Scalable membrane could filter greenhouse gases

A team at UCLA developed the technique, “thin-film lift-off” (T-FLO), which results in a membrane that is more scalable and energy efficient than those used currently in industrial processes.

Brian McVerry, co-author of the study describing the process said: “Researchers around the world have demonstrated many new exciting materials that can separate salts, gases and organic materials more effectively than is done industrially.

“However, these materials are often made in relatively thick films that perform the separations too slowly or in small samples that are difficult to scale industrially. We have demonstrated a platform that we believe will enable researchers to use their new materials in a large, thin, asymmetric membrane configuration, testable in real-world applications.”

A filtration membrane’s core purpose is to allow desired products, such as water, to pass through while separating out waste and toxic molecules. Membrane filtration is used for the filtration of seawater, treatment of wastewater and conducting kidney dialysis.

Normally, to make membranes requires the formation of two layers: the “active layer” that blocks molecules based on size; and the “support” layer that stabilises the membrane and allows it to work under the high pressures created by the filtration.

The T-FLO technique uses epoxy to manufacture the support layer. Unlike other membranes where both layers must be produced together, this allows the active layer to be created first using high temperatures and damaging chemicals before the support layer is made, preventing damage to the support layer.

So far in experiments the T-FLO technique has been able to desalinate water and separate greenhouse gases. In the future, membranes that use the T-FLO may also be able to remove CO₂ from industrial emissions and use it for fuel.

UCLA’S study has been published in Nano Letters.

Lydia Wilson