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New Form of "Mobius" Carbon Predicted 115

Posted by kdawson
from the with-a-twist dept.
KentuckyFC writes "We've seen carbon nanotubes, buckyballs, and chickenwire. Now materials scientists have created a computer model of a Mobius strip fashioned from strips of graphene — a molecule that would have a single surface and only one edge. (Other groups have made Mobius-like organic molecules but never out of carbon sheets.) The model allows the researchers to determine the physical and chemical properties of the molecules and how these depend on the number of twists in the strip. The team says, for example, that 'Mobius carbon' should be stable to temperatures of at least 500 Kelvin (abstract). But the most exciting prediction is that strips with an odd number of half twists should have a dipole moment that would cause them to self-organize into a crystal. That implies that there's a new type of carbon made entirely of Mobius strips ready to be made by any chemists with a good supply of graphene (maybe these guys)."
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New Form of "Mobius" Carbon Predicted

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  • 1st post (Score:2, Funny)

    by Anonymous Coward

    I wrote the first post on the Moebius strip I wrote the first post on the Moebius strip

  • V'Ger (Score:1, Funny)

    by stevedmc (1065590)
    V'Ger will comply, if the carbon units give the information
  • Insight required (Score:5, Interesting)

    by w0mprat (1317953) on Monday March 16, 2009 @09:50PM (#27220377)
    Do these have useful properties at all? Where's the (wild and unfounded) speculation?

    paper: http://arxiv.org/abs/0903.2080 [arxiv.org]
    • Re:Insight required (Score:5, Interesting)

      by elashish14 (1302231) <profcalc4&gmail,com> on Monday March 16, 2009 @11:00PM (#27220919)

      Graphene has some pretty interesting electronic properties. Its bandgap (the essential component of all semiconductors) can be manipulated by changing the length of the sheet; as the sheet becomes infinitely long, the bandgap approaches zero. As a result, it could hold potential in photovoltaics for light capture or LEDs for light emission where capture/emission is tunable based on the size of the particle (which is pretty easy to manipulate).

      Another article popped up on Slashdot recently suggesting graphene could be used for super high-capacity memory storage: http://hardware.slashdot.org/article.pl?sid=08%2F12%2F18%2F2332251. [slashdot.org]

      From the paper they mention that active electrons have near-zero effective mass. Since electron mobility is inversely proportional to effective mass, resistivity approaches zero (in essence, we approach superconductivity). As far as twisted graphene ribbons go, the paper only mentions that there's some weird ground state orbital morphologies (triplet states and open singlet ground states) which I'm not familiar with but also have to do with interorbital transition which always has applications in light emission/absorption technologies. I believe that lasers heavily depend on triplet states to create inversion layers, but don't quote me on that.

      As far as it goes anyway, even if you don't know what the properties will be, you might as well study it - you never know what's going to come out.

      • by feranick (858651) on Tuesday March 17, 2009 @12:50AM (#27221593)

        Graphene has some pretty interesting electronic properties. Its bandgap (the essential component of all semiconductors)

        Graphene is a semimetal. The bandgap is zero in suspended graphene. Epitaxial graphene on SiC has a small gap (0.1meV) but below Fermi level, so not very useful.

        can be manipulated by changing the length of the sheet; as the sheet becomes infinitely long, the bandgap approaches zero.

        Not correct. The bandgap of a narrow ribbon depends on the width (not the length) of the ribbon. Above 10nm there is no gap, below there is, regardless how long it is.

        As a result, it could hold potential in photovoltaics for light capture or LEDs for light emission where capture/emission is tunable based on the size of the particle (which is pretty easy to manipulate).

        Well, this is totally unrelated as electron-hole pair recombination requires a junction.

        Another article popped up on Slashdot recently suggesting graphene could be used for super high-capacity memory storage: http://hardware.slashdot.org/article.pl?sid=08%2F12%2F18%2F2332251. [slashdot.org]

        From the paper they mention that active electrons have near-zero effective mass. Since electron mobility is inversely proportional to effective mass, resistivity approaches zero (in essence, we approach superconductivity).

        No. mobility is finite, because you need to take into account of the so called saturation velocity. Besides, near-zero doesn't mean zero, so conceptually the two are completely different.

      • by msouth (10321)

        Graphene has some pretty interesting electronic properties. Its bandgap (the essential component of all semiconductors) can be manipulated by changing the length of the sheet; as the sheet becomes infinitely long, the bandgap approaches zero

        Yeah, in theory. I've actually got an infinitely long sheet and I'm about to test that, just waiting to hear back from the lab assistant I sent to the other end.

      • by Twinbee (767046)

        Don't we have enough knowledge about the carbon atom so as to predict the properties of this new material? Or is it that we do have the knowledge, but lack the necessary computing power? (e.g. would 1000000000000x faster PC be able to perfectly simulate the material?)

