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Magic Molecules Surfactants in Action

Team Chemical Market

29 Feb 2024

Introduction

In the intricate tapestry of daily existence there exists a silent protagonist, scarcely noticed but wielding profound influence - Surfactant. In their presence barriers dissolve and boundaries blur, displaying a type of magic. Disparate substances coalesce harmoniously in their proximity. They permeate the very essence of modern life by their use in a myriad of consumer products. In this article, we introduce you to the basics of this wonderful family of molecules. This article describes in short, Surfactant properties and Surfactant applications.

Background

Surfactants - a short form for surface active agents, consist of molecular chains. These compounds lower the surface tension between two substances such as between liquid and solid or between two solids. A majority of these types of molecules have a water-attracting part ( hydrophilic) and a water-repelling part ( hydrophobic). Each of the molecules has a head and a tail. If the head carries a positive electrical charge it is termed a Cationic surfactant. However, if it is negative, it is called an Anionic surfactant. Some carry no net charge and are termed non-ionic surfactants. Other important categories are Amphoteric and Biodegradable types. The above properties enable a surfactant to form a layer between surfaces, effectively reducing surface tension. A classic example of this application is the use of detergent to remove dirt from clothes. Dirt sticks to clothes, and the detergent lowers this stickiness ( surface tension), allowing water to wash it away. In the following paragraph, we will describe some of the common Types of Surfactants and their usage.

Common Surfactants

Anionic Surfactant - They posses a positively charged head group when dissolved in water. Examples include Sodium Lauryl Sulphate ( SLS) and sodium dodecylbenzene sulfonate (SDBS). They are used in body washes, laundry detergents, toothpaste, and shampoos.
Cationic Surfactant - Characterized by a positively charged head when dissolved in water, examples include Cetyltrimethylammonium bromide (CTAB) and cetylpyridinium chloride (CPC). They are frequently employed as emulsifiers in personal care products like hair conditioners and fabric softeners.
Non-Ionic surfactants - They do not carry a net charge when dissolved in water. Examples include Polysorbate 20 and Alkyl poly glucosides ( APGs). They are milder on the skin and cause less irritation compared to Anionic and Cationic Surfactants. Used as an emulsifier in cosmetics, medical care, and pharmaceutical products.

Another important Surfactant is Sorbitan Monostearate which is derived from Sorbitol and Stearic acid. Also known as Span 60, it is an emulsifier and a stabilizer. Used in ice cream production, the emulsifier distributes the fat molecules evenly, resulting in an even texture and preventing the formation of ice crystals. Stabilizers prevent the melting of the ice cream too quickly.
Amphoteric Surfactants - They have both positive and negatively charged functional groups in their molecules. One example is Cocamidopropyl betaine (CAPB), utilized as a foam booster in mild cleansing formulations like baby shampoos, face cleansers, and hand soaps.
Biodegradable Surfactant - These surfactants can be broken down into simple compounds by natural processes. They reduce the Environmental impact of Surfactant usage. Alkyl polyglucosides (APGs), used in household cleaners are an example. Other prime examples are some ethoxylated surfactants, used in pharmaceuticals as emulsifiers, stabilizers, personal lubricants, and spermicides.

Raw Materials

Some of the raw materials used in Surfactant Formulation are listed below :

Alcohols - Both natural and synthetic types, including Fatty lauryl and Cetyl alcohol.
Fatty acids - Derived from natural sources from vegetable oils and animal fats for the production of lauric, oleic, and stearic acids.
Sulfur trioxide - Including its derivatives and with the process of sulphonation, a category of sulphonated Surfactants is produced.
Alkyl Halides - Bromides and chlorides of this group are used in the synthesis of Cationic Surfactants.
Amine Compounds - Alkinolamines are used in the production of amphoteric Surfactants.
Sodium and Potassium Hydroxides - Used in the process of saponification, these alkalis are combined with fatty acids to synthesize soap-based Surfactants.

Standards

Some of the Surfactant properties and Surfactant applications have been detailed above. A few of the Indian Standards pertaining to Surfactants are listed hereunder:

IS 7884    - Shampoo Surfactant based.
IS 4955    - Household laundry detergent powders.
IS 3986    - Sodium Lauryl Sulphate for Cosmetic Industry
IS 11487 -Sodium Lauryl Ether Sulphate for Cosmetic Industry.
IS 4956    - Synthetic detergents for Industrial purposes ( Anionic Detergents)
IS 7597   - Surface Active Agents - Glossary of terms

Conclusion

From the refreshing lather of shampoo in the mornings, to the meticulous cleaning rituals of household chores, to the ice creams we binge on, to the ultra smooth baby creams, Surfactants are everywhere. They have woven themselves unassumingly into our lifestyles. However, it is imperative to acknowledge their potential contribution to environmental degradation. Addressing this concern remains an ongoing endeavor for humanity, ensuring that the benefits of surfactants are balanced with responsible usage and Environmental stewardship.