Bindeez and Aquabeads are toys consisting of little brightly-coloured spheres that are stacked together to make sculptures, models and patterns which are fixed together by spraying them with plain water.
How do they work? I mean, it would seem obvious that they’re coated with, or composed of, some kind of glue, but if that’s the case, how are they prevented from sticking together in storage in the presence of atmospheric moisture?
It’s definitely only water that they’re sprayed with - the adverts explicitly say so.
On their Bindeez Tips web page, it says that you can make 3D designs by making 2D designs, drying them, and then re-wetting them and sticking them together. And that if you get random wet beads sticking to things, dry them and then remove them.
So even if your beads do stick together in storage, all you have to do is dry them thoroughly, and then use them.
My guess as to the physics involved is that it probably isn’t some kind of “glue”, or else you wouldn’t be able to dry them and re-wet them and use them. My guess is that it’s some kind of water-absorbing polymer, similar to those “water crystals” you can put in potted plants.
I’m interpreting that to mean that they don’t fall apart on their own when they dry out, because otherwise your 3D creations would collapse, but that you can break them apart deliberately.
My guess would be that the water-absorbing polymer, whatever it is, probably has a certain amount of water molecules that it can absorb before the surface actually starts to “feel” sticky, and to adhere to other substances. So it’s just a question of degree–once the surface gets to a certain degree of wetness, then the beads start sticking to things.
And, short of baking your creations in an oven for a longer period of time than just using a hair dryer on them for a minute, you’re never going to get all the water molecules off the surface of the beads, hence your creations remain just a tad sticky at the molecular level, and they don’t fall apart when dry.
I’m going to go down to Hobby Lobby and get some.
To experiment with.
Yes, that’s it. For an experiment. It’s not “fun”–this is Science.
Update: I never did succeed in finding some at Hobby Lobby, but today this news item appeared, and I thought for future reference, if someone’s ever searching in the archives under “bindeez”, it should probably be included.
