A team of scientists has invented a new, reusable polymer they say is capable of removing pollutants from water within “seconds”.
The researchers, from Cornell University in the United States, have used cyclodextrin, the same material found in air fresheners, to develop a technique that they say could “revolutionise” the water purification industry.
Led by Will Dichtel, Associate Professor of Chemistry and Chemical Biology at the University, the group has invented a porous form of cyclodextrin that has displayed uptake of pollutants through adsorption at rates vastly superior to traditional activated carbon – 200 times greater in some cases.
Activated carbons have the advantage of larger surface area than previous polymers made from cyclodextrin – “more sites for pollutants to stick to,” Dichtel said – but they don’t bind pollutants as strongly as cyclodextrin.
“What we did is make the first high-surface-area material made of cyclodextrin,” Dichtel said, “combining some of the advantages of the activated carbon with the inherent advantages of the cyclodextrin. When you combine the best features of those two materials, you get a material that’s even better than either class.
“These materials will remove pollutants in seconds, as the water flows by,” he said, “so there’s a potential for really low-energy, flow-through water purification, which is a big deal.”
What’s more, says Dichtel, the cyclodextrin-containing polymer features easier, cheaper regeneration, so it can be reused many times with no observed loss in performance.
Recyclability is another advantage of the cyclodextrin polymer, Dichtel added. Whereas activated carbon filters must undergo intense heat-treating for regeneration, cyclodextrin filters could be washed at room temperature with methanol or ethanol. And a drop-off in performance following regeneration wasn’t observed, Dichtel said.
Dichtel is excited about the potential his group’s results show in terms of the water-purification industry.
“There are a lot of things going for it,” he said. “There are still some unknowns, but everything looks pretty promising.”
The results of approximately 18 months of work were published recently in the journal, ‘Nature’.