What is Porosity?

Some people have problems with measuring the porosity, especially for nanomaterials researchers.

Now, researchers usually adopt the famous static volumetric principle. It uses nitrogen, etc. as an adsorbate and under certain pressure, lets the nitrogen be adsorbed by nanomaterials, then calculates the nitrogen amount and will know the porosity data like pore size, pore volume, pore size distributions and so on.

I find it fascinating that a rock can float because of its porosity. Pumice, a type of volcanic rock, is so porous that it floats.

I saw this demonstrated when my friend brought back some pumice from Hawaii. He learned from a volcanic rock collector that pumice is full of hot gases when it forms. The gas bubbles remain as the lava cools, so pumice is full of air pockets.

These multiple pockets of air make pumice less dense and lighter than an equal volume of water. This high porosity makes it able to float.

When planning my garden, I had an analyst examine my soil. I wanted to make sure that the soil porosity would suit the type of things I wanted to plant.

He told me that even though I had lots of clay in my soil, it had high porosity. I asked him how this could be, because clay is so sticky and it seems like the particles would be jammed up against each other.

The analyst said that the porosity of soil is a ratio of pore space volume to total volume. Since clay has a lot of small pore spaces, it has high porosity.

@kylee07drg - Yes, bread's porosity makes for some yummy food combinations. However, it can cause absolute mush.

I learned this when I started packing my husband's lunch. I personally never eat mayonnaise on my sandwiches, but he likes it.

I made his sandwich the night before with plenty of mayo. When he tried to eat it the next day, he said it was disgustingly squishy, and everything squirted out of the bread when he took a bite.

I have since learned to either make his sandwiches the morning of the day he will eat them or slip a packet of mayo in his lunch bag. The separate packet is best, because even a few hours of soaking in mayo can make the bread unappetizing.

I am thankful for the porosity of bread. I love bread soaked with gravy, syrup, butter, or jelly.

You can see the porosity of bread in action when you place a few pats of butter on a slice and stick it in the oven. The butter melts and covers the whole surface of the bread, but it also seeps into its pores, creating a wonderful flavor throughout the slice.

I love the way that jelly softens a piece of toast. I don't leave it on there too long, because it will get too soft to handle, but just a couple of minutes on a warm piece makes the perfect texture.