Last Updated on March 14, 2023 by Verna Meachum

Have you ever wondered how oils in hair products stay so well combined with other ingredients in hair products? Emulsifiers are the answer!

Emulsifiers for hair products are ingredients used to make an emulsion. They are chemical compounds that can separate oil into water and water into oils. They are also known as emulsifying agents and play a vital role in hair care formulations and manufacturing processes.¹

In this comprehensive guide, we’ll look into the fundamentals of emulsifiers and how they work to create an emulsion. Additionally, you will learn about some of the most commonly used emulsifiers that are employed in hair care products.

What are Emulsifiers for Hair Products?

Oil and water are two elements that simply will not mix – oil does not dissolve or disperse in water, nor does water dissolve or disperse in an oil medium.

If you were to mix oil into water, even with vigorous shaking oil and water will never combine to create a homogeneous liquid- the two distinct liquids eventually separate.

How can we effectively blend the oil and water layers together? We know that oil, being less dense than water, floats on top while water, being the denser fluid remains at the bottom.

Water, being universal and polar, allows only similarly-polar compounds to dissolve in it. Blending non-polar oily liquids into the water can be a tricky task due to the higher surface tension of the oil and its tendency to resist mixing.

Surface tension is the amount of force/energy water molecules fight against breaking their surface barrier. To successfully disperse oil into the water and ensure they don’t separate and stay homogenous for a longer time, the surface tension of the water must be reduced.

Chemical compounds that can lower the surface tension of water are called surfactants or emulsifiers. By blending oil with a suitable emulsifier, you can create an even mixture referred to as an “emulsion.”² 

Hair products rely heavily on emulsions, which deliver active ingredients to both the hair and scalp.

Conditioners, styling creams, waxes, and pomades are all unique examples of emulsified mixtures that combine oils with a water phase using multiple emulsifiers for maximum compatibility.³

List of Commonly Used Emulsifiers For Hair Products

Anionic emulsifiers

Cationic emulsifiers

Non-Ionic emulsifiers

Due to their higher efficacy and low dosage usage needed to stabilize a product, they are often the most abundant and commonly used emulsifiers in hair and skin care products.

The number (n) in the above list denotes the degree of ethoxylation. It is the number of molecules of ethylene oxide per one molecule of emulsifier compound.

For example, Cetareth-10 means, it contains 10 molecules of ethylene oxide. The higher the number of ethoxylation, the more hydrophilic (water-loving) a given emulsifier will be.

What are Co-emulsifiers?

Co-emulsifiers are the chemical ingredients of a formulation, working in tandem with the main emulsifier to maximize product stability and improve aesthetics.

Not only do they boost the emulsification process, but also make it simpler for products to be applied evenly on skin or hair.

These chemical ingredients enhance performance significantly and ensure that all aspects of a formulation come together in perfect harmony.

Making Emulsion: Emulsifiers in Action

An emulsion is a homogeneous mixture of oils in water. In emulsion science, oil components of a formulation are called the “oil phase” while water or water-soluble ingredients are called the “water phase”.

Emulsifiers can be added to either the oil phase or water phase depending upon their melting point and solubility.

Both phases are mixed at an appropriate temperature (generally 70-80 for commonly used hair care formulations).

The mixing speed “rounds per minute” ranges from 1000 – 2000 rpm. The addition of emulsifiers reduces the surface tension of water and energy barrier while high temperature and rapid agitation facilitate molecular interaction.

The emulsification process reduces the particle size of the oil phase. This process results in a white milky liquid which gains viscosity during the cooling process.

The viscosity of the final emulsion product depends on a combination of formulation ingredients, choice of emulsifiers, and oils or waxes used in the oil phase.

Through emulsification, oil and water are effectively combined to maintain stability throughout the product’s shelf life.

Emulsifiers’ Role in Hair Products

The majority of hair care items are emulsions, such as conditioners, deep conditioning masks, treatments, styling creams, and pomades.

Furthermore, hair coloring creams, color developers, hair relaxers, and perms also come as creams. They are all emulsions containing several oils, butter, or waxes emulsified in water using different emulsifiers.

The extensive selection of products demonstrates the critical significance of emulsions, emulsion making, and emulsifiers. 

Emulsions containing small droplets of oils or butter make it easier to apply these lubricants on the hair or scalp, allowing for a uniform coating.

By combining oils into an emulsion, their application and penetration into the hair fiber become easier and more effective. This is precisely why many skin and hair care products choose to utilize an emulsion as their delivery system.

Can you substitute one emulsifier for another? 

Yes! However, it comes with certain conditions.

Changing an emulsifier and replacing it with a substitute depends upon the nature of the oils used in the emulsion and their polarity level.

It also depends upon the desired results of the end product i.e. its viscosity, texture, and aesthetic feel.

For non-ionic emulsifiers, a table of hydrophilic-lipophilic balance (HLB) is available and frequently used by formulators to find a substitute. 

Do emulsifiers dry out the hair? 

Not necessarily!  Most of the emulsifiers used today are gentle, mild, and skin-friendly.

Recent advancements in emulsion science have developed novel, high-performance, and multi-functional emulsifiers that not only manufacture emulsions but also provide emollience and hair conditioning, and moisturization.

Summary

Emulsifiers play a significant role in emulsion-based hair care products. They are the ideal ingredients for dispersing oil in water and vice versa.

Not only do they stabilize products, but also provide a unique texture, and aesthetic features, and aid in the delivery of active ingredients.

All types of hair creams, conditioners, or styling waxes rely on suitable emulsifiers to come to life as perfect emulsions!

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References

1. Silva, L.; Tonkovich Anna, L.; Lochhead Robert, Y.; Qiu, D.; Pagnatto, K.; Neagle, P.; Perry, S.; Lerou, J., Advanced Emulsions: Enabling Advanced Emulsion with Microchannel Architecture. In Cosmetic Nanotechnology, American Chemical Society: 2007; Vol. 961, pp 83-96.

2. Sjoblom, J., Emulsions and Emulsion Stability: Surfactant Science Series/61. CRC Press: 2005.

3. Kozlowski, A. C., Formulating Strategies in Cosmetic Science. Allured books: 2009.