Researchers from the University of Singapore are tacking the global issue of plastic waste by converting plastic bottles into the world’s first PET aerogels.
Although bottles are recyclable, plastic waste is also toxic and non-biodegradable. Despite recent efforts to curb plastic waste, the global consumption of plastic bottles has been rising steadily, and it is expected to exceed half a trillion tons per year by 2021. Such waste often ends up in oceans and landfills, affecting marine life.
Plastic bottles are commonly made from polyethylene terephthalate (PET), and researchers have found a way to convert this into PET aerogels; materials that are soft, flexible, durable and extremely light. They are also good insulators and have a strong absorption capacity.
These properties make them useful for a wide range of applications, such as for heat and sound insulation in buildings, oil spill cleaning and as a lightweight lining for firefighter coats and carbon dioxide absorption masks.
Combating pollution with plastic waste
As well as combating plastic waste, such technology can also benefit people living in countries such as China, where air pollution and carbon emission are major concerns. When coated with an amine group, the PET aerogel’s absorption capacity is comparable to materials used in gas masks, which are costly and bulky.
Study lead associate professor Hai Minh Duong believes that the research can help solve two problems simultaneously: the issue of excessive plastic waste, and also the need for light-weight insulators and absorbers:
“Plastic bottle waste is one of the most common type 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.”
Conducted by the Department of Mechanical Engineering at the National University of Singapore (NUS) Faculty of Engineering, the research team took two years develop the technology to fabricate PET aerogels. They are also looking into modifying the PET aerogels to be used for the absorption of toxic gases such as carbon monoxide.
Professor Nhan Phan-Thien from the Department of Mechanical Engineering at NUS Faculty of Engineering said:
“Our PET aerogels are very versatile. We can give them different surface treatments to customise them for different applications. For instance, when incorporated with various methyl groups, the PET aerogels can absorb large amounts of oil very quickly. Based on our experiments, they perform up to seven times better than existing commercial sorbents, and are highly suitable for oil spill cleaning.”
The research team has filed a patent for its novel PET aerogel technology, and hopes to work with companies to bring the technology to market.