Discovering Slime!

The ACE Programme recently explored some very cool science, - SLIME!

What is "slime" anyway? Well, if you look it up in the dictionary, you'll find several definitions. But for classroom purposes, it's a gooey polymer consisting of over 97 percent water – plus polyvinyl alcohol, which easily dissolves in water, causing its units to link and form "chains." This gives the solution a thick, syrupy appearance.

When borax (sodium tetraborate) is added to the polyvinyl alcohol solution, the chains of polyvinyl alcohol cross-link to form a viscous, elastic gel. Since the cross-linking is weak, the chains continually form and break under the weight of the gel or with handling. The mixture of polyvinyl alcohol, borax and water results in a rubbery, slimy colloid, which feels cool because it absorbs the heat from your hand.

When you add a substance like shaving foam which contains loads of air, you get a slime that not only is able to expand more, but also smells yum!

This is the recipe we used.  However, there are many, many more on the internet.  We found it is best to just play around as see what you can come up with.