Howdy friends
I’m interested in the super-absorbent polymer that’s in diapers, sodium polyacrylate. The more I learn about this chemical, the more I appreciate how it, and its agricultural cousin potassium polyacrylate, are some of the most widespread polymers in the trash stream (or whatever you call it when you plow tons of loose polymer directly into agricultural soil).
So this polymer is bonkers – it can soak up water better than anything else we have – adsorbing between 300x-900x its mass in water. That means 1.1g of polymer can adsorb 1L of (distilled) water, or 330g of ion-filled urban runoff!!!
One thing that’s really interesting to me is the work that’s been done in getting the polymer to grab on to heavy metals. If you’re good at chemistry, you can engineer some interesting affinity for heavy metals, where the polymer soaks up polluted water with heavy metals, the water evaporates, but the heavy metals stay behind, and then you can get them out of the polymer with a gentle acid bath. (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9572998/, Superabsorbent Hydrogels for Heavy Metal Removal | IntechOpen, and many other papers on the topic)
Now I want to play around with making my own versions of this molecule, but I’m something of a chemistry idiot. I’m trying to get a better understanding of the forces at play in the molecules, to help me make a plan for building my own molecules designed to treat urban runoff. Would anyone with some experience in polymers be up for spending an hour tutoring me in the ways of the diaper?