Sodium Lauryl Ether Sulfate

Catalog	BBC68891383
CAS	68891-38-3
Synonyms	Poly(oxy-1,2-ethanediyl), α-sulfo-ω-hydroxy-, C12-14-alkyl ethers, sodium salts
Boiling Point	≥100 °C
Flash Point	min. 94 °C
Density	1.08 g/mL
Appearance	Hazy, viscous liquid
Active Content	27.5%
EC Number	500-234-8
INCI Name	Sodium Laureth Sulfate

Case Study

Sodium Lauryl Ether Sulfate Used for the Preparation of Chitosan-Based Microcapsules for Vitamin E Delivery

Budinčić, Jelena Milinković, et al. Carbohydrate Polymers 251 (2021): 116988.

Sodium lauryl ether sulfate (SLES), an anionic surfactant, has demonstrated significant potential in the microencapsulation of hydrophobic active ingredients, particularly in cosmetic and pharmaceutical formulations. In this study, SLES was employed alongside chitosan (Ch) to form a stable polyelectrolyte complex, serving as the wall material in the microencapsulation of vitamin E.
Microcapsules were fabricated via complex coacervation followed by spray drying. Chitosan/SLES complexes were prepared at a 1:2 mass ratio under acidic conditions (pH 4.0), where chitosan exhibited strong cationic behavior (zeta potential +36.1 mV). The emulsions-consisting of vitamin E dissolved in medium-chain triglycerides (MCTs) and stabilized with the Ch/SLES mixture-underwent high-shear homogenization and subsequent drying at 160 °C inlet and 100 °C outlet temperatures.
This process yielded stable microcapsules with an average diameter of 6.85 ± 0.213 μm and a high encapsulation efficiency of 73.17 ± 0.64%, even in the absence of aldehyde-based cross-linkers. The results highlight SLES as a benign alternative to traditional, often toxic, cross-linking agents, enabling safe and effective encapsulation of lipophilic vitamins.
This work underscores the utility of sodium lauryl ether sulfate in designing environmentally friendly, biocompatible microcapsule delivery systems suitable for cosmetic and therapeutic applications.

Sodium Lauryl Ether Sulfate Used for the Stabilization of Chitosan-Based Oil-in-Water Emulsions

Milinković, J., Petrović, L., Fraj, J., Bučko, S., Katona, J., & Spasojević, L. (2018). Colloids and Surfaces A: Physicochemical and Engineering Aspects, 557, 9-13.

Sodium lauryl ether sulfate (SLES), a widely utilized anionic surfactant, plays a crucial role in stabilizing oil-in-water (O/W) emulsions through its interaction with oppositely charged polyelectrolytes. In this study, SLES was combined with chitosan (Ch), a cationic biopolymer, to investigate their interfacial behavior and its influence on emulsion stability.
By forming Ch/SLES complexes under acidic conditions (pH 4), the interfacial tension at oil-water interfaces was significantly altered, promoting enhanced stabilization of emulsions. Medium-chain triglycerides (MCTs) were identified as the most suitable oil phase among three tested oils due to favorable adsorption behavior. Emulsions containing 20% MCTs and stabilized with varying Ch:SLES mass ratios (100:1, 1:3, 1:10) were prepared using high-shear homogenization.
The study revealed that the Ch/SLES interaction modifies the adsorption layer at the oil droplet surface, influencing emulsion droplet size, distribution, zeta potential, and long-term stability. These findings provide a mechanistic understanding of how polymer-surfactant interactions contribute to the stabilization of colloidal systems.
SLES, in conjunction with chitosan, proves to be a versatile, efficient, and biocompatible emulsifying system-making it a promising candidate for use in pharmaceutical and cosmetic formulations, particularly for microencapsulation applications requiring stable dispersed systems.

Sodium Lauryl Ether Sulfate Used for Enhancing Foam Stability in Mixed Surfactant Formulations with Tea Saponin

Li, Weixin, et al. Surfaces and Interfaces 29 (2022): 101707.

Sodium Lauryl Ether Sulfate (SLES), a widely used anionic surfactant with ethoxylated chains, demonstrates significant synergistic effects when combined with natural surfactants. This study explores the interfacial behavior and foam stability of SLES in binary mixtures with tea saponin (TS), a natural glycoside, to improve the performance of cosmetic formulations and reduce reliance on synthetic surfactants.
By analyzing interfacial tension (γ) and foam behavior across various conditions, it was found that small additions of TS significantly lowered the critical micelle concentration (cmc) of the SLES/TS mixture and enhanced foam stability. Thermodynamic analyses revealed strong synergistic interactions between the two surfactants, reducing surface tension more efficiently than either component alone.
The improved foam stability was attributed to reduced bubble size and increased contact angle, resulting in more robust foam films. Remarkably, the AES/TS mixtures maintained their interfacial activity under a wide range of conditions, including elevated temperatures, the presence of mono- and divalent cations (Na⁺, Ca²⁺, Mg²⁺), and across a broad pH spectrum (3-11), highlighting the system's environmental resilience.
This work underscores the potential of Sodium Lauryl Ether Sulfate in combination with bio-based surfactants for developing high-performance, eco-friendly foaming systems applicable to personal care and household products.