In a groundbreaking development, scientists in Australia have engineered ultra-thin filters capable of swiftly and efficiently separating valuable chemicals from liquid mixtures. This innovation is poised to transform the production of medicines, dyes, and other products, potentially reducing industrial waste, conserving energy, and lowering costs.
The research team, led by Yuxi Ma, a PhD scholar at RMIT University, and Professor Weiwei Lei, has created hybrid filters that merge super-thin layers of boron nitride with durable synthetic fibers known as aramid. This combination results in a flexible yet robust filter that remains stable even under high pressure.
Innovative Material Design
Boron nitride, typically water-repellent, posed a challenge in combining with other materials. “We altered its surface to attract water instead,” Ma explained. “This change allowed us to form a stable mix with the fibers, resulting in a much stronger composite filter.”
The implications of this innovation are significant for cleaner, more efficient chemical manufacturing and recycling. “Many industrial processes rely on solvents to produce or purify products, but separating and reusing these solvents can be slow and energy-intensive,” Ma noted. “Our filters allow solvents to pass swiftly while retaining larger molecules, offering a faster and more sustainable method to recover useful chemicals.”
Laboratory Success and Future Prospects
In laboratory tests, the filters demonstrated effectiveness with common solvents such as ethanol, methanol, and acetone. They maintained stability under pressures up to 10 bar—approximately ten times the pressure in a car tire—and performed consistently during 24 hours of continuous use.
By adjusting the thickness of the active layer, researchers could control the filter’s selectivity. A thickness of about 1 micrometer provided the optimal balance between fast flow and strong blocking performance, filtering out up to 96% of larger dye molecules.
“Because the layers bond through natural hydrogen interactions, we can fine-tune the structure without needing complex chemical treatments,” Ma said. “This makes the process easier to scale and more adaptable for different solvents or applications.”
Challenges and Industrial Applications
While the filters performed well in mild conditions, challenges remain in more extreme environments. Very alkaline conditions reduced performance, and some harsh solvents caused gradual swelling. The team is now refining the chemistry to enhance durability and testing larger sheets under real-world conditions.
Professor Lei emphasized the potential industrial applications of this research. “We’ve shown it’s possible to create an ultra-thin, pressure-resistant filter using materials that are lightweight and easy to handle,” he said. “Our next goal is to work with industry partners to scale up production and test the technology in chemical recycling and purification systems.”
The potential applications of these filters are vast, ranging from pharmaceutical and dye production to wastewater treatment. “Improving filtration efficiency isn’t just about saving time—it’s about cutting waste and enabling circular manufacturing,” Lei added. “With further development, we see strong potential for these filters to help industries transition to more sustainable processes.”
Collaborative Research and Future Steps
This research, titled ‘ANF/BN thin-film composite membranes for efficient organic solvent nanofiltration,’ is published in the Journal of Membrane Science. It represents a collaborative effort between RMIT University’s School of Science and School of Engineering and a researcher from Deakin University in Geelong.
Organisations interested in partnering with RMIT researchers are encouraged to reach out to explore potential collaborations. As the team continues to refine and expand the application of these filters, the future of chemical production and recycling looks increasingly sustainable.
Contact for collaboration: [email protected]
Images and further details are available through RMIT University’s communications channels, with Professor Weiwei Lei and Dr. Yuxi Ma leading the charge in this innovative field.
