Notices
Results 1 to 12 of 12

Thread: Zinc cyanide

  1. #1 Zinc cyanide 
    Forum Radioactive Isotope sculptor's Avatar
    Join Date
    Apr 2012
    Posts
    4,211
    argonne national labs applied extreem pressure to zinc cyanide and amazingly, it expands under pressure.

    ok
    that said:

    Why does it "defy the laws of physics" in so doing---why does zinc cyanide expand under pressure ?


    Reply With Quote  
     

  2.  
     

  3. #2  
    Bullshit Intolerant PhDemon's Avatar
    Join Date
    Feb 2013
    Location
    Newcastle-upon-Tyne, UK
    Posts
    4,430
    Are you sure it was zinc cyanide? I've never heard of anything like this for Zn(CN)2, the related compound zinc dicyanoaurate does show this behaviour. I remember reading about it here:

    Giant negative linear compressibility in zinc*dicyanoaurate : Nature Materials : Nature Publishing Group

    If you don't have access to that article it is covered in this blog:

    New transparent crystal expands under pressure | Science! | Geek.com

    (You are on my ignore list but my interest in chemistry overrode it)


    Reply With Quote  
     

  4. #3  
    Forum Radioactive Isotope sculptor's Avatar
    Join Date
    Apr 2012
    Posts
    4,211
    I read about it in a trade publication not a scientific journal, so ...accuracy of nomenclature remains in doubt.
    they referenced "Science daily"

    Thanks-will read linked material
    Reply With Quote  
     

  5. #4  
    Forum Radioactive Isotope sculptor's Avatar
    Join Date
    Apr 2012
    Posts
    4,211
    ok
    The team published the details of their work in the May 22 issue of the Journal of the American Chemical Society in an article titled “Exploiting High Pressures to Generate Porosity, Polymorphism, And Lattice Expansion in the Nonporous Molecular Framework Zn(CN)2 .”
    The scientists put zinc cyanide - See more at: Discovery of new material state counterintuitive to laws of physics | Argonne National Laboratory
    from:
    Discovery of new material state counterintuitive to laws of physics | Argonne National Laboratory

    and:
    We certainly were never expecting anything to increase in volume,” says Karena Chapman of Argonne National Laboratory, who led the group that published these results recently in the Journal of the American Chemical Society. “I don’t think anyone would. It’s against the laws of physics for something to expand under pressure.”

    Chapman and her colleagues managed to bend the laws of physics in this case by applying pressure to small fluid molecules—mainly methanol and water—surrounding the molecular framework material zinc cyanide, Zn(CN)2. The stable phase of zinc cyanide exists as tetrahedrally coordinated zinc ions bridged linearly by cyanide anions. Two of these frameworks interpenetrate in an overall non-porous, cubic system. At pressures of 0.9 to 1.8 GPa, the small molecules penetrated and induced reconstructive transitions in the zinc cyanide structure, replacing the interpenetrating networks with an open (non-interpentrating), porous structure with approximately twice the volume of the starting material. The liquid molecules wound up as guests in the pores of the new material. Using larger fluid molecules such as isopropanol or fluorinert as the pressurizing media led merely to compression of the starting zinc cyanide structure.
    from:
    Coordinated Framework Materials Expand Under Pressure - Materials360 Online

    so, is this new to you?

    really amazing?
    Reply With Quote  
     

  6. #5  
    Bullshit Intolerant PhDemon's Avatar
    Join Date
    Feb 2013
    Location
    Newcastle-upon-Tyne, UK
    Posts
    4,430
    Yep, news to me (materials science is not really my area of interest but I do tend to scan the Nature abstracts which is where I came across the article I linked to). I'll have a look at the links but from your quotes it appears to be due to forcing small molecules into the lattice which changes the structure.
    Reply With Quote  
     

  7. #6  
    Forum Radioactive Isotope sculptor's Avatar
    Join Date
    Apr 2012
    Posts
    4,211
    Quote Originally Posted by PhDemon View Post
    ... from your quotes it appears to be due to forcing small molecules into the lattice which changes the structure.
    That was my guess too........

    caveat: as/re "guess" this is way outside my normal fields of study
    imo basic research is often the underfunded orphan of science, and maybe the best?
    Reply With Quote  
     

  8. #7  
    exchemist
    Join Date
    May 2013
    Location
    London
    Posts
    2,532
    Quote Originally Posted by sculptor View Post
    argonne national labs applied extreem pressure to zinc cyanide and amazingly, it expands under pressure.

    ok
    that said:

    Why does it "defy the laws of physics" in so doing---why does zinc cyanide expand under pressure ?
    I don't think it defies the laws of physics. This looks like the usual journalists' hype. From what I read, it expands along one dimension. This would enable the material to respond to the pressure increase by reducing its overall volume (in accordance with "the laws of physics", but at the same time as extending itself along one axis.

