(Photo: Aerogel made from recycled plastic bottles. Credit: National University of Singapore)
National University of Singapore scientists report that they have figured out a way to successfully convert plastic bottle waste into aerogels for the first time. The engineers say this new lightweight material has a range of potential applications including environmental remediation, and firefighting.
The NUS team’s fabrication technology, led by mechanical engineering faculty Hai Minh Duong and Nhan Phan-Thien, took two years to develop. Made from polyethylene terephthalate (PET), the aerogel is ultralight and porous with the advantage of being soft, flexible, and durable, according to the researchers.
“With our new method, one plastic bottle can be recycled to produce an A4-sized PET aerogel sheet,” said Duong, an associate professor in the Department of Mechanical Engineering at NUS Faculty of Engineering. “The technology is also easily scalable for mass production.”
One advantage to the new material is its ability to absorb oil as much as to seven times more effectively than other commercially available products, the researchers say. And when the team coated their aerogel with fire retardant chemicals, the material withstood temperatures as high as 620°C (1148°F).
“By adopting our PET aerogels that are coated with fire retardants as a lining material, firefighter coats can be made much lighter, safer, and cheaper,” Nhan said. Fitting the aerogel into masks could mean protecting wearers from carbon dioxide and dust particles.
The team published their findings in the scientific journal Colloids and Surfaces A, and filed a patent for the technology.
This scientific development comes at a time when large corporations are re-examining plastic bottle waste and recycling. Cargill invested $10 million in a new bottling line that the company says will increase capacity, reduce packaging material waste, and utilize recyclable PET plastic. Coca-Cola said they plan to collect and recycle the equivalent of every bottle or can they sell globally by 2030.
PepsiCo signed a multi-year supply agreement last month with sustainable plastic manufacturer Loop Industries to expand their use of 100% recycled PET plastic in packaging. PepsiCo also joined the NaturALL Bottle Alliance started by Danone, Nestlé Waters, and Origin Materials with the goal of developing packaging from 100% sustainable and renewable resources.