I am glad to find very cheap superabsorbent balls (see image below). However, I found their expansion is not reversible. The wiki entry 'Superabsorbent polymer' also says that the material will 'retain' extremely large amounts of a liquid relative to their own mass. enter image description here enter image description here

Is there any other superabsorbent material whose expansion is reversible? If yes, is it available as tiny balls?


Yes. The ones I have are known commercially as Jelly Marbles or Orbeez. They're sold at gardening stores, home decor, and online. They're used as toys but also as gardening products that absorb excess moisture in wet conditions and supply water in dry conditions. Mine grow up to about 1.5cm from a starting diameter of ~0.1cm. I've been told that some grow up to ~7.5cm; and they're advertised as increasing by 100-300 times in volume at full saturation. The process is reversible (e.g. by putting them in a cup with a wad of paper towels). I use them as a drying agent where powdered $\ce{CaCl2}$ etc. aren't ideal.

Note the actual identity of the polymer in the beads is a trade-secret, so I don't think you'll be able to find that information.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.