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Looking for an unusual material

  1. Nov 17, 2014 #1
    Dear all, I'm a university student in charge of developing a biochemical device (reactor) for the depuration of leather factory wastewaters, this is an european project leaded by Ambiental Engineering University of Florence. Part of this device should be colonized with fungi in order to purify water, and they (the fungi) need a biodegradable material (cellulose, starch) with a certain porosity to grow, but it also has to be non-soluble in water. The material should also be cheap and easy to find. Until now I've looked at some biodegradable polymers such as PLA, PCL, some fibers (bagasse, hemp) and even foams (starch foam pellets are produced as insulating materials), wich seemed to be the best choice... too bad they're water soluble. What do you think? Is there any material or composite or something else you're thinking about?

    MB
     
  2. jcsd
  3. Nov 17, 2014 #2

    mfb

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    Can you coat a porous material with a biodegradable material? That would remove one restriction from the material and move it to a second material.
     
  4. Nov 17, 2014 #3

    NTW

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    Biodegradable, porous, and non-soluble in water...
    What about wood...?
    It's cheap and easy to find, too...
     
  5. Nov 18, 2014 #4

    Danger

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    This might be overly simplistic, but what about natural living sponges? What you want done is pretty much what they do when they're left all by their lonesomes in the ocean.
     
  6. Nov 19, 2014 #5
    This is a possible way, even if the coating process could raise up the costs. Maybe a mater-bi coated sponge-like material could work...
    Wood could be a good way too, but lignin is a bit difficult to decompose for the fungi, they prefer more simple substances like cellulose or amylum, and the pores (I didn't mention that, I know) should be large about 1-2 mm.

    The material needs to have an high surface/volume proportion, and it made me think about the structure of lungs.

    Yes! The sponge would have the perfect structure, but unfortunately it seems that the "spongin", the material of the sponges, is a protein (similar to collagene) and it's not the best option for fungi.

    Thank you for your interesting suggestions, they were very useful for my brainstorming! I'd be pleased to hear more from you, you look brilliant!
     
  7. Nov 20, 2014 #6

    NTW

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    May I suggest several layers of cotton gauze wound over a skeleton of stainless steel wire that could keep the desired form...?
     
  8. Nov 24, 2014 #7

    Danger

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    Whoa, now! What about a collagen scaffold, or animal bones with holes drilled them?
     
  9. Nov 25, 2014 #8
    Yes this is interesting, simple and easy to make as a mass production! The correct folds could make an high proportion in surface/volume too!

    The bones could work as well, but it would a bit harder on the production side.

    At the moment my team is studying the potential use of Ecovative mushroom material. A substitute of Polystirene made with agricoltural waste and mushroom's mycelium, it could get interesting. Meanwhile I'm searching for other potential materials.
     
  10. Nov 25, 2014 #9

    Danger

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    I'm about out of ideas. Please make sure to keep us informed of your progress even if the thread starts to lapse due to lack of input. I'm really interested to see what you come up with.
     
  11. Dec 1, 2014 #10
    Man, I really appreciate your interest. I'll keep the thread updated. At the moment we need to test the process of fungal biosorption and in order to do that I'm developing a 3D printed sample tester which has to be similar to a polyurethane foam cube. We'll send the tester in Turin, to our mycologist associates and we'll see.
     
  12. Dec 1, 2014 #11

    Danger

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    Great! That should make selection a lot easier.
     
  13. Dec 23, 2014 #12
    How about cellulose or luffa sponges?
     
  14. Jan 13, 2015 #13
    Dear all, the experimentation is still going on, we are now trying to make "cellulose pies" using yeasts to add porosity. With scarce results for now, but we're improving. I'm also developing other testers that consist in one thermoplastic net with a cellulose paste on it. In this case I used water, cellulose pulp, and amylum paste as a thickener, but i would need something that doesn't melt in water (amylum does).

    Luffa is a very good idea, in fact the mycologists are already testing it, the only "con" is that has large pores in the central part of its section and tynier ones in the outer part. This causes the fungi to create a "core" in the larger room: sometimes it's useful, but sometimes it creates a sort of barrier which doesn't let substances flow through.

    While luffa is a good idea cellulose sponge is a brilliant idea. I don't know if we can use the currently commercialized ones, because I guess they are treated against mould but we'll try that. Anyone has an idea of how they produce them anyway? This could be very useful because our problem with cellulose is that we can't make a compact porous solid that stays compact after being dryed and rehydrated
     
  15. Jan 14, 2015 #14
    Natural kind of cellulose sponges are made out of wood or vegetable fibers. I know Trader Joe's here (https://www.amazon.com/Trader-Joes-Sponges-Vegetable-Cellulose/dp/B008XLGDDQ) imports them from France so you might find it somewhere in Europe or figure out how they make them. I think they match all your requirements. These ones are not treated with any chemicals, so they get filthy pretty quickly, which is a good thing in your case.
     
    Last edited by a moderator: May 7, 2017
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