University of Queensland researchers have developed membrane technology that could improve the efficiency of energy-intensive industrial processes by allowing molecules to move faster without compromising separation accuracy.
The technology could have applications in chemical purification, resource recovery, sustainable fuel production and other processes where separating specific molecules is essential.
Chemical engineering researchers developed the system by focusing on the tiny channels inside membranes, which are less than one nanometre wide – approximately 100,000 times thinner than a human hair.
These channels control how molecules move through a membrane but can also create frictional and adhesive barriers that slow transport. Improving the speed of molecular movement without reducing separation precision has been a longstanding challenge for membrane science.
Professor Xiwang Zhang, director of the UQ Dow Centre for Sustainable Engineering Innovation and the ARC Centre of Excellence for Green Electrochemical Transformation of Carbon Dioxide, said the breakthrough addressed this trade-off.
“Allowing molecules to move faster while maintaining exceptional separation precision potentially reduces energy consumption in these industrial processes” he said.
Professor Zhang said industries needed membranes capable of processing large volumes of material quickly while allowing only the desired molecules to pass through.
“But the faster molecules move through a membrane, the harder it becomes to separate them precisely.
“Overcoming this trade-off has been one of the biggest challenges in membrane science.”
Rather than changing the size or chemistry of the channels, the researchers introduced self-rotating ammonium ions to create a more dynamic transport environment.
The approach allows molecules to move more efficiently through the channels, which the researchers describe as molecular highways. The movement of the ions helps improve energy transfer and reduces barriers to molecular transport.
Professor Zhang compared the self-rotating molecules to a turnstile that regulates molecular traffic while allowing it to move quickly.
“Essentially we have upgraded the highways so that we get the best of both worlds: speed and selectivity.”
Experiments involving the separation of ethanol and water demonstrated a tenfold improvement in separation accuracy compared with a standard filtration membrane.
“Our new membrane increased water transport by approximately 44 per cent, and reduced ethanol by 90 per cent,” Professor Zhang said.
The findings could provide a pathway towards more energy-efficient separation processes, potentially reducing the resources required to purify materials and recover valuable substances.
The researchers’ next step is to translate the technology into practical applications. Potential areas include industrial separations, resource recovery, carbon dioxide utilisation and environmental protection.
The work highlights the potential for membrane engineering to improve industrial processing by addressing limitations in how efficiently materials can be separated.
Further development will be required to establish how the technology performs in practical applications and across different industrial processes.