Unveiling the Mystery of Crystal Babies

[theow]

Hi there, this is my first ever post in PF.
Have you heard of crystal babies?
They have been very popular among Taiwan students.
And I have googled some information and some people said they consisted of "arcrylate polymers". They also said they are similar to Magic/Crystal Soil.
Would anyone tell me what actually are "arcrylate polymers"?
Any how can the Crystal Babies "divide" and "merge"?
Thanks a lot!

 

[chemisttree]

If these are indeed acrylic-based polymers, then the polymer has been modified with salt groups like sulfonate groups. The polymer is a lightly crosslinked (perhaps 0.1% level) sulfonated acrylic polymer extruded into beads before crosslinking. After drying, the tiny beads occupy much less space and when re-hydrated swell to their original size or larger depending on the ionic strength of the aqueous solution they are placed within. If the water used is tap or distilled, the balls can swell to the point of fracture. This phenomenon of division is seen by some as being similar to giving birth. After they 'divide' they do not 'merge' again... that just wouldn't be right!

Other polymers can do the same thing, by the way. Sulfonated starches have been used in this manner as have sulfonated acrylamides, which are usually the polymers associated with the artificial soil products. Unreacted monomers (both acrylic and acrylamide) are toxic and testing needs to be done on these things to see if the degree of polymerization is complete enough to be called 'safe'. Don't stick them in your mouth! Wash your hands after handling them if you are unsure.