Chitin has a number of physical and chemical properties that make it advantageous as a sorbent backbone for the extraction of uranium from seawater. One which makes chitin particularly unique when compared to most other functional polymers is the presence of an N-acetyl group which can be easily converted to a reactive amine. We have shown that materials prepared by extracting chitin from biomass using the ionic liquid 1-ethyl-3-methylimidazolium acetate, in which chitin is unusually soluble, can be functionalized on the surface by exposure to treatment baths in which the bulk material is insoluble. While functionalization of synthetic polymers by methods such as copolymerization or synthetic modification of the monomer effectively results in a completely different polymer, the surface-specific functionalization of chitin results in a measurable change in metal affinity with no measurable changes to bulk physical properties such as composition and strength. Furthermore, the nucleophilic amine in chitin can be easily tethered to almost any functional group with almost any linker, giving chitin-based materials extreme potential for variability.<br/>We are currently researching new surface treatments to improve the economics and performance of chitin-based sorbents for uranium from seawater. By varying the extractant functional group, new metals can be targeted for additional value or added functionality to the polymer. The linker group which tethers the extractant can also be modified to improve performance. Examples of the synthesis, characterization, and testing of such functional materials will be presented here.

Nanofiber chitin mats for coextraction of value added metals from seawater: Improving the economics of uranium recovery

249th National Meeting (2015)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.