What's Inside a Diaper? Project

We have some left over, fairly low quality [i.e. leaky], WalMart-brand diapers (White Cloud and Parent's Choice) in a size too small.  So I figured that it is time for...a Science Experiment!

I chose one diaper, and prepared the specimen for dissection:

After some preliminary incisions to remove some connective tissue, I was able to peel back the outer layer, revealing the inner guts of the diaper:

This flaky, dusty, papery, almost cotton-like material was laced with little beads:

Upon addition of water, I noticed two phases of absorption.  First there was a rapid, although weak absorption by the papery stuff.  This was followed by the second, stronger, slower absorption phase when the beads started taking up the water.

This two-stage method is fairly clever, and efficient in vivo.  The first step rapidly pulls the, well, "moisture" away from the, erhm, "source," decreasing the likelihood of instant leaks, while the second phase stores the "moisture" well for a longer period of time, thus allowing the source's "handlers" to sleep a little bit longer.

But just how much moisture can these things hold?

The dry weight of the absorbent part of the diaper is around 20 grams.  I added water until it just stopped absorbing:

The added weight of the absorbed water was around 600 grams (and the absorbed volume was similarly around 600 ml).  So, the diaper can hold around 30 times its weight in fluid.  (And these are the cheap diapers!)  I was pretty impressed.
Here are the beads at near-full absorbency:

We still have a bunch of these diapers left, so if there are any further experiments you'd like to see, please let me know in the comments.

And now you know What's Inside a Diaper.  Aside from the obvious, that is.