Science / Medicine : New Membranes Separate Gases

UCLA chemists reported last week that they had developed a new family of membranes that are highly effective at separating gases. Richard B. Kaner and his colleagues reported in the journal Science that the membranes could be used to produce pure oxygen or nitrogen, for example, much more cheaply than existing methods, which rely on cooling air to very low temperatures.

Nitrogen isolated with the membranes could be used, for example, to prevent stored fruit from rotting and to protect air-sensitive materials, such as semiconductor chips, during shipment. It might even be possible to use the membranes to remove pollutants from automobile and industrial exhausts.

The UCLA membranes differ from other so-called “semipermeable membranes” in that they are made from an organic material, called polyaniline, that conducts electricity. This polymer can be “doped” with charged atoms to produce precise changes in its selectivity, Kaner said.