding Anionic Surfactants in Household and Personal-Care Formulations from a Structural Perspective: Structural and Performance Differences among Representative Raw Materials such as LAS, AES, K12, AOS, MES, and FMES

1 Structure Determines the Performance Differences of Anionic Surfactants

In household and personal-care raw materials, anionic surfactants are among the most important cleansing surfactants. They are typically composed of a hydrophobic hydrocarbon chain and a negatively charged hydrophilic head group. In aqueous solution, they can adsorb at gas/liquid, oil/water, and solid/liquid interfaces, reduce interfacial tension, and form micelles after reaching the critical micelle concentration, thereby enabling wetting, emulsification, dispersion, and detergency.

To evaluate an anionic surfactant, it is necessary to return to three structural questions:

Evaluation Dimension	Main Effects
Hydrophilic head group	Water solubility, hard-water tolerance, pH compatibility, irritation tendency
Hydrophobic chain	Degreasing ability, foam, critical micelle concentration, low-temperature solubility, raw-material cost
Linking group	Mildness, compatibility, liquid stability, alkali resistance, formulation adaptability

The differences among LAS, AES, K12, AOS, MES, and FMES are external manifestations of molecular structural differences during the cleaning process. The following sections compare representative anionic surfactants from the perspective of structural differences, with a focus on how hydrophilic head groups, hydrophobic chains, and linking groups affect cleaning power, foam, mildness, hard-water tolerance, cost sources, and raw-material positioning.

2 Mechanism of Action of Anionic Surfactants

2.1 Cleaning Is Not Simply “Dissolving Dirt,” but Changing the Interfacial State

Most oily soils, sebum, particulate soils, and waxy soils do not simply dissolve in water. The role of anionic surfactants is to use their amphiphilic structure to alter the interfacial state among water, soils, and the surface being cleaned. The basic processes include:

Process	Description
Wetting	Reduces the surface tension of water, allowing water to spread more easily over fabrics, skin, tableware, or hard surfaces
Interfacial adsorption	The hydrophobic chain approaches oily soils or hydrophobic surfaces, while the hydrophilic head group faces the aqueous phase, reducing oil/water or solid/liquid interfacial tension
Detachment	Under the combined effects of mechanical force, changes in interfacial tension, and electrostatic repulsion, soils are detached from the surface
Emulsification and dispersion	Disperses oily soils or particulate soils into the aqueous phase and reduces re-aggregation
Micellar solubilization	The hydrophobic core of micelles incorporates oily components, allowing them to be carried away with the aqueous phase
Anti-redeposition	The negative charge introduced by anionic head groups helps reduce the likelihood of soils re-adhering to the surface

2.2 How Structure Affects Performance

The performance of anionic surfactants is mainly determined by the following structural factors.

① The hydrophilic head group determines ionic behavior.

Carboxylates, sulfate esters, sulfonates, isethionates, and amino acid salts differ in hydration ability, sensitivity to metal ions, and pH compatibility. Fatty acid soaps are carboxylates and are sensitive to calcium and magnesium ions. LAS, AOS, MES, FMES, and SAS belong to sulfonate systems; sulfonate head groups generally have good chemical stability, while the overall stability of MES and FMES still needs to be evaluated in relation to ester groups, ethoxylated segments, pH, temperature, and the specific commercial composition. K12 and AES belong to sulfate ester/ether sulfate systems and show prominent foaming and detergency performance.

② The hydrophobic chain determines degreasing and micellization ability.

C12–C14 chains generally provide good foaming and cleaning performance. As chain length increases, hydrophobic interaction becomes stronger, but water solubility and low-temperature solubility may decrease. The source of the hydrophobic chain also affects cost fluctuations. For example, the fatty alcohol chain of AES is closely related to the supply of C12–C14 fatty alcohols, which are often associated with lauric oil raw materials such as palm kernel oil and coconut oil.

③ The linking group determines differences in use.

Compared with K12, AES contains an additional polyoxyethylene chain, so it has better hydration ability, solubility, and formulation adaptability. MES contains both an ester group and a sulfonate structure, giving it an oleochemical origin and good detergency, but hydrolysis, low-temperature solubility, and stability need to be considered in liquid systems. SCI and amino acid-based anionics are often used in mild cleansing systems because of their different head-group structures.

