Aerogel Is Made From Waste Plastic Bottles

Researchers at the National University of Singapore call it an "ultralight supermaterial."

Aerogels are the Porsches of insulations, incredibly efficient and incredibly expensive; according to NASA (which uses a lot of the stuff), it costs about a buck per cubic centimetre. (Commercially available aerogels are cheaper but still expensive.) So the exciting news out of the University of Singapore, via New Atlas, was that they had developed a new aerogel made out of PET water bottles, which we obviously have a lot of. According to their press release with the grabby title, NUS researchers turn plastic bottle waste into ultralight supermaterial with wide-ranging applications:

“Plastic bottle waste is one of the most common types of plastic waste and has detrimental effects on the environment. Our team has developed a simple, cost-effective and green method to convert plastic bottle waste into PET aerogels for many exciting uses. One plastic bottle can be recycled to produce an A4-sized PET aerogel sheet. The fabrication technology is also easily scalable for mass production. In this way, we can help cut down the harmful environmental damage caused by plastic waste,” said Assoc Prof Duong.

Alas, in the abstract to the published study, the PET aerogel has a thermal conductivity of 0.037 W/m.K. A look at Greenspec shows that fiberglass batts have a thermal conductivity of 0.035 (lower is better). Real silica aerogels have a thermal conductivity of 0.014 W/m.K, almost three times as efficient. For that matter, insulation made from spinning PET bottles into fibres and making batt insulation came out at 0.0355 W/m.k, or slightly lower than the aerogel.

© National University of Singapore

Back at the University of Singapore, they call their aerogel an "ultralight supermaterial with wide-ranging applications." They mix it with fire retardants and say it will resist high temperatures, and build it into fireproof clothing. They can make filters and sponges out of it. Lots of great uses for waste PET bottles.

Because they call it an aerogel, which sounds so fancy and high-tech, I suspect that a lot of websites will pick this up, along with the headline "ultralight supermaterial". But given that it has the thermal conductivity of fiberglass, I think that is a bit of an overstatement.