In light of the staggering amount of plastic waste being generated in the world, the scientific community is engaged in active efforts to devise strategies centered around containing the materials or converting them into new materials which will give them a second life. From plastic-eating fungus to developing creating biodegradable plastic, dozens of ideas are being put forth.
A group of researchers from the National University of Singapore (NUS) have developed a method that tackles one of the biggest offenders: plastic bottles. They set out to convert the bottles into an aerogel, a porous and ultralight solid that offers a promising list of applications.
A Branding Strategy Emerges
PETs, also known as polyethylene terephthalate, are the most common polymer resin in the world that goes into producing plastic bottles. It seems only logical, then, to name the new creations "PET aerogels", a term which describes the growing body of scientific research centered around the process involving the reuse of the toxic and non-biodegradable substances. Although rPET-silica aerogels are not new, this is the first time that they have been developed from plastic bottles.
“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,” explains NUS Associate Engineering Professor Hai Minh Duong.
What the researchers' work seems to indicate is that efforts are being made to make the development of PET aerogels a common industry standard, which would mean securing a patent and collaborating with industry leaders to standardize the process.
The aerogels, beyond possessing (1) oil, (2) carbon dioxide and (3) dust particle absorbing qualities, also withstand temperatures up to 620°C despite their lightweight composition, making it a kind of super material.
In terms of industrial applications, the team envisions them being used for sound and heat insulation in various buildings, as a lining alternative in coats made for firefighters, and even in masks that absorb carbon dioxide, which could prove a great benefit for firefighters and other types of first response teams. In other words, rPET-silica aerogels are not only a soundly sustainable option, but also the practical advantages are numerous.
“This new eco-friendly cotton aerogel is a major improvement from the aerogel that our team had previously developed using paper waste. It is highly compressible, hence storage and transportation costs could be greatly reduced. Furthermore, these cotton aerogels can be fabricated within eight hours – this is nine times faster than our earlier invention and about 20 times faster than current commercial fabrication processes.
They are also stronger, making them more suitable for mass production. "While we have demonstrated a novel application of the cotton aerogels for effective hemorrhage control and heat insulation, we will continue to explore new functions for this advanced material,” explained Professor Duong.
Details about the 2-year study appear in a paper, titled "Advanced fabrication and properties of hybrid polyethylene tetraphalate fiber–silica aerogels from plastic bottle waste", which will be published this month in the Colloids and Surfaces A: Physicochemical and Engineering Aspects journal.