3 Fatty Acid Soaps: Carboxylate Structure and Hard-Water Sensitivity

3.1 Fatty Acid Soap Is the Starting Point of Traditional Anionic Surfactants

The typical structure of fatty acid soap is:

RCOO⁻Na⁺ or RCOO⁻K⁺

where R is a long-chain fatty hydrocarbon group, and RCOO⁻ is the carboxylate head group. Fatty acid soaps are usually produced by saponification of natural oils and fats, or by neutralization of fatty acids with alkali. They are characterized by strong cleaning power, direct foaming, a fresh rinsing feel, and a simple structure, making them one of the representative anionic cleansing raw materials in traditional cleaning systems.

3.2 The Shortcomings of Fatty Acid Soap Come from the Carboxylate Head Group

The biggest problem with fatty acid soap is its sensitivity to hard water. Ca²⁺ and Mg²⁺ in hard water can react with fatty acid anions to form poorly soluble calcium soaps and magnesium soaps, resulting in reduced foam, lower cleaning efficiency, and the formation of soap scum. The head-group structure directly affects hard-water tolerance. The development of modern synthetic anionic surfactants has, to a large extent, been driven by the need to address the shortcomings of soap-based systems in hard water, pH compatibility, and system stability.

4 Sulfate Ester Systems: Structural Differences between K12 and AES

4.1 K12: A Typical Alkyl Sulfate with Prominent Foaming and Degreasing Ability

K12 usually refers to sodium lauryl sulfate, also known as SLS, or sodium dodecyl sulfate, also known as SDS. Its typical structure is:

C12 alkyl chain + sulfate ester head group

K12 can be represented as:

C₁₂H₂₅-O-SO₃⁻Na⁺

K12 has a simple molecular structure, with no obvious buffering structure between the hydrophobic chain and the strongly hydrophilic head group. It has the following characteristics:

Item	Performance
Foaming	Rapid foaming and high foam volume
Degreasing	Strong oil-removal ability and a clear cleansing feel
Solubility	Good under appropriate temperature and concentration conditions
Mildness	Relatively obvious defatting feel and irritation
Suitable applications	Strong foaming, strong cleansing, powder systems, or certain cleansing systems

The advantages of K12 come from its direct and efficient amphiphilic structure; its limitations also arise from this structure. Because it lacks flexible hydrated segments such as ethoxylated chains, it interacts more strongly with skin proteins and the lipid layer, and its defatting feel and irritation are generally higher than those of AES.

4.2 AES: The Addition of an EO Chain Significantly Changes Performance

AES, or Alcohol Ether Sulfate, is a fatty alcohol polyoxyethylene ether sulfate. A common commercial product is SLES, or Sodium Laureth Sulfate. Its typical structure can be represented as:

R-O-(CH₂CH₂O)n-O-SO₃⁻Na⁺

Here, R is usually a C12–C14 fatty alcohol chain, and n is the average degree of ethoxylation. AES is an ether sulfate-type anionic surfactant, not a sulfonate.

Compared with K12, the key structural difference of AES is the introduction of a polyoxyethylene chain formed from EO, or ethylene oxide. This structural change leads to three main effects:

Structural Change	Performance Result
Addition of EO chain	Enhanced hydration ability and improved solubility
Increased hydrophilic-region volume	Reduced direct interaction with skin and proteins; mildness is generally better than K12
Increased molecular flexibility	More suitable for liquid systems, with better foam, viscosity, and formulation compatibility

4.3 Relationship between AES Cost and the Fatty Alcohol Raw-Material Chain

The production route of AES usually includes:

Fatty alcohol → ethoxylation → sulfation → neutralization → AES

Fatty alcohol is the key raw material. C12–C14 fatty alcohols are often derived from lauric oil routes such as palm kernel oil and coconut oil. Therefore, when the supply of palm kernel oil, coconut oil, or C12–C14 fatty alcohols becomes tight or prices rise, AES costs are easily affected. At the same time, ethylene oxide, sulfation costs, energy, transportation, inventory cycles, and supply-demand conditions also influence AES pricing.

