Monash University engineers have developed a new filtering material that could make plastic recycling cheaper, easier and more environmentally friendly by helping recover and reuse valuable chemicals during the recycling process.
The breakthrough nanocomposite membrane formulation was developed in collaboration with CSIRO and The University of Texas. Published in Chemical Engineering Journal, the study focuses on improving glycolysis, a chemical recycling process in which PET plastics are broken down using a liquid chemical called ethylene glycol. PET plastic is commonly used in drink bottles, food packaging and clothing textiles.
During glycolysis, PET plastic is broken down into valuable chemical building blocks, but the process is costly because recovering and reusing ethylene glycol from the reaction mixture is challenging.
Rather than relying on energy-intensive methods, the team designed highly selective nanocomposite membranes that act like filters, separating water from ethylene glycol.
This allows ethylene glycol to be recovered at high purity and reused in the depolymerisation process, helping reduce chemical use and improve the cost-effectiveness of chemical recycling.
Lead author Dr Hamidreza Mahdavi, a Research Fellow at the Monash Department of Materials Science and Engineering, said the work addresses a major gap in current recycling systems.
"Plastic waste still contains valuable building blocks. Our work shows that membrane technology can help recover these building blocks more efficiently from PET recycling streams, so they can be reused rather than wasted," Dr Mahdavi said.
"Instead of only recovering energy from end-of-life plastics, we are trying to recover the building blocks needed to make new materials. This is an important step toward a more circular approach to plastic recycling."
The research demonstrates that this membrane-based separation approach can operate under conditions relevant to real-world recycling processes, offering a practical pathway to scale.
The technology could be applied across a wide range of PET waste streams, including bottles, packaging, trays and synthetic textiles.
In the long term, the innovation could help reduce plastic waste, lower emissions, improve the economics of recycling, and support the transition to a circular economy.
This latest work builds on a broader research program, following an earlier review of advanced technologies that identified membrane solutions as promising, and a subsequent perspective paper on integrating them into PET recycling.
Conducted under the CSIRO-Monash collaboration project, and in collaboration with The University of Texas at Austin, the new experimental study is the next step, demonstrating membrane-based ethylene glycol recovery in practice, with further research already planned to advance the technology.
Read the research paper: https://doi.org/10.1016/j.cej.2026.176529
