How do detergents act as cleaning agents? – The science unveiled

They’re everywhere, yet most of us don’t really know how they work – just that they work. Cleaning detergents are chalk full of chemicals that are engineered to remove certain kinds of stains, particles and impurities to help keep your home or establishment squeaky clean. But, just how much do you know about how cleaning detergents are able to do what they do?

In this blog, we’re going to lift the veil on how cleaning detergents remove all those tough stains that give you nightmares. The science is really simple once you get to understand it, so let’s dig in!


Detergents and surfactants explained

To understand how cleaning detergents work, we first need to understand what they are, as well as the role that surfactants play in helping detergents do their jobs. 


What are detergents?

We often use the words “soap” and “detergent” interchangeably, but in truth, they’re two different things. A detergent can be defined as a chemical substance you use to break up and remove grease and grim, while soap is simply a type of detergent. 

Soap has a long history and was originally made up of purely natural products like goat’s fat and wood ash. Today, detergents are more likely to be a mix of synthetic chemicals and additives cooked up in huge chemical plants and, unlike traditional soap, they’re generally liquids instead of solids. 

Detergents are utilized in everything from hair shampoo and garments soap powder to foam and stain removers. The most important ingredients in detergents are chemicals called surfactants — let’s find out what those are and why they’re important.


What are surfactants?

Water gets you wet, but it doesn’t get you nearly as wet as it should. That’s because H2o has something called surface tension. Water molecules prefer their own company and so tend to stay together in water droplets. 


For example, when rain falls on a window, it doesn’t wet the glass uniformly; instead, it sticks to the surface in distinct droplets that gravity pulls down in streaks. To help water wash certain things better, we have to reduce its surface tension, so it wets things more uniformly –that is precisely what a surfactant does. The surfactants in detergents improve water’s ability to wet things, cover entire surfaces, and seep into dirty clothing fibres.

With surfactants, one end of their molecule is attracted to water, while the other is attracted to dirt and grease. Thus, surfactant molecules help water to get a better hold of grease, break it up, and wash it away.


How do detergents work?

The cleverest a part of a washing machine isn’t the drum, the drive belt, the electrical motor that spins it around or the electronic circuit that controls the program – no. Rather, it’s the detergent (soap powder or liquid) you put in right at the beginning of every washing cycle. 

Water alone can’t clean clothes because it can’t effectively attach to molecules of grease and dirt. Detergent is different. The surfactants, it contains are made from molecules that have two different ends. One end is strongly attracted to water, while the opposite end is attracted to oily substances like grease.

Let’s say for example you got your favourite tracksuit covered in grease; when you throw it into the washing machine with detergent, this is what happens:


  1. During the wash cycle, the surfactant mixes with water.
  2. The grease-loving ends of the surfactant molecules start to connect themselves to the dirt on your tracksuit. The tumbling motion beats your tracksuit about and breaks the dirt and grease into smaller, easier-to-remove pieces.
  3. During the rinse cycle, water molecules moving past attach themselves to the water-loving ends of the surfactant molecules.
  4. The water molecules pull the surfactant and dirt away from the tracksuit. During the final spin, the dirty water flushes away, leaving your jeans clean again!


The science is really simple, right!? Now that you know how detergents work, you’ll have a better idea of the ideal types of detergents you need for your specific needs. Get in touch with us and we’ll give you a hand with getting the right detergents – we’re happy to help!