AsianScientist (Nov. 12, 2018) – Researchers from the National University of Singapore (NUS) have turned plastic bottle waste into aerogels. They published their findings in Colloids and Surfaces A.
Plastic waste is toxic and non-biodegradable. Such waste often ends up in oceans and landfills, affecting marine life and causing problems such as groundwater contamination and land scarcity. Globally, the annual consumption of plastic bottles has been rising steadily and it is expected to exceed half a trillion tons per year by 2021.
Plastic bottles are commonly made from polyethylene terephthalate (PET). In the present study, researchers led by Associate Professor Duong Hai Minh have found a way to convert PET into aerogels—porous solid materials with customizable properties.
The PET aerogels they produced are soft, flexible, durable, extremely light, easy to handle and demonstrate superior thermal insulation as well as strong absorption capacity.
“One plastic bottle can be recycled to produce an A4-sized PET aerogel sheet. The fabrication technology is also easily scalable for mass production,” said Duong.
The researchers also found ways to add unique functions to their PET aerogels. For instance, when various methyl groups were incorporated, the PET aerogels could absorb large amounts of oil very quickly. In experiments, the modified PET aerogels performed up to seven times better than existing commercial sorbents, said the scientists.
When coated with fire retardant chemicals, the novel lightweight PET aerogel was able to withstand temperatures of up to 620 degrees Celsius. This is seven times higher than the thermal lining used in conventional firefighter coats, despite the aerogel weighing only about ten percent of conventional fire-resistant materials.
By adding an amine group to the PET aerogel, the researchers gave it another function—the ability to quickly absorb carbon dioxide from the environment. Its absorption capacity is comparable to materials used in gas masks, which are costly and bulky. To illustrate this application, the team embedded a thin layer of PET aerogel into a commercial fine particle mask to create a prototype mask that can absorb both dust particles and carbon dioxide effectively.
“Our PET aerogels are very versatile. We can give them different surface treatments to customize them for different applications… 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 Duong.
The article can be found at: Salomo et al. (2018) Advanced Fabrication and Properties of Hybrid Polyethylene Tetraphalate Fiber–silica Aerogels From Plastic Bottle Waste.———
Source: National University of Singapore; Photo: Pexels.
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