The researchers came up with a new way to remove microplastics from water

Researchers at the Princeton School of Engineering have found a way to turn your breakfast food into a new material that cheaply removes salt and microplastics
from seawater.

The researchers used protein to create an aerogel, a lightweight, porous material that can be used in a variety of applications, including water filtration, energy storage, sound insulation and heat
insulation.
Craig Arnold, the Susan Dod Brown Professor of Mechanical and Aerospace Engineering and associate dean of innovation at Princeton University, collaborates with his lab to create new materials
, including aerogels, for engineering applications.

One day, at a faculty meeting, he had an idea
.

"I sat there, staring at the bread in the sandwich," Arnold said
.
"I said to myself, this is exactly the kind of structure
we need.
" So he asked his lab team to mix carbon and make different bread recipes to see if they could reproduce the aerogel structure
he was looking for.
In the beginning, none of them worked well, so the team kept removing ingredients during testing until only egg whites
remained.

"We started with a more complex system," Arnold said, "and we kept decreducing, decreducing, decreasing, until we found its core
.
" It is the protein in the protein that causes the structure
we need.
”

Protein is a complex system of almost pure proteins that, when freeze-dried and heated to 900 degrees Celsius in an oxygen-free environment, form a structure
interconnected by carbon fiber chains and graphene sheets.
Arnold and his collaborators showed that the synthetic material could remove salts and microplastics
from seawater with 98 percent and 99 percent efficiency, respectively.

Sehmus Ozden, the paper's lead author, said: "Even if you fry it on the stove first, or beat it, the egg whites can work
.
" Ozden was a postdoctoral research assistant at the Center for Complex Materials in Princeton and is now a scientist
at the Aramco Petroleum Research Center.
Ozden said that while the initial test used regular protein purchased from the store, other similar commercially available proteins produced the same results
.

"Eggs are cool because we all have access to them and they're readily available, but you have to be careful about competing with food cycles," Arnold said
.
Because other proteins also play a role, this substance can be produced in large quantities at a relatively low cost without affecting the food supply
.
Ozden noted that the researchers' next step is to improve the manufacturing process so that it can be used for water purification
on a larger scale.

If this challenge can be solved, this material will have significant benefits due to its low production cost, high efficiency and efficiency
.
"Activated carbon is one of the
cheapest water purification materials.
We compared our results with activated charcoal and found that the effect was much
better.
"In contrast to reverse osmosis, which requires a lot of energy input and excess water operation, this filtration process only requires gravity operation and does not waste water
.

While Arnold sees water purity as a "significant challenge," it's not the only potential application for
the material.
He is also exploring other uses
related to energy storage and insulation.

The study included contributions
from the departments of chemistry, biological engineering and earth sciences at Princeton University and elsewhere.
"It's one thing to make things in the lab," Arnold said, "and it's another thing to understand why and how to do it
.
" Co-authors who helped answer the "why" and "how" questions included Rodney Priestley and A.
James Link from Professor Priestley and A.
James Link of Chemical and Biological Engineering, who helped identify the mechanisms
by which proteins are transformed at the molecular level.
Colleagues in Earth Sciences at Princeton University help measure water filtration
.

Suzanne Monti of the Institute of Organometallic Compound Chemistry and Valentina Tozzi of the Institute of Nanoscience and NEST-Scuola Normale Superiore created theoretical simulations that revealed the process by
which egg white proteins are converted into aerogels.