Slime Science

To prepare a slime you need:

25g – Glue

2 tablespoon – Water

Some drop – Food colour (Optional)

1/2 teaspoon – Baking soda

1 tablespoon – Contact lens solution

Method:

1. Add glue in a bowl.
2. Then add water and food colour mix it properly.
3. Add baking soda and contact lens (Activator) solution and mix it until it become thick.

Non-Newtonian fluids

Newton described how ‘normal’ liquids or fluids behave, and he observed that they have a constant viscosity (flow). This means that their flow behaviour or viscosity only changes with changes in temperature or pressure. For example, water freezes and turns into a solid at 0˚C and turns into a gas at 100˚C. Within this temperature range, water behaves like a ‘normal’ liquid with constant viscosity. Typically, liquids take on the shape of the container they are poured into. We call these ‘normal liquids’ Newtonian fluids. But some fluids don’t follow this rule. We call these non-Newtonian fluids.

Real life example:

A ketchup which will not come out of the bottle until you stress it by shaking. This helps to control the flow of the ketchup.

Paint

Shampoo

And many more

The behaviour of non-Newtonian fluids has important implications:

• If a house is built on certain types of clays and an earthquake puts stress on this material through the sudden movement, the apparently solid clay can turn into a runny liquid. This is called liquefaction. Liquefaction was particularly destructive in the Canterbury earthquakes of 2010 and 2011.
• Body armour that behaves like a liquid so that you can move easily but turns into a solid on impact from stress could be useful for police or the military.

Polymer

Polymer is a molecule made up of many monomer “poly” meaning “many” (in Greek) and “mer” meaning “unit”.

For example:

Pearls in a necklace

Pearl- Monomer

Necklace- Polymer

Some polymers bend and stretch, like rubber and polyester. Others are hard and tough, like epoxies and glass.

What happing in the slime reaction

Glue is made up of long chain of polymer which is PVA (Polyvinyl acetate). When we add our activator which is baking soda and contact lens solution. It tangle the chai of PVA.

Troubleshoot:

• If your slime is not getting slimy try adding more activator (baking soda and contact lens solution)
• Check the ingredient of contact lens solution it should contain boric acid or borax (if not, try another recipe or use borax powder or liquid starch for activator)
• Store your slime in an air tight container
• Do not dispose it in a sink

Reference:

• https://www.sciencelearn.org.nz/resources/1502-non-newtonian-fluids

Video:

https://youtube.com/watch?v=sk1V_jfwTkY