Sorption isotherm

Imagine you have a sponge sitting in a cup of water. If you take the sponge out and squeeze it, you will see water coming out of the sponge. The more you squeeze, the more water comes out. But what happens if you want the sponge to just hold a little bit of water, like a tiny drop?

That's where sorption isotherm comes in. It is a way to measure how much of a substance (like water) a material (like a sponge) can hold or release at different levels of humidity or temperature. Just like you might squeeze the sponge to see how much water comes out, scientists can use special machines and tools to test how much of a substance a material can absorb or release in different conditions.

The results of these tests are plotted on a graph called a sorption isotherm. The graph shows how much of the substance the material can hold (on the y-axis) at different levels of humidity or temperature (on the x-axis). So, you can see how much water the sponge can hold in different levels of humidity, or at different temperatures.

Scientists use sorption isotherms to understand how materials interact with different substances, like water, in different conditions. They can use this information to design better materials for different purposes, like building structures that can withstand different weather conditions, or creating packaging materials that keep food fresh for longer.