Hand washing is simple, quick, and crucial to keeping you safe and healthy. You've watched soap wash stubborn oil and dirt off your hands, body, and clothing. Do you know how it does this? Keep reading to learn how soap actually works to keep surfaces clean!
What is soap made of?
Soap is made up of fatty acids and a single soap molecule which consists of a hydrophilic head and hydrophobic tail (as seen in the diagram below). The hydrophilic head is attracted to and can dissolve in water, while the hydrophobic tail repels water.
So how does it work?
When you come into contact with oils and germs, those oils mix with the natural oils on the surface of your body. You've probably heard that water and oil don't mix, so when you rinse your hands without soap, the water slips right off and doesn't take any of the oils away with it. This is where soap comes in handy.
The hydrophobic chain of tails attaches onto the oil, while the hydrophilic heads stick out into the water. This creates a droplet of oil, a micelle, that is separated and then distributed into the surrounding water instead of being left clinging to your skin, body, or clothing. After the soap separates the oil from the surface, the oil can be rinsed off by the water.
I hope you learned about the role of chemistry behind washing your hands. Stay safe and healthy!
Written by: Ashlee Liu
References:
Kallen, Laura. “How Does Soap Actually Work?”DefeatDD, 28 Aug. 2019, www.defeatdd.org/blog/how-does-soap-actually-work#:%7E:text=When%20you%20wash%20your%20hands,stubbornly%20clinging%20to%20your%20skin.
Comments