A few years ago I saw this ultralight weight hydrophobic material and I have been trying to discover it's identity. I doubt it was aerogel since it was brought in by a high school student, but I cant say for sure.
It was a transparent whitish material that was very light weight but absorbed ridiculous amounts of water, expanding as it absorbed the water. They were in small pellets, approximately 2mm or smaller randomly shaped. When water is poured on it each individual absorbed large amounts of water and expanded, and each pellet became somewhat gel like (in the sense that each individual pellet was kind of squishy). Unless obscene amounts of liquid was added all it took was a quick shake to more or less absorb every drop of water. Even when squished the material generally didn't start releasing the liquid. If you ended add enough water that the material couldn't absorb anymore, it would float on the water. If left out for a few days the water would evaporate, the material would shrink, and the dry material was somewhat squishy (less so than when wet).
If it's off topic for me to ask something like this then how could I go about identifying this with a list of physical properties.