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Egg whites can be transformed into a material capable of filtering microplastics

156 points| wglb | 3 years ago |phys.org | reply

56 comments

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[+] random42_|3 years ago|reply
Curiously egg whites are also used to remove particles from stock (chicken, veal, beef) when you want to have a crystal clear liquid.
[+] Larrikin|3 years ago|reply
I found this a very interesting technique when you posted it, but I actually wonder now if there is much point to it. Most of the gunk is filtered out when making a stock when you pass it through a sieve and/or a cheese cloth.

OfIs a clear broth actually something that matters besides a gate keeping technique in French cuisine?

[+] wirrbel|3 years ago|reply
First thought I had : grandma used to clarify broth with eggs.

Iirc you can also use it to prepare coffee when camping. The egg binds to ground coffee in a saucepan so it’s better separated from the coffee you pour into your mug

[+] mcv|3 years ago|reply
The title just mentions microplastics, but the first line of the article says:

> a way to turn your breakfast food into a new material that can cheaply remove salt and microplastics from seawater.

So salt too? Isn't that way more impressive than microplastics? Could this lead to cheap desalination?

[+] kul_|3 years ago|reply
But then, how will you separate salt from microplastics?
[+] moneytide1|3 years ago|reply
> "I was sitting there, staring at the bread in my sandwich," said Arnold. "And I thought to myself, this is exactly the kind of structure that we need."

Reminds me of Eli Whitney seeing a cat defeather a chicken while trying to pull it through a fence, inspiring the cotton gin (learn from nature). Wasn't the original Starlite also derived from edible matter [0]?

They started with the bread because of its spongey texture (fine, compacted flour expanding as yeast yields gas) but arrived at the egg white protein structure which is less apparent to the naked eye (the light color implies low density solid? Polar bears appear white but hair is clear, which means more empty space thus insulated?).

> Egg whites are a complex system of almost pure protein that—when freeze-dried and heated to 900 degrees Celsius in an environment without oxygen—create a structure of interconnected strands of carbon fibers and sheets of graphene.

I wonder if this rapid temperature change is embrittling the structure (squeeze with cold then stretch with heat) causing it to fragment into the "two dimensional" graphene sheets after being depleted of everything but the carbon. But the carbon fiber protein strands are cylindrical - how is this leading to flat one-atom thick sheets? Perhaps this rapid temperature gain to a specific 900C is akin to the specific resonant frequency that will shatter the crystalline structure of glass.

Robert-Murray Smith has experimented with graphitizing various natural materials like banana peels, seaweed, wood, and coffee grounds [1].

[0] https://youtu.be/0IbWampaEcM?t=256

[1] https://youtu.be/a3_XU-nva5o?t=121

[+] bell-cot|3 years ago|reply
Here's a slightly-critical bit...if you wanted to do this at massive scale, without inducing massive starvation:

> "Eggs are cool because we can all connect to them and they are easy to get, but you want to be careful about competing against the food cycle," said Arnold. Because other proteins also worked, the material can potentially be produced in large quantities relatively cheaply and without impacting the food supply. One next step for the researchers, Ozden noted, is refining the fabrication process so it can be used in water purification on a larger scale.

[+] MisterBastahrd|3 years ago|reply
Egg whites have only been used for centuries in French cuisine as a method for clarifying liquids.
[+] somenewaccount1|3 years ago|reply
+ Aerogel. That will be $1 million dollars now please. Thank you.
[+] d--b|3 years ago|reply
The stuff seems great but one has to ask: what kind of bread is that guy eating that has egg whites in it?!
[+] erulabs|3 years ago|reply
White bread is often made with egg whites to give it that super dense but fluffy/spongy texture it's famous for.
[+] electric_mayhem|3 years ago|reply
How about ground flax seeds? Or aquafaba?

They work in other contexts as egg substitutes…

[+] adamjc|3 years ago|reply
FTA, it's a protein found in egg whites:

> Because other proteins also worked, the material can potentially be produced in large quantities relatively cheaply and without impacting the food supply.

[+] likpok|3 years ago|reply
There are vegan flocculants -- guinness switched a while back, making their beer vegan.
[+] iancmceachern|3 years ago|reply
Or that goo that surrounds chia seeds when soaked
[+] otar|3 years ago|reply
Interesting… I use egg whites to remove the sediments from the wine.
[+] Timpy|3 years ago|reply
I'm really confused by this, I tried finding some videos online but it looks like they're all just mixing egg whites into their wine. How do you get the egg out of the wine?
[+] lakomen|3 years ago|reply
Why does it have to be egg white and not any other protein?
[+] shultays|3 years ago|reply
It doesn't

    "Eggs are cool because we can all connect to them and they are easy to get, but you want to be careful about competing against the food cycle," said Arnold. Because other proteins also worked, the material can potentially be produced in large quantities relatively cheaply and without impacting the food supply.
[+] markbnine|3 years ago|reply
Aren't microplastics already in chickens? Do they get passed to the eggs? If so, where do you filter microplastics first. . . the chicken or the egg?
[+] chaostheory|3 years ago|reply
Don’t buy cheap eggs. The plastic is introduced via the feed, through vectors like expired bread products. There’s nothing wrong with using expired baked goods. The issue comes when they don’t take off the plastic wrapping and just let everything be shredded into the feed.

I do not believe grass fed chickens have the same problem.

[+] boarush|3 years ago|reply
My, my, a new chicken and egg problem!

But seriously, this does raise genuine concerns about what is the acceptable limit for microplastics in the egg whites initially, since microplastics have made way to everything we consume today.