TECH

Plastic bottle turns solid smoke

Airgel of PET
Researchers at the National University of Singapore (NUS) have made a significant contribution to solving the global issue of plastic waste.Steven Salomo and his colleagues have created a way to convert PET bottles (polyethylene terephthalate) into aerogels.Aerogels are very light materials - they are called "solid smoke" -, soft, flexible, durable and easy to handle. They also have excellent thermal insulation capacity and, as they are more air than matter, a strong absorption capacity.These properties make them attractive for a wide range of applications, such as thermal and acoustic insulation in buildings, oil spill cleanup and also as a lightweight coating for fire coats and carbon dioxide absorption masks, which could be used during rescue and fire.

"A plastic bottle can be recycled to produce an A4 size airgel sheet. Manufacturing technology is also easily scalable for mass production, so we can help reduce the environmental damage caused by plastic waste," said the professor. Hai Minh Duong, team coordinator.

Dust and gas mask
The team has already tested various ways to use their PET airgel.When coated with fire-retardant chemicals, the PET airgel resists temperatures up to 620 ° C - that is seven times more than the thermal coatings used in current firearms, and weighing only about 10% of the weight of the conventional material. The smooth and flexible nature of PET airgel also provides greater comfort.When coated with an amine group, the PET airgel absorbs rapidly the carbon dioxide from the environment. Its absorption capacity is comparable to that of materials used in gas masks, which are expensive and bulky. To illustrate this application, the team incorporated a thin layer of PET airgel into a fine particle mask capable of absorbing particles of dust and carbon dioxide - that is, gas and aerosols filtered through the same mask.Researchers are now working on techniques to make surface modifications of PET aerogels to make them capable of absorbing toxic gases such as carbon monoxide, which is the most lethal component in pollution.


Bibliography:
Advanced manufacturing and properties of hybrid polyethylene tetraphalate fiber-silica aerogels from plastic bottle waste
Steven Salomo, Thanh X. Nguyen, Duyen K. Le, Xiwen Zhang, Nhan Phan-Thien, Hai M.Duong
Colloids and Surfaces A: Physicochemical and Engineering Aspects