On Surfactants & Soap (1 Viewer)

[emilios]

When asked to define a surfactant, you'd usually say something to the effect of "a surfactant is a substance that reduces the surface tension of the liquid it is dissolved in".

When talking about the cleaning action of soap, we say the long hydrocarbon chain attaches to the greasy surface and the anionic head to the water molecules. When agitated, 'micelles' form and are suspended in solution, effectively removing the grease.

So my question:

How does reducing the surface tension of the water play into this?

Does it contribute at all? Why a surfactant ion if I can effectively describe the whole process without having to mention surface tension?

 

[emilios]

Bump!

 

[QZP]

Not only do surfactants reduce the surface tension of a liquid it is dissolved in, it reduces the interfacial tension between two liquids to allow them to better mix.