Cheap new plastic material great at adsorbing CO2

Researchers in California have produced a cheap plastic capable of removing large amounts of CO2 from the air. Down the road, the new material could enable the development of large-scale batteries and even form the basis of "artificial trees" that lower atmospheric concentrations of CO2 in an effort to stave off catastrophic climate change.

These long-term goals attracted the researchers, led by George Olah, who won the 1994 Nobel Prize in chemistry. The team has been working the development of making cheap, iron-based batteries that can store excess power generated by renewable energy sources and feed it into the electrical grid during times of peak demand. To function, the iron batteries grab oxygen from the air. But if even tiny amounts of CO2 get into the reaction, it kills the battery.

In recent years, researchers have come up with good CO2 absorbers made from porous solids called zeolites and metal organic frameworks. They are, however, expensive so Olah and his colleagues turned to polyethylenimine (PEI), a cheap polymer that is a decent CO2 absorber, and boosted its adsorption capabilities by layering it on top of a porous base.

In humid air – the kind present in most ambient conditions – each gram of the material sopped up an average of 1.72 nanomoles of CO2. That's well above the 1.44 nanomoles per gram absorbed by a recent rival made from aminosilica and among the highest levels of CO2 absorption from air ever tested, the team reported last month in the Journal of the American Chemical Society.