Science
Fact-checked

At AllTheScience, we're committed to delivering accurate, trustworthy information. Our expert-authored content is rigorously fact-checked and sourced from credible authorities. Discover how we uphold the highest standards in providing you with reliable knowledge.

Learn more...

What is a Surfactant?

Mary McMahon
Mary McMahon
Mary McMahon
Mary McMahon

A surfactant is a compound that lowers the surface tension of a liquid, increasing the contact between the liquid and another substance. There are a wide variety of these compounds that work with oil, water, and an assortment of other liquids. Many companies manufacture a range of surfactants for various purposes, ranging from soaps to inks. They are also sometimes referred to as “wetting agents.”

The term is a compound of “surface acting agent,” referring to the fact that these substances interact with the surface of a liquid to change its properties. They work through a process known as “adsorption,” which means that they accrete on the surface of a liquid, creating a film that reduces its surface tension.

Dish soap contains a surfactant to make cleaning easier.
Dish soap contains a surfactant to make cleaning easier.

One of the most famous surfactants is soap, which is used to break the surface tension of water so that it can penetrate more fully. The foaming action of soap helps water get under dirt and grease on surfaces like dishes, hands, and fabrics, allowing the water to carry the dirt away. As anyone who has tried to wash without soap knows, the high surface tension of plain water makes cleaning very difficult.

Shaving cream is a surfactant.
Shaving cream is a surfactant.

Surfactants can also work as lubricants, as is the case with shaving a cream, which makes it easier to run a razor along the skin to remove unwanted hair. They are also used in sanitizing products, anti-fogging liquids, adhesives, emulsifiers, and fabric softeners, among numerous other substances. In some cases, these compounds may be toxic or pose a health risk, depending on the materials they contain, and it is a good idea for users to read labels to make sure that they are being used properly.

Soap is a common surfactant.
Soap is a common surfactant.

The term is also used in the medical community to refer specifically to a substance secreted by the cells that line the lungs. Pulmonary surfactant makes it easier for people to breathe by reducing surface tension in the lungs. Without this substance in the lungs, people would have trouble breathing, and their breathing would be much noisier. Many of the respiratory problems in premature infants are caused by lack of surfactant, and some rare lung diseases can also interfere with its production and function.

Mary McMahon
Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a AllTheScience researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

Learn more...
Mary McMahon
Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a AllTheScience researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

Learn more...

Discussion Comments

anon996008

Will a mix of light weight oil and soap bond to a solution of Alligare (permertherin) and increase it' effect? --sayger2

anon279097

@Turkay1: Our bodies do produce surfactant continuously, so babies with surfactant deficiency do eventually produce their own surfactant. They can be given surfactant from cow or pig lungs to get them through until they produce it themselves.

Also, if preterm delivery is predicted, the mother can be given steroids during pregnancy, which will help to mature the lungs and speed up the surfactant production prior to delivery.

burcinc

I thought that surfactant was only good as a cleaning agent. But I read an article the other day that talked about the use of surfactant in oil recovery from petroleum reservoir rocks. When a petroleum reservoir is depleted, they flood it with chemicals containing surfactant which helps get out the remaining oil. This makes sense. I actually knew that they use surfactant to clean out beaches and land after oil spills. It doesn't sound too great for animals and plants, but oil is a hard thing to remove.

candyquilt

My best friend's son is now four years old and has asthma. When he was born, doctors said that his lungs had surfactant deficiency. It was surprising to find out that baby starts to produce surfactant at 22 weeks, in the mother's womb. Steven was able to produce some but not as much as most babies.

His pediatrician doesn't think that this is the reason for his asthma symptoms now. We know that he is allergic to pollen and such, but if surfactant makes it easier for people to breathe, this must be the main reason for his asthma. It's not too bad, and we are grateful for that. But what I am wondering is, are there any medicines to help produce surfactant?

If we can only produce it while we are in the womb, it's just sad that many people will have respiratory problems their whole lives because of it. If not later after birth, can something be done for unborn babies to produce enough surfactant? It's great that these problems can be detected early on but if there is nothing we can do about it, what's the point?

ddljohn

My mom says that the soaps that they used for laundry when she was young did not work too well because it did not have surfactants. Soap used to leave residue on the clothes and eventually wore out the fabric apparently. This must have been one of the reasons why our laundry detergent today has surfactants. But regular detergents that we use today are bad for the environment because they don't break down and they are not renewable either. I'm not too sure that detergents have been a good replacement for soap for that reason.

I actually use an environmentally safe laundry detergent. It works really well, does this mean that it has surfactant also?

Post your comments
Login:
Forgot password?
Register:
    • Dish soap contains a surfactant to make cleaning easier.
      By: Artanika
      Dish soap contains a surfactant to make cleaning easier.
    • Shaving cream is a surfactant.
      By: Ruslan Solntsev
      Shaving cream is a surfactant.
    • Soap is a common surfactant.
      By: CandyBox Images
      Soap is a common surfactant.
    • Many respiratory problems in premature infants are caused by lack of surfactant.
      By: massimhokuto
      Many respiratory problems in premature infants are caused by lack of surfactant.
    • The foaming action of soap help water get under dirt on hands.
      By: tab62
      The foaming action of soap help water get under dirt on hands.