Science:
A new kind of plastic that can remove large amounts of CO
2 from the air has been produced by a research team
led by George Olah of the University of Southern California in
Los Angeles. Olah and his team needed a CO
2 absorber for iron-based batteries they were
working on; they tried using polyethylenimine (PEI), an
inexpensive CO
2 absorbing polymer. PEI grabs CO
2 only on its surface, so to increase its surface
area, Olah dissolved the polymer in a methanol solvent and
spread it atop a batch of fumed silica, an industrially
produced porous solid made from microscopic droplets of glass
fused together. When the solvent evaporated, it left solid PEI
with a high surface area. When the team tested the new
material's ability to absorb CO
2, they found that in humid air each gram of the
material absorbed an average of 1.72 nanomoles of CO
2. That's one of the highest levels of CO
2 absorption from air ever tested. The material also
sheds CO
2 when it's heated to 85 °C, whereas other
solid CO
2 absorbers have to be heated to over 800 °C to
shed CO
2. The new polymer could be used to scrub CO
2 from the air, although it couldn't be used in
industrial smokestacks or automobile tailpipes without
additional tinkering to make it more heat-resistant.
