Clean water is essential, yet in certain parts of the world, it’s very difficult to obtain. Unfortunately, our limited water resources are being polluted by chemicals from industrial plants, pesticides, pharmaceuticals, and more.
Adsorbant materials composed of carbon are often used to remove many of these organic pollutants. However, they act slowly, typically miss hydrophilic micropollutants, and can be difficult to reuse.
Scientists working on developing inexpensive materials that can purify water quickly have been working with an insoluble polymer called β-cyclodextrin (β-CD)—a big loop of linked sugar molecules. Recently, they’ve discovered a way to cross-link β-CD using aromatic groups forming a porous, cross-linked complex. The porous, cross-linked β-CD has an increased surface area that significantly speeds the removal of pollutants.
Cyclodextrin is a well known material that basically traps materials in its interior core. It’s actually one of the main ingredients in Febreze because it can trap small odor causing materials and “deactivate” it which is why febreze works for odor elimination (as opposed to perfume based products which just cover it).
The unique science here is the cross-linking effect which solves some of the issues with cyclodextrin by making it bigger, less water soluble, bigger surface area, etc. It however still doesn’t solve some of the other issues with cyclodextrin, such as its general preference for hydrophilic materials (which is ok if its designed for water based systems), loading rates (one molecule of cyclodextrin can’t hold much), size limitations (has to fit inside the core which means big molecules are out, and etc other issues (there’s a reason cyclodextrin is not being used everywhere already).
Cool results but would like to see how it truly performs in a real use scenario with many more varied and complex pollutants. For example – antibacterial/parasite effects is in general more important than trace amounts of BPA for the regions/use they’re targeting. Most of the people who need clean water are much more worried about dysentery than they are about trace BPA…
If it’s cheaper than carbon, could this potentially something that could scale to an affordable whole-house water filter?