How Does Soap work? We all have been asking this question. Let’s uncover that ‘how’. So, everything around us is made up of things we call as atoms & molecules. Likewise, so are soap, water, and oils we use in our daily lives. The important part to note is that some molecules are hydrophilic, (water-loving) these molecules are attracted to water. While some molecules are hydrophobic, (water-fearing), they are repelled by water.
If molecules are hydrophilic, then they will readily mix with water.
If molecules are hydrophobic, then they will readily mix with oil.
Since we all know that water and oil do not mix, then we could also conclude that hydrophilic and hydrophobic compounds follow the same trait.
Further, we must add two more words to our vocabulary. Nonpolar compounds, like grease or oil, cannot dissolve in water. Polar compounds can dissolve in water.
How do Soaps work?
Most of what we call dirt is a mix of grease and oil which will not come off with just water, no matter how hard we try. The reason for this being that oil and grease are non-polar in nature, which means they will not dissolve in the water.
On the other side, soaps can mix with both water and oil. Why? Simply because the soap molecule has two ends, one of which is hydrophilic (polar head) that binds with water and the other one is hydrophobic (non-polar hydrocarbon tail) that binds with grease/oil.
When dirt or oil is mixed with some soapy water, the soap molecules arrange themselves into tiny clusters called micelles. The water-loving part of the soap molecules (hydrophilic) sticks to the water and points outwards, forming the outer surface of the micelle. The oil-loving parts (hydrophobic) stick to the oil and trap oil in the center where it can’t come into contact with the water molecules.
With the oil tucked safely in the center, the micelle so formed is soluble in water. As the soapy water is rinsed away at the end of the wash, the greasy dirt goes away along with it.
Did You Know?
Do you know why it is easier to clean dirty, greasy hands in hot or warm water rather than cold water? It is primarily because the fats and oils soften or melt in hot water, which allows them to attach readily to the hydrophobic end of the soap molecule. In turn, that makes it easier to rinse away.
Soap is a Natural Surfactant
A surfactant is a substance that reduces the surface tension of a liquid. Almost all cleansing products that we use in our daily lives are based on surfactants.
Surfactants are responsible for not only reduce the surface tension of the water but also, the way they are constructed (with one hydrophilic and one hydrophobic end), making them compatible with both water and oil. This property is what makes them great to be used for cleansing.
When surfactants get into action, they make the water molecules more slippery. So they are less likely to stick to themselves and more likely to interact with oil and grease present on the surface of the skin.
Does Natural Soaps Need Synthetics for Making Lather?
No, Natural soaps need no synthetic additives to create a lather or to clean because natural soap is in itself a natural surfactant. And because of this, it not only makes great bubbles and lather, but it also helps clean oily dirt from your skin — all in a natural way!
We hope that this post was helpful in letting you know on how soaps work.
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