Indestructible Coating - Polyurea
Description: In this video a watermelon is covered with a polymer and survives a drop from a large tower. The polymer is formed when two reactants join to make a flexible and durable polymer known as a polyurea. The chemical reaction is exothermic, releasing heat as the reactants combine. This phenomenon could be used in a unit on chemical reactions, extended structures or chemical engineering. The company Line-X uses this polymer to make bed liners for pickup trucks.
Web Resources: Polyurea - Wikipedia, Line-X
Aerogels - World’s Lightest Solids
Description: Aerogels are a group of synthetic materials that are incredibly light and also amazing insulators. They have numerous applications such as insulators in electronics. Aerogels were used as thermal insulators in the Mars Rover and also act to filter space dust. This phenomenon could be used as an application of chemical engineering or as an example of a thermal insulators.
Web Resource: Aerogel - Wikipedia
Reusable Heat Packs
Description: This phenomenon uses a supersaturated solution of sodium acetate. Clicking the metal disc releases a small number of crystals of sodium acetate which act as nucleation sites for the crystallization of the sodium acetate into a hydrated salt. Energy is released from the crystal lattice. The heating pack can be placed in boiling water and the sodium acetate can be dissolved again. This phenomenon shows how bond energy can be released. It also shows the importance of chemical engineering and could lead to a section where students design a device (or application) of their own.
Web Resource: Chemical Heat Pack - Wikipedia, Snappy Heat - Amazon
Slime
Description: Everyone loves slime...especially elementary students. This phenomenon is a great introduction into chemical reactions. The properties of the reactants can be compared to the properties of the products to show that a chemical reaction has occurred. In high school the chemistry of polymers and cross-linking can be explored through slime.
Web Resource: The Science of Slime - American Chemical Society
