October 9, 2023
What are Surfactants and What Do They Do?
Surfactants exist in almost every cleaning product and are essential in removing soils. Knowing what surfactants are and how they behave can help us understand how to properly use them to achieve the best results, making facilities clean and presentable.
In this blog we will explain what a surfactant is, what they do, and how they effect cleaning.
What are Surfactants?
Surfactants are a main compound of cleaning solutions. They are active agents that are responsible for removing soils from surfaces. They are extremely versatile and help to reduce the amount of tension so that water can spread out across a surface. This is because the molecule is made of two parts – a head and a tail.
The head is hydrophilic (‘water-loving’) and is attracted to water, whilst the tail is hydrophobic (‘water-hating’) and is repelled by water.
What Do Surfactants Do?
When there is a high concentration of surfactant molecules, they form a circular structure known as a micelle. The heads of the surfactants fringe the edge of the circle, where they are exposed to water, whilst the tails gather in the centre where they are protected away from water. The tails in the micelle attract and trap soils, whilst the heads lift them from the surface and into the solution. This behaviour is called emulsification.
Once soils enter the micelle, they do not return back to the surface. This is why surfactants are so successful at removing dirt and are widely used in many products and detergents in the cleaning industry.
Types of Surfactants
There are different types of surfactants: non-ionic, anionic, and zwitterionic. The type depends on the charge of the head of the molecule.
This has no charge and is adept at removing organic soils. They make up dual-action and multi-purpose cleaners and can be used to form low-foaming detergents.
Cationic & Anionic
Cationic have a positive charge, and anionic has a negative.
Negatively charged surfacants are very good at suspending large amounts of soil. A washing up liquid contains anionic surfactants and can keep cleaning even when the dishwater is heavily soiled.
Cationics tend to absorb onto surfaces due to their positive charge. They perform well in fabric softeners and hair conditioners. Cationic surfactants can also be used in disinfectants as antimicrobial agents by adsorbing onto the surface of bacteria.
These surfactants have both a positive and negative charge and it makes them very versatile. This is known as zwitterionic.
They are commonly used as ‘secondary surfactants’, in that small quantities are used to modify the characteristics of the main anionic, nonionic or cationic surfactants.
It is important to note the effect that over, or underuse of cleaning chemical and surfactants have on results.
When under-dilution occurs, there is an abundance of surfactants. When left behind as residue on flooring, they will continue to attract more dirt. This, in turn, causes surfaces to become dirtier sooner.
Vice versa, where there is over-dilution, there are not enough surfactants to pull dirt from a surface. This leaves unsatisfactory results.
Measuring out the correct amount of detergent will achieve the best cleaning results, reduce waste and save on the cost of over-purchasing cleaning chemicals.
A cleaning solution in concentrated form can be measured when diluted in water. For instance, it may require 1 part chemical in 32 parts of water (1:32). The dilution rate is unique to each product and can be found on the label. The provider should provide guidance.
If there are several chemicals being used all with different dilution rates, wall charts are a great way of managing this. Additionally, dosing systems will ensure the correct measurement of chemical for dilution.
To wrap up, it is beneficial to understand surfactants as they are found in many of our cleaning chemicals.
Having knowledge of how they function can help to ensure proper use to achieve the best possible results.
By measuring your cleaning chemical, you control the amount of surfactants during the cleaning process. Not only does this influence the level of cleanliness, but it also helps to reduce waste and saves on the cost of chemicals.