Soap makes water ‘wetter’

Automatic soap dispensers can be automatically annoying. Hey, I exist soap dispensing god! I can’t think of any other thing I can possibly do with my soiled hands in front of your “sillitupid” sensor to prove I’m here!

Is skirmishing with the insensitive sensors for soap actually worth it? As a teen trying to be cool, but not swear in front of his parents might say, abso max hecks to the yes. Soap of all types, including hand soap, household detergents and agricultural cleaners, make the cleaning process much more effective.

The problem with using just water is that it’s not “wet” enough, and is surprisingly ineffective at getting things slippery. Soap makes water “wetter”. The problem is water’s surface tension, which by the way, enables water bugs to skate on water instead of sink into certain doom with the fishes.

All soaps work by lowering water’s surface tension. Science Shorts describes the process pretty well, using laundry detergent as an example: “Detergent molecules are like little tadpoles. The heads are attracted to the water molecules by a small electric charge, while the tails, which are chemically very similar to grease, are repelled by water molecules. So the tail of the detergent molecule attaches itself to the grease. With their heads attracted to the water, and their tails embedded in the grease, the detergent molecules hold the water and the dirt together, until they float away as the clothes are agitated.”

Want a bit more of a “sciencey” explanation? Here’s one from Science Focus:  “(Soap molecules) consist of a hydrocarbon chain, with a sodium or potassium atom at the end. The hydrocarbon end is attracted to oil and repels water, whereas the other end attracts water. When you wash your hands, oily dirt particles are surrounded by soap molecules with their water-loving heads facing outwards. This breaks up the dirt and lets it wash away in the water.”

So your mother, who may have been shockingly wayward wrong on some things, was actually right about this one. Use soap.

For more on Neogen’s agricultural cleaners, click here.

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