We completed the Ring Polymer Lab and Power Point from Nano-links: http://www.nano-link.org/component/docman/cat_view/2-nanotechnology-curriculum/14-nano-link-modules/16-cross-linked-polymers
This lab also uses a form of Sodium Polyacrylate that is in diapers. We reviewed vocabulary with pictures for the terms:mer, monomer, polymer and degree of polymerization. We also discussed attractive forces between atoms and the interactions in water molecules that are ring polymers and can capture and hold a thin film of water and absorb large amounts of water for a small amount of ring polymer. The students could not believe how much weight the material would gain after the water they added was absorbed. We watched this and added salt too to reverse the process.
We also tried other liquids to see if they would absorb too, like rubbing alcohol, vinegar and a salt solution.
Great Resources with lessons and free materials on Nanotechnology in the Classroom
https://nanohub.org/resources/animations
http://www.nnin.org/education-training/k-12-teachers
http://nano.gov/education-training/teacher-resources
http://www.nanooze.org/ free magazine hard copies or online for kids