Adventures in Plasticizing (Mycelium post processing)


#1

So my experiments tend to focus on how to improve the material after it has grown.
Dried control Mycelium on long fibers.
In its natural state the hyphae doesnt seem to bind the fibers too strongly and we see some breaking along those lines.

Ethylene glycol and glycerol can be used to get into the fibers and block the space between fibers.Ethylene glycol as plasticizer. leads to a stiffer more thightly bound material.
Choline chloride:Ethylene glycol as plasticizer. on the other hand leads to a more flexible arrangement, the mycelium bends but the fibers don’t separate under the same forces.

All samples were courtesy of @Elise and then baked for 3 days at 60C after being soaked in the respective liquids for 48hours.

Edit: changed the videos to be on public onedrive rahter than the origianl floating GIF should work now


Method of making mycelium-leather
#2

@matthias the links are GIFs or videos, but are not working. Is it possible to upload videos directly to the forum?


#3

Not exactly, but you can embed them on this platform (example).

For that, you upload a video to YouTube or Vimeo, and post the link to the video on its own line in the editor, like this:

normal text … normal text … normal text … normal text … 

https://www.youtube.com/watch?v=xvagkP-bzy8

normal text … normal text … normal text … normal text …

The Discourse editor will then turn this into an embedded video. (This mechanism is known as “Onebox”, and works the same way in WordPress. Facebook has something similar as well.)


#4

@Gammarra: thanks for sharing these interesting results. As we are looking for new applications for the material, we bump into certain material limitations. However these plasticizers can broaden our scale of potential applications.
Two questions regarding these plasticizers:

  • Do you have any idea whether they will affect biodegradability of the mycelium material?
  • Can you give us some more information on the underlying reactions between mycelium (I assume chitine) and the plasticizers? That way we know which plasticizers we need to look for for specifici applications. Thanks!

#5

It might lower the rate of biodegration but not completely stop it. both ethylene glycol and choline choliride are, biocompatible, and relatively common molecules.

there are 2 possible mechanisms for pure EG:

Steric locking of the cellulose crystals, the EG enters the space in between the sugars of the cellulose chain and makes an hydrogen bond, this is a non binding interaction. since the EG will not evaporate like water the celullose and chitin become fixed in certain positions. Thus making a stiffer material

In presence of choline Chloride, a mild base. We might be seeing some increased crosslinking. The acidic H in the celullose and chitin become reactive and bind to each other or to the EG. Effectively increasing the binding between cellulose and chitin.


#6

My thinking is that, even though those chlorinated compounds are common, the resulting concentration of chlorine can be sufficiently high to be toxic for biological systems.

If you have a 500gr pot made mainly from material stiffened with ethylene glycol, and it degrades in your garden over 4 months, that would account to a lot of chlorine. This is a total stab in the dark, I don’t know the numbers or effects exactly.


#7

https://www.sciencedirect.com/science/article/pii/S0045653512013513
Typical concentrations would be 10%w at the most. Which still would be biologically managable


#8

Hi Gammarra,

Is it fair to say that using EG with a very aggressive base can increase mycelium flexibility?
And what about highly saline water - could that be used?
:slight_smile:


#9

saline wont do much, the main issue with using NaOH and EG will be solubility but you would be able to dilute both in water at least, so I would start there rather than in a pure EG solution