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Make Glowing Slime
In this science experiment, kids explore chemical reactions, polymers and fluorescence while making awesome glowing slime!
The school glue we used in our solution contains a polymer called polyvinyl acetate. When we add Borax to the glue, the polymer chains in the glue are linked together creating something that looks like a net or spider web. This is called a “cross-linked polymer” which is stretchy – like slime!
Your creation glows under a black light because it contains phosphors extracted from the highlighter ink. Phosphors are chemicals that absorb then release energy from light. The phosphors in this experiment are “fluorescent,” meaning they release their light quickly and don’t retain a glow over time. When phosphors release the light slowly and create a lingering glow, like with glow paint or glow stars, this is called “phosphorescence.”
Using a black light is a great way to demonstrate phosphors. A black light emits ultraviolet radiation type A, or “UVA” radiation. This is similar to the ultraviolet radiation type B (“UVB”) that comes from the sun, but is not harmful. (When you look at a black light, you will see a purplish glow, but this isn’t the UVA radiation. The UVA radiation is there, but it is invisible.) When UVA radiation shines on things containing phosphors, the phosphors absorb the invisible light and turn it into visible light – that’s the glow you see in the slime!
Safety Notes
Borax is a laundry booster, and in general is a reasonably safe household chemical. However, you should not allow children to have extended direct contact with Borax or a Borax solution as extreme prolonged exposure can cause a chemical burn. It also can be harmful if ingested.
Materials
- Water - 1 cup per class
- Borax - 1 teaspoon per class
- Fluorescent water* - 1 cup per class
- Clear washable school glue - 1 cup per class
- Bowls - 2 per class
- Disposable spoons - 2 per class
- Black light bulb (or similar) - 1 per class
- To Make 4 Cups of Flourescent Water:
- Yellow highlighter marker - 1 total
- Blue or green highlighter marker - 1 total
- Water - 4 cup total
Instructions
To make the fluorescent water:
Carefully open the end of each highlighter, pull out the soft ink insert and cut it open. Place both in 4 cups of water and allow to soak for about 10 minutes. Tip: If you make this in a recycled 2 liter bottle, you’ll be able to easily pour out what you need and store what you don’t need for later.
To make the glowing slime:
Pour 1 cup of plain water into a bowl. Add 1 tsp of Borax and stir until dissolved.
In a second bowl, pour in 1 cup of fluorescent water.
Add 1 cup clear glue to the fluorescent water and stir.
Combine the water and Borax solution with the watery fluorescent glue solution and stir. Voila – glowing slime! Tip: if the glue is still sticky in places, make sure it has all come in contact with the Borax solution; this is what turns the glue solution into a slimy solid.
To make your slime glow, head into a dark room (or make your own bat cave under a table with blankets!) and shine a black light on the slime.
