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Taking Radioactive Contaminants From Water With Shells
RedEaredSlider writes "Crab shells may soon be used to take radioactive contaminants out of water. Joel Pawlak, an associate professor of forest biomaterials at North Carolina State University, has developed a material similar to foam rubber that absorbs water and attaches to molecules dissolved in it, leaving pure and potable water behind. The material is a combination of hemicellulose and chitosan. The first comes from wood and is extracted by the ton in the paper-making process. Chitosan is extracted from ordinary crustacean shells — primarily crab, shrimp and lobster — by treatment with hydrochloric acid and then sodium hydroxide."
... are planning a march on Washington to protest.
Chitosan is extracted from ordinary crustacean shells — primarily crab, shrimp and lobster — by treatment with hydrochloric acid and then sodium hydroxide
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Hmmm . . . that is one treatment that I will try avoid, if possible . . .
Schroedinger's Brexit: The UK is both in and out of the EU at the same time!
Almost sounds like an acid-base extraction. Is it an alkaloid?
We've known for years that three shells is all you need to remove common contaminants. Now, if only someone would post instructions...
Required reading for internet skeptics
A polysaccharide.
Mostly harmless.
So it is, but there is still that dangling amine group on the monomer which would be susceptible to acid base extraction if you'd find a suitable non polar solvent.
It's a polysaccharide, in which some of the saccharides are D-glucosamine, which is basic.
rm -rf radioactivity perhaps? Seriously, if you don't know the basics, do not post on slashdot!
Eat lobster and save the world!
I don't think that because glucosamine as a dietary supplement is pretty expensive, it follows that that glucosamine as an industrial reagent will be as well. The prices of medicines and supplements rarely are cost of production and distribution plus reasonable markup.
Apocalypse Cancelled, Sorry, No Ticket Refunds
Sounds like they're combining the properties of both a cationic and anionic polymer with the idea of maximizing the surface area on which the adhesion occurs (similar to activated carbon).
Basically, in layman's terms... most things that dissolve in water form ions (either positively or negatively charged), which can be removed by their electrostatic adhesion to oppositely-charged ions. According to TFA, this polymer foam has both positively and negatively charged ions at its surface for the dissolved ions to adhere to (perhaps someone with more knowledge of organic chemistry could tell me if this is fairly unique? I've never heard of a polymer which was both cationic and anionic). Since the ions actually cling to its surface, the surface area should be maximized (the principle behind an activated carbon filter), which in this case they're doing by making it into a foam.