Screening pollutants

Research sponsored by the National Science Foundation and DARPA Research Center for Micro/Nano-Electromechanical Transducers has garnered some breakthroughs in what could be the next era of pollution reduction.

Graphene membranes, which are known to be selectively porous, exhibit the capability to screen out pollutants by separating inert carbon dioxide molecules from larger, more potentially harmful ones, such as nitrogen and sulphur hexaflouride.   The graphene membranes work especially well for gaseous "pollutant" materials because of the semi-permeable nature of graphene membranes.

Illustration by Zhangmin Huang

"The findings are a significant step toward the realization of more energy-efficient membranes for natural gas production and for reducing carbon dioxide emissions from power plant exhaust pipes," reports the University of Colorado at Boulder, where much of the research took place.  "Those characteristics make graphene an ideal material for creating a separation membrane because it is durable and yet doesn’t require a lot of energy to push molecules through it, he said."

Given these findings, may I hypothesize about some other related applications --  Radiation containment?   Automobile exhaust pipes?  Chimney screens?

As with any recent breakthrough, there are some logistical challenges to be overcome before the applications can be widely applied.    For example, "creating large enough sheets of graphene to perform separations on an industrial scale, and developing a process for producing precisely defined nanopores of the required sizes are areas that need further development. The CU-Boulder experiments were done on a relatively small scale."