Why does leather stick to skin on hot days?



When it’s a hot day and your sat or laying on leather seats, why when you go to get off does leather stick to your skin. Ive never had it with any other material. Ive always wondered why this happens.

In: Chemistry

The stickyness in this scenario as far as I remember is a result of salt from the sweat and sweat itself creating colloid systems which create strong bonds between each other and between salt ions. Water itself can’t create strong enough bond to stick as much, but salt from two very complicated surfaces might do a trick?

But I’m a process engineering graduate so I might be wrong here

Adhesion is a phenomena closely tied to cohesion. Cohesion is the tendency for liquids to stick together like when droplets of water form. When you have something porous enough for the liquid to fall into the pores, the liquid acts as an adhesive by filling the pores and attaching itself to other molecules of its type through cohesion.

With leather, you are sweating, forming a liquid barrier between you and the leather. That sweat is filling the pores of your skin and the leather and binding you to it like an adhesive. Just like when you put a piece of paper on water on a wood table, the paper becomes stuck to the table.

If you have pores that are too small for the liquid to fill, the fluid creates a protective barrier that allows two materials to glue over the opposing sides of the fluid; this is called lubrication. Lubricants and adhesives are roughly two sides of the same coin. At least according to high school physics. I’m quite positive there are exceptions to the rules in higher level physics.

It definitely happens with other materials, like vinyl. The trick is that materials that are very porous, like fabric, will wick away the moisture and not allow the moisture to create the bond like the above answer.

*shutter* that velcro like sound when you stand up from a chair or booth in a skirt when you are trying to be elegant on a date. *sigh*