American scientists have found a way to turn egg whites into a new material that can cheaply remove salt and plastic particles from seawater.
Previous studies have shown that 24.4 trillion microplastic particles are polluting the oceans, which requires finding ways to filter these particles.
— Princeton University (@Princeton) November 5, 2022
The scientists noted that the proteins in egg whites could be used to form what is known as an airgel, a type of lightweight, porous material that could have a variety of potential uses, including water filtration, energy storage, and sound and heat insulation.
— Phys.org (@physorg_com) November 4, 2022
Materials scientist Professor Craig Arnold of Princeton University in New Jersey said the path to this breakthrough actually began with a completely different food, as he had an idea while sitting in a faculty meeting.
“I was sitting and looking at the bread in the sandwich and I thought, ‘This is exactly the structure we need,'” he said.
Based on this, Professor Arnold and his colleagues set out to make different types of bread mixed with carbon to see if they could create the aerobic structure they were looking for.
Since none of the original recipes worked, the team began to refine the ingredients during testing until only the egg white was left at the end.
Professor Arnold noted that he started with a more complex system until he and his team got what they needed: “It was the proteins in the egg white that led us to the structures we wanted.”
According to him, egg whites are a complex system of almost pure protein, and when freeze-dried and heated to 900 degrees Celsius in an oxygen-free environment, he creates a structure of interconnected filaments of carbon fibers and sheets of graphene.
This material is capable of removing both salt and microplastics from seawater with 98% and 99% efficiency, respectively.
“Egg whites work even if they are first fried on the stovetop or beaten,” added author Dr. Samos Ozden of Aramco Research.
While the team used store-bought egg whites in their initial tests, Dr. Osden explained that other similar commercially available proteins also produced similar results, meaning the substance could be produced cheaply and on a large scale without affecting food stocks. nutrition.
After completing the initial study, the researchers are now looking to improve the material’s production process so that it can be used for large-scale water treatment.
Not only are their materials efficient and cheap to manufacture, but they are also energy efficient, as only gravity is required to operate, unlike alternative technologies such as “reverse osmosis” (a water treatment method), which are more expensive, the team says. energy.
Dr. Osden added: “Activated carbon is one of the cheapest materials used for water treatment. We compared our results with activated charcoal and they were much better.”
The full results of the study are published in Materials Today.