    But I'm open to correction, as I didn't now anything about the phenomenon until you alerted me to it.
    Reply With Quote  
     

  9. #8  
    Forum Radioactive Isotope sculptor's Avatar
    Join Date
    Apr 2012
    Posts
    4,211
    Quote Originally Posted by exchemist View Post
    Quote Originally Posted by sculptor View Post
    argonne national labs applied extreem pressure to zinc cyanide and amazingly, it expands under pressure.

    ok
    that said:

    Why does it "defy the laws of physics" in so doing---why does zinc cyanide expand under pressure ?
    I don't think it defies the laws of physics. This looks like the usual journalists' hype. From what I read, it expands along one dimension. This would enable the material to respond to the pressure increase by reducing its overall volume (in accordance with "the laws of physics", but at the same time as extending itself along one axis.

    But I'm open to correction, as I didn't now anything about the phenomenon until you alerted me to it.
    exchemist:
    From what I understood from what I read, the zinc cyanide expands in volume, not along one dimension(as in the zinc dicyanoaurate mentioned by PhDemon above).
    Then, their reference to drying as part of industrial production process seems to support the idea that the expansion in volume is due to liquids being forced into the zinc cyanide making it sponge like. Which seems to be it's main value.

    Yeh, me too: I'm open to correction;
    and actually want it if/when I'm wrong.
    Reply With Quote  
     

  10. #9  
    exchemist
    Join Date
    May 2013
    Location
    London
    Posts
    2,532
    Quote Originally Posted by sculptor View Post
    Quote Originally Posted by exchemist View Post
    Quote Originally Posted by sculptor View Post
    argonne national labs applied extreem pressure to zinc cyanide and amazingly, it expands under pressure.

    ok
    that said:

    Why does it "defy the laws of physics" in so doing---why does zinc cyanide expand under pressure ?
    I don't think it defies the laws of physics. This looks like the usual journalists' hype. From what I read, it expands along one dimension. This would enable the material to respond to the pressure increase by reducing its overall volume (in accordance with "the laws of physics", but at the same time as extending itself along one axis.

    But I'm open to correction, as I didn't now anything about the phenomenon until you alerted me to it.
    exchemist:
    From what I understood from what I read, the zinc cyanide expands in volume, not along one dimension(as in the zinc dicyanoaurate mentioned by PhDemon above).
    Then, their reference to drying as part of industrial production process seems to support the idea that the expansion in volume is due to liquids being forced into the zinc cyanide making it sponge like. Which seems to be it's main value.

    Yeh, me too: I'm open to correction;
    and actually want it if/when I'm wrong.
    Well bugger me! (figuratively speaking, of course.)

    It seems to me the key passage in the paper is this one: "...While an increase in volume with pressure is counterintuitive, the resulting new phases contain large fluid-filled pores, such that the combined solid + fluid volume is reduced and the inefficiencies in space filling by the interpenetrated parent phase are eliminated."

    So it indeed does not disobey the laws of physics, because it becomes an open structure penetrated by the fluid used to apply the pressure. It seems that this that allows the new structure to occupy less space overall than the fluid + solid starting point.

    Reply With Quote  
     

  11. #10  
    Forum Radioactive Isotope sculptor's Avatar
    Join Date
    Apr 2012
    Posts
    4,211
    Interesting reading
    interesting approach
    I like that they listed their failures as well(different materials and different pressures...).
    Reply With Quote  
     

  12. #11  
    Forum Professor Zwolver's Avatar
    Join Date
    May 2006
    Location
    Netherlands
    Posts
    1,631
    Don't some larger organic compounds also expand when put under pressure? Mostly because pressure increases heat or friction, not that they form a crystal. (only small molecules do this)
    Growing up, i marveled at star-trek's science, and ignored the perfect society. Now, i try to ignore their science, and marvel at the society.

    Imagine, being able to create matter out of thin air, and not coming up with using drones for boarding hostile ships. Or using drones to defend your own ship. Heck, using drones to block energy attacks, counterattack or for surveillance. Unless, of course, they are nano-machines in your blood, which is a billion times more complex..
    Reply With Quote  
     

  13. #12  
    exchemist
    Join Date
    May 2013
    Location
    London
    Posts
    2,532
    Quote Originally Posted by Zwolver View Post
    Don't some larger organic compounds also expand when put under pressure? Mostly because pressure increases heat or friction, not that they form a crystal. (only small molecules do this)
    Er, well, compressing a gas increases its temperature, but the volume change when applying pressure to a solid is pretty small and won't change the temperature much. I can't see how friction would come into it. Nothing is rubbing, surely?

    Do you have examples of organic compounds that expand when compressed?
    Reply With Quote  
     

Similar Threads

  1. purchase cyanide pill
    By svarn44 in forum General Discussion
    Replies: 5
    Last Post: February 5th, 2013, 01:52 PM
  2. Potassium cyanide pills
    By sharma som in forum General Discussion
    Replies: 1
    Last Post: October 14th, 2012, 12:34 AM
  3. Cyanide suicide pills?
    By tombodrog in forum Health & Medicine
    Replies: 11
    Last Post: February 8th, 2012, 01:58 AM
  4. Replies: 4
    Last Post: July 17th, 2006, 05:09 AM
Bookmarks
Bookmarks
Posting Permissions
  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •