Putting the FACT in Surfactants: Technical Details
Surfactants are found in industrial processes, personal care products and household cleaners from detergents to disinfectants. Whether bio-based or synthetic, surfactants are multifunctional. They can serve purposes ranging from getting those stubborn stains up, to washing hair or cleaning countertops. But what are surfactants and what is their purpose within product formulations?
What is a Surfactant?
The key to understanding surfactants is to look at their primary function, which forms the basis for their name. The word “surfactant” is an abbreviation of its role in chemistry as a surface active agent.
Surfactants as Surface Active Agents
Surface active agents have the unique ability to decrease the surface or interfacial tension between two liquids, such as water.
For example, water molecules form strong bonds with each other creating impressive surface tension. These bonds and resulting tension are the reason why water bugs can “skate” across the surface of a pond. Surfactants decrease the interfacial tension of water by interfering with the hydrogen bond between the water molecules.
By reducing the surface tension of the water (or other liquids), surfactants help foster a stable, finely distributed mixture.
Surfactants Improve Wettability
Surfactants also increase liquids’ spreading and wetting properties—known as wettability.
Surfactants allow products, such as detergents, to better penetrate and dissolve surface soils, increasing their effectiveness
The Hydrophilic Head and Hydrophobic Tail of Surfactants
A surfactant has molecules made up of water-loving regions and water-fearing regions. The water-loving region is known as the hydrophilic head. The water-fearing region is known as the hydrophobic tail.
When a surfactant encounters the water’s surface, the water-loving hydrophilic head will point into the water’s surface. The water-fearing hydrophobic tail will point out.
Surfactants Break Interfacial Bonds with Micelles
When the molecules have saturated the entire surface, the leftover molecules form specialized structures called micelles. Micelles enable surfactants to break interfacial bonds. The smaller the micelle size, the further these micelles can move down into surface cracks and pores.
The Molecular Force of Surfactants Reduces Surface Tension
During this process, new bonds are formed. The molecular force between a surfactant molecule and a water molecule is lower than the force between two water molecules. This reduces surface tension and allows for deep penetration.
Formulators leverage the unique molecular properties of these surface active agents, or surfactants, to improve the performance of products such as lotions, detergents, and degreasers.
The Use of Chemical Surfactant Ingredients
There are many different classes and families of surfactants, each with their own unique applications.
Synthetic or chemical surfactants currently dominate the market. Historically, most industries have relied upon these traditional surfactants, which include:
- sodium lauryl sulfate
- cocamidopropyl betaine
- …and others
These common surfactants rely on nonrenewable resources such as petrochemicals. While some of them boast high performance and great foaming capabilities, there are downsides. Chemical surfactants may cause skin irritation, they are not biodegradable and they can negatively impact the environment.
Chemical surfactants also have simple molecular structures, making them not as multifunctional within product formulations.
Palm Oil-based Surfactants
Other types of surfactants are based on palm oil derivatives, such as:
- sodium laureth sulfate (SLES)
These palm oil-based surfactants were initially seen as sustainable alternatives to chemical surfactants. However, the palm oil industry has a multitude of environmental issues, including contributing heavily to tropical deforestation.
The downsides of synthetic chemical surfactant ingredients have increased the demand for bio-based and natural surfactants. These alternative options include:
- Alkyl Polyglucosides (APGs)
While considered bio-based, APGs get their carbon from plant-based sources, including palm oil. They are also made through carbon-intensive synthetic chemical conversions. Their performance and functionality vary greatly depending on the fatty acid used in their production.
Because of these factors, many formulators are turning towards biosurfactants.
Biosurfactants: The Natural Surfactant Alternative
Biosurfactants alleviate the concerns consumers, formulators and marketers have with SLES, APGs and other ethoxylated or natural surfactants.
What are Biosurfactants?
Biosurfactants are a specific subcategory of bio-based surfactants made from microorganisms like bacteria, yeasts and fungi. They are produced through natural processes such as fermentation. Biosurfactants feature complex molecules, which provide equal or better performance than synthetic chemical surfactants in any number of applications.
One of the leaders in biosurfactant production is Locus Performance Ingredients (Locus PI). The company uses patented fermentation methods and agricultural raw materials to produce novel biosurfactants. These biosurfactants are in the glycolipid class and include sophorolipids.
Benefits of Sophorolipids
Locus PI’s sophorolipids have unique molecular structures that provide better surface and interfacial tension reduction, resulting in higher performance and multifunctionality. They can replace traditional and partially bio-based surfactants in nearly all applications. These sophorolipids also help decrease usage rates, or in other words, require less of the ingredient to achieve the desired outcome.
In addition to better efficacy, Locus PI’s sophorolipid biosurfactants offer a multitude of sustainability benefits. They have a near-zero carbon footprint and the highest renewable carbon index rating. Each sophorolipid is USDA certified as 100% biobased and readily biodegradable. The biosurfactants are non-GMO, sulfate-free and palm oil-free. They have no Proposition 65 issues, 1,4-dioxane or ethylene oxide.
Locus PI’s biosurfactants have been proven to be highly effective as surface active agents in product formulations. The sophorolipids accelerate the adoption of more environmentally friendly yet effective natural surfactants in everyday detergents, cleaning products, industrial applications and more.