    • Well, they would in all likelihood be extremely tough for their size and weight. If they figure out how these can be produced in large quantities, maybe we can interleave the loops, and create nanotube "chainmall". That would be an awesome material.

      How is that for "wild and unfounded speculation"?

      • One property of a mobius ring is that if the ribbon is cut along its length, it falls apart into two interlocked loops, each new ring passing through the hole in the middle of the other (two rings simply linked together).

        If the original band that gets twisted and joined into a mobius ring had a weak "seam" down its middle, perhaps other chemical/physical means could then split it along that seam. Like perhaps an enzyme solution working on a protein seam "doped" into the middle of the graphene strips alongsi

        • One property of a mobius ring is that if the ribbon is cut along its length, it falls apart into two interlocked loops, each new ring passing through the hole in the middle of the other (two rings simply linked together).

          No! No! No!

          That is, you're doing it wrong.

          When cutting a a mobius ring parallel to its edge, the first cut produces a single loop twice as big as the original, with a full twist (so it is no longer a mobius ring). If you cut THAT parallel to its edges, then you end up with the two interlocked loops.

          Try it. Go ahead, give it the old empirical test.

          • by Doc Ruby (173196)

            OK, so what you mean is "No! No!... Yes!" :)

            The splitting of these kinds of loops sounds like it's even more powerful a technique than I (fuzzily) recalled. And if the loops can be rezipped, so those three states with their different properties can be selected, then that kind of material could be really interesting. Especially if different areas can be un/zipped among the states.

    • by Lars T. (470328)
      I guess no SF writer ever came up with something like it, so there is no one to quote (badly) for speculation.
    • by HTH NE1 (675604)

      Do these have useful properties at all?

      Well, if they get torn down their middle, they still produce only one strip but with a full twist. Do it again and you get two strips that are linked to each other. Self-entangling rings of carbon have gotta be useful somehow.

  • by B1oodAnge1 (1485419) on Monday March 16, 2009 @09:56PM (#27220415)

    A Mobius strip is bad for your back.
    I think I'll just stick with the Pole strip for now thanks.

  • by LaminatorX (410794) <sabotage.praecantator@com> on Monday March 16, 2009 @09:58PM (#27220443) Homepage

    Can you imagine a Klien Bottle made of these?

    • by AstrumPreliator (708436) on Monday March 16, 2009 @10:17PM (#27220601)
      Yes I can, but can you imagine a Real Projective Plane made of these? Neither can I =(.
    • Re: (Score:1, Funny)

      by Anonymous Coward

      Can you imagine a Klien Bottle made of these?

      Imagine a mobius strip made of these!

    • by reverseengineer (580922) on Tuesday March 17, 2009 @12:14AM (#27221363)
      I think you could make a molecular Klein bottle, though of course you would have the same limitation as for any Klein bottle immersed in three dimensions- a self-intersection would be necessary. This would probably rule out a physically realizable Klein bottle made purely out of graphene, as a self-intersection would either involve carbon atoms bonding to 5 or 6 other carbon atoms (extraordinarily unlikely) or bonds with significant angle strain and steric hindrance if you tried to squeeze the self-intersecting tube through the lattice instead of bonding to it. If you didn't mind including some higher-valent atoms rather than just carbon, it could probably be constructed.
    • by yo303 (558777) on Tuesday March 17, 2009 @03:29AM (#27222231)

      A mathematician named Klein
      Thought the Mobius strip was divine.
      Said he, "If you glue
      The edges of two
      You'll get a weird bottle like mine."

  • by StupidPeopleTrick (1006681) on Monday March 16, 2009 @09:58PM (#27220449)
    I am wondering the chemistry applications of this. I bet you can make some very interesting compounds out of this material. A one sided molecule kind of redefines limiting agent would it not? - StupidPeopleTrick
    • by onepoint (301486) on Monday March 16, 2009 @10:22PM (#27220645) Homepage Journal

      I am having a hard time picturing a 1 sided molecule. I would guess I can picture 2 sides ( top / bottom ) but 1 side? way more advanced than I can currently think, can someone offer an example.

      • Re: (Score:3, Funny)

        by NemoinSpace (1118137)
        Start over again with Hydrogen, now take the BLUE pill.
      • The example is in the name. Mobius [wikipedia.org]

        • by onepoint (301486)

          wow, most amazing, and rather cool, I am surprised that no one used this as automotive belts for cars

          • The twist would weaken the belt considerably. So would the bending back and forth. And getting the pulleys involved at the angles necessary to keep the belt from rubbing sounds like a mechanical nightmare.
          • Re: (Score:1, Flamebait)

            by GaryOlson (737642)
            The automotive unions would never allow such an item. More work would be required to install a twisted one-sided belt than a non-twisted two sided belt. The union would get less pay for a belt with fewer sides.
          • by mcvos (645701)

            wow, most amazing, and rather cool, I am surprised that no one used this as automotive belts for cars

            I think that has actually been done. Or maybe it