5 Sulfonate Systems: Structural Differences among LAS, AOS, and MES

LAS, AOS, and MES are all sulfonate-type anionic surfactants, but their hydrophobic structures and raw-material routes differ, resulting in clearly different performance and positioning.

5.1 LAS: A Basic Raw Material with High Detergency and Cost-Effectiveness

LAS, or Linear Alkylbenzene Sulfonate, is a linear alkylbenzene sulfonate. In actual production, LABSA, or Linear Alkylbenzene Sulfonic Acid, is commonly used as an acid-form raw material and is converted into LAS salts after neutralization with alkali.

Its structural features are:

Linear alkyl chain + benzene ring + sulfonate head group

The performance of LAS comes from three structural factors:

Structural Factor	Function
Linear alkyl chain	Provides hydrophobic interaction and oil-removal ability
Benzene ring	Enhances the rigidity of the hydrophobic backbone and interaction with oily soils
Sulfonate head group	Provides good water solubility and relatively good chemical stability

The core value of LAS lies in its strong detergency, low cost, and mature supply. Its limitations include moderate mildness and the need for builders, auxiliaries, or formulation combinations to improve performance in hard water. Acid-form LABSA must be neutralized and its pH controlled before being used in formulations. LAS is suitable as a basic detergency backbone, but it is not suitable for independently carrying requirements related to mildness, skin feel, or special functions.

5.2 AOS: A Representative Material with High Foam, Hard-Water Tolerance, and Stability

AOS, or Alpha Olefin Sulfonate, is an alpha-olefin sulfonate. AOS is usually a mixture of components such as alkenyl sulfonates and hydroxyalkyl sulfonates.

Its structural features can be summarized as:

Long-chain alkenyl/hydroxyalkyl structure + sulfonate head group

The main characteristics of AOS include:

Item	Performance
Foam	Rapid foaming and rich foam
Hard-water tolerance	Good
Chemical stability	The sulfonate structure provides good stability
Detergency	Provides good cleaning action against common oily soils and particulate soils
Compatibility	Can be combined with LAS, AES, K12, and other surfactants

The value of AOS lies in its ability to achieve a good balance among foam, hard-water tolerance, and stability. AOS is suitable as an important anionic raw material in systems requiring high foam and good hard-water tolerance. AOS is still a relatively strong cleansing anionic surfactant. If used in skin or scalp cleansing systems, it usually still requires formulation with other ingredients to reduce irritation and improve skin feel.

5.3 MES: Oleochemical-Based and Highly Detergent, but Technically Demanding in Liquid Systems

MES, or Methyl Ester Sulfonate, is a fatty acid methyl ester sulfonate, also known as an alpha-sulfo fatty acid methyl ester salt. It is typically produced from natural oils and fats through transesterification to obtain fatty acid methyl esters, followed by sulfonation and neutralization.

Its structural features are:

Fatty chain + ester group + sulfonate head group

The characteristics of MES come from this structural combination:

Structural Factor	Performance Result
Fatty chain	Provides oil-removal and micellization ability
Ester group	Gives an oleochemical-origin feature and also introduces hydrolysis sensitivity
Sulfonate head group	Provides water solubility, hard-water tolerance, and cleaning ability

The main advantages of MES are good detergency, relatively good hard-water tolerance, good biodegradability, and an oleochemical origin. However, when MES is used in liquid systems, dissolution stability must be given particular attention. Due to factors such as chain-length distribution, Krafft point, low-temperature solubility, ester hydrolysis, and processing stability in high-active-matter states, MES cannot simply replace LAS or AES at the same ratio. In actual use, three issues should be carefully confirmed: whether precipitation or turbidity occurs during low-temperature storage, whether hydrolysis is likely at the target pH, and whether the system remains homogeneous and stable after formulation.

6 FMES: Low-Foam, Alkali-Resistant, and Dispersing Cleaning Applications

6.1 Structural Features of FMES

FMES, or Fatty Methyl Ester Ethoxylate Sulfonate, is a fatty acid methyl ester ethoxylate sulfonate. The specific structure, active-matter content, inorganic salt content, and component distribution may vary among different products.

Its structure can be summarized as:

Fatty chain + ester/ethoxylated segment + sulfonate group

Compared with common cleansing-type anionic surfactants such as LAS, AES, AOS, and MES, FMES is usually positioned as a functional anionic raw material. It is mainly used in low-foam, alkali-resistant, emulsifying and dispersing, oil-removing, wax-removing, and heavy-duty cleaning applications. Its characteristics are concentrated in dispersion, emulsification, and alkali resistance under specific cleaning conditions.

6.2 The Performance Focus of FMES Is Not High Foam, but Functional Cleaning

FMES products are usually positioned for the following applications:

Performance Direction	Functional Significance
Low foam	Suitable for spray cleaning, circulating cleaning, machine cleaning, and other systems where large amounts of foam are not desired
Alkali resistance	Suitable for high-alkali cleaning systems
Emulsification and dispersion	Helps handle oily soils, waxy soils, and composite soils
Oil and wax removal	Suitable for heavy-duty oily soils or professional cleaning applications
Electrolyte compatibility	Offers application value in relatively complex inorganic salt systems

7 SCI and Amino Acid-Based Anionic Surfactants: Structural Logic of Mild Cleansing

The mildness of anionic surfactants is not only related to the strength of cleansing power, but also to head-group structure, hydration ability, molecular size, use concentration, pH, formulation system, and contact time.

7.1 SCI: Fatty Acyl Isethionate and Mild Cleansing Characteristics

SCI, or Sodium Cocoyl Isethionate, is sodium cocoyl isethionate and belongs to fatty acyl isethionate-type anionic surfactants. Its structure can be summarized as:

Coconut fatty acid hydrophobic chain + ester bond + sodium isethionate hydrophilic head group

The coconut fatty acid chain provides interfacial adsorption, foaming, and cleansing effects. The isethionate head group provides water solubility and anionic character. The ester bond connects the fatty chain with the hydrophilic head group, distinguishing SCI from sulfate ester-type anionic surfactants such as K12 and AES. SCI is commonly used in mild cleansing systems and is characterized by fine foam, a softer skin feel after cleansing, and relatively good hard-water tolerance. Its mildness is related to molecular structure, use concentration, pH, formulation system, and contact time.

7.2 Amino Acid-Based Anionic Surfactants: Acyl Amino Acid Salt Structure and Mild Cleansing Characteristics

Amino acid-based anionic surfactants are usually composed of a fatty acyl hydrophobic chain and an amino acid or amino acid-like hydrophilic group. Their structural characteristics are as follows: the fatty acyl group provides interfacial adsorption and cleansing action, while the amino acid or amino acid-like head group provides water solubility, ionic character, and good hydration ability. Therefore, they are often used in formulation research for mild cleansing, mildly acidic systems, and products with higher skin-feel requirements. Common examples include:

Category	Representative
Sarcosinates	Sodium Lauroyl Sarcosinate
Glutamates	Sodium Cocoyl Glutamate
Glycinates	Potassium Cocoyl Glycinate
Taurates	Sodium Methyl Cocoyl Taurate

The core advantages of amino acid-based anionic surfactants are good mildness, skin feel, and compatibility with mildly acidic to neutral systems. However, amino acid-based anionic surfactants also have limitations, such as higher cost, foam structure and thickening behavior that depend on formulation combinations, and strong detergency that is not necessarily superior to AES or LAS.

8 SAS: Structure and Performance Characteristics of Secondary Alkane Sulfonates

SAS, or Secondary Alkane Sulfonate, is a secondary alkane sulfonate. Its structural features are:

Aliphatic alkyl chain + sulfonate group on an internal secondary carbon of the chain

SAS belongs to aliphatic sulfonates. Unlike the alkylbenzene sulfonate structure of LAS, SAS contains no aromatic ring. Unlike the mixed alkenyl sulfonate/hydroxyalkyl sulfonate structure of AOS, the sulfonate group in SAS is mainly located on an internal secondary carbon of the alkyl chain.

SAS has wetting, detergency, foaming, and hard-water tolerance characteristics. Its aliphatic alkyl chain provides hydrophobic interaction and interfacial adsorption ability, while the sulfonate group provides water solubility and anionic character. Because it contains no aromatic ring, SAS differs from LAS in hydrophobic backbone rigidity, interfacial adsorption mode, and raw-material structural origin. Because the sulfonate group is located inside the alkyl chain, SAS also differs from AOS and MES in molecular configuration and cleaning performance.

Product	Sulfonate Structural Feature	Main Structural Difference
LAS	Alkylbenzene sulfonate	Contains an aromatic ring; the hydrophobic backbone has aromatic-ring characteristics
AOS	Mixture of alkenyl sulfonates/hydroxyalkyl sulfonates	Contains alkenyl or hydroxyalkyl structures in the molecule
MES	Alpha-sulfo fatty acid methyl ester salt	Contains an ester group and has the structural features of an oleochemical fatty acid methyl ester
SAS	Secondary alkane sulfonate	Contains no aromatic ring; the sulfonate group is located on an internal secondary carbon of the aliphatic alkyl chain

Although LAS, AOS, MES, and SAS all belong to sulfonate systems, their differences mainly arise from the hydrophobic backbone, the position of the sulfonate group, whether an aromatic ring is present, and whether an ester group is present. These structural differences affect wetting, foam, detergency, solubility, and hard-water tolerance.

9 Comparison of the Structures and Performance of Representative Products

Product	Full Name	Structural Type	Core Advantages	Main Limitations	Raw-Material Positioning
Fatty Acid Soap	Fatty Acid Soap	Fatty acid carboxylate	Strong cleansing feel, fresh rinse-off feel, traditional source	Sensitive to hard water, prone to soap scum formation, alkaline pH	Traditional anionic reference material
LAS	Linear Alkylbenzene Sulfonate	Aromatic sulfonate	Strong detergency, low cost, mature supply	Moderate mildness; requires builders or auxiliaries to improve hard-water performance	Basic detergency backbone
K12/SLS	Sodium Lauryl Sulfate	Alkyl sulfate ester	Rapid foaming, strong degreasing	Relatively obvious irritation and defatting feel	Strong-foaming, strong-cleansing raw material
AES/SLES	Sodium Laureth Sulfate	Alkyl ether sulfate	Balanced foam, solubility, mildness, and formulation compatibility	Cost is affected by fatty alcohols and ethylene oxide	Basic raw material for liquid cleansing systems
AOS	Alpha Olefin Sulfonate	Aliphatic sulfonate	High foam, hard-water tolerance, good stability	Mildness still requires improvement through formulation	Foam and hard-water-tolerance booster
MES	Methyl Ester Sulfonate	Ester-containing sulfonate	Oleochemical-based, high detergency, hard-water friendly	Liquid stability, low-temperature solubility, and hydrolysis require attention	Oleochemical-based high-detergency raw material
FMES	Fatty Methyl Ester Ethoxylate Sulfonate	Functional anionic surfactant containing a sulfonate structure	Low foam, alkali resistance, emulsification and dispersion, oil and wax removal	Product structures vary significantly among manufacturers and require evaluation through testing	Functional raw material for professional cleaning
SCI	Sodium Cocoyl Isethionate	Fatty acyl isethionate	Fine foam, good skin feel, suitable for mild cleansing systems	Relatively high cost; processing and dissolution conditions need to be controlled	Representative mild anionic surfactant
Amino Acid-Based Anionic Surfactants	Amino Acid-based Anionic Surfactants	Acyl amino acid salts	Mild, good skin feel, good compatibility with mildly acidic systems	Relatively high cost; foam and thickening depend on formulation combinations	Mild cleansing raw materials
SAS	Secondary Alkane Sulfonate	Aliphatic sulfonate	Balanced wetting, detergency, and hard-water tolerance	Performance is affected by carbon-chain distribution, active-matter content, and system conditions	Comprehensive aliphatic sulfonate cleansing raw material

10 Determining Raw-Material Suitability Based on Structural Features

10.1 Evaluation by Hydrophilic Head Group

Head-Group Type	Representative Products	Main Characteristics
Carboxylate	Fatty acid soap	Strong cleansing feel, but sensitive to hard water and limited in pH compatibility
Sulfate ester	K12	Strong foaming and degreasing, but relatively obvious defatting feel and irritation
Ether sulfate	AES	Balanced foaming, solubility, mildness, and formulation compatibility
Sulfonate	LAS, AOS, MES, FMES, SAS	Sulfonate head groups are generally relatively stable, with prominent detergency and hard-water tolerance
Isethionate / amino acid salt	SCI, amino acid-based anionic surfactants	Greater emphasis on mildness, skin feel, and compatibility with mildly acidic systems

10.2 Evaluation by Hydrophobic Chain and Raw-Material Source

The hydrophobic chain not only affects oil-removal and micellization ability, but also influences raw-material cost and supply stability.

Product	Main Cost-Related Factors
LAS	Linear alkylbenzene, benzene, petrochemical raw-material chain
AES	C12–C14 fatty alcohols, ethylene oxide, sulfation cost
K12	Lauryl alcohol, sulfation cost
AOS	Alpha-olefins, sulfonation cost
MES	Fatty acid methyl esters, oleochemical raw materials, sulfonation and post-treatment costs
FMES	Fatty acid methyl ester ethoxylates, sulfonation and functional processing costs
SCI / amino acid-based surfactants	Fatty acyl raw materials, amino acid or isethionate-type raw materials, acylation process costs

10.3 Evaluation by Key Performance Requirements

Different structures correspond to different raw-material advantages. In practical selection, the target performance should first be clarified, and the structural type should then be selected accordingly.

Target Performance	Related Representative Products
Basic detergency and cost advantage	LAS
Strong foaming and strong degreasing	K12
Balance of foam, solubility, and mildness in liquid systems	AES
High foam and hard-water tolerance	AOS
Oleochemical origin, high detergency, and hard-water friendliness	MES
Low foam, alkali resistance, emulsification and dispersion, and heavy-duty soil removal	FMES
Traditional cleansing feel and soap-based characteristics	Fatty acid soap
Mildness, skin feel, and compatibility with mildly acidic systems	SCI, amino acid-based anionic surfactants
Balanced wetting, detergency, foam, and hard-water tolerance	SAS

11 Related Anionic Surfactants and Key Raw Materials

Table 1 Upstream Fatty-Chain Raw Materials, Intermediates, and Soap-Based Carboxylates

Category	CAS No.	Aladdin Catalog No.	Name	Specification or Purity	Product Features and Applications
Fatty acid raw material	57-10-3	P753896	Palmitic Acid	Stearic acid ≤0.5%	Used as a fatty-chain structural reference for soap bases, fatty acid salts, and oleochemical-based surfactants; suitable for studies on the effects of chain length on melting point, solubility, and interfacial behavior
Fatty acid raw material	112-80-1	O1456057	Oleic Acid	European Pharmacopoeia (Ph.Eur), ≥65%	Representative unsaturated fatty acid; used for oleate salts, soap-based systems, and studies on the effects of fatty-chain unsaturation on emulsification and wetting behavior
Fatty acid raw material	57-11-4	S298767	Stearic Acid	Moligand™, C18: 98%	Representative long-chain saturated fatty acid; used for stearate salts, soap-based systems, and studies on the effects of long-chain hydrophobic structures on solubility and crystallization
Fatty acid raw material	143-07-7	L110736	Lauric Acid	GR, ≥99%	Representative C12 fatty acid; used for lauryl anionic surfactants, acyl amino acid salts, and chain-length-effect studies
Fatty alcohol raw material	112-53-8	D431501	1-Dodecanol	ACS, ≥98%	Lauryl alcohol-type hydrophobic-chain raw material; used in synthesis studies related to alkyl sulfate esters, ether sulfate esters, and fatty alcohol ethoxylates
Isethionate intermediate	1562-00-1	H105362	Sodium 2-Hydroxyethanesulfonate (SHES)	≥98%	Key intermediate for isethionate-type mild anionic surfactants; used in acylation reactions, structural design, and mild cleansing raw-material research
Soap-based carboxylate	143-19-1	S104196	Sodium Oleate	Moligand™, ≥97% (T)	Representative unsaturated fatty acid sodium soap; used in studies of soap-based emulsification, wetting, foam, and hard-water sensitivity
Soap-based carboxylate	143-18-0	P118571	Potassium Oleate	≥98%	Representative potassium soap; used in soft-soap systems, emulsification behavior, and studies on fatty acid salt solubility
Soap-based carboxylate	408-35-5	S161420	Sodium Palmitate	≥97% (GC) (T)	Representative C16 fatty acid sodium soap; used in studies of soap-based cleansing, fatty acid salt crystallization behavior, and hard-water precipitation
Soap-based carboxylate	822-16-2	S108363	Sodium Stearate	≥96%	Representative C18 fatty acid sodium soap; used in long-chain soap-based systems and studies on interfacial adsorption, foam stability, and calcium/magnesium soap scum

Table 2 Sulfate Ester, Ether Sulfate, and Sulfonate Cleansing Anionics

Category	CAS No.	Aladdin Catalog No.	Name	Specification or Purity	Product Features and Applications
Alkyl sulfate ester	151-21-3	S432157	Sodium Dodecyl Sulfate (SDS)	Anhydrous grade, ACS, ≥99%	K12 structural representative; used in studies of strong foaming, degreasing, micelle formation, protein interactions, and interfacial tension
Alkyl sulfate ester	2235-54-3	S133281	Ammonium Lauryl Sulfate Solution	30% in H2O	Representative ammonium salt of lauryl sulfate; used in studies of foam, wetting, cleansing power, and the effect of counterions on surface activity
Ether sulfate ester	9004-82-4	S196294	Sodium Polyoxyethylene Lauryl Ether Sulfate	≥25%	AES structural representative; used in studies on the effects of ethoxylated chains on hydration ability, foam, thickening, mildness, and formulation compatibility
Alkylbenzene sulfonate	25155-30-0	S592217	Sodium Dodecylbenzenesulfonate (SDBS)	Anion Active Matter, 85%	Alkylbenzene sulfonate/LAS model structural reference; used in studies of aromatic sulfonate detergency, interfacial adsorption, micellization, and anionic active-matter evaluation
Alkylbenzene sulfonic acid	27176-87-0	D106550	Dodecylbenzenesulfonic Acid (DBSA)	≥90%, mixture	LABSA acid-form raw-material reference; used in neutralization to form salts, pH control, sulfonate structure studies, and detergency-backbone research
Alkenyl sulfonate	68439-57-6	S304377	Sodium Alpha-Olefin Sulfonate	≥92%	Representative AOS raw material; used in studies of high foam, hard-water tolerance, wetting, emulsification, and the effects of inorganic salts on interfacial behavior

Table 3 Amino Acid-Based Mild Anionic Surfactants

Category	CAS No.	Aladdin Catalog No.	Name	Specification or Purity	Product Features and Applications
Sarcosinate	137-16-6	N432001	Sodium N-Lauroyl Sarcosinate	Suitable for synthesis	Representative acyl sarcosinate; used in studies of mild anionic structures, foaming, wetting, and protein interactions
Glutamate	29923-31-7	S339866	Sodium Lauroyl Glutamate	≥95%	Representative acyl glutamate; used in studies on the effects of amino acid head groups on mildness, compatibility with mildly acidic systems, and foam properties
Glycinate	90387-74-9	S1523505	Sodium Cocoyl Glycinate	30%	Representative acyl glycinate sodium salt; used in mild cleansing, fine foam, skin-feel evaluation, and formulation-combination studies
Glycinate	301341-58-2	P1523507	Potassium Cocoyl Glycinate	30%	Representative potassium acyl glycinate; used in studies of potassium amino acid-based surfactants, foam texture, solubility, and mildly acidic systems

Note: The above are representative Aladdin products related to scientific research and formulation studies. For more information on product specifications, grades, and COA, please search by “product name/CAS/catalog number” on the Aladdin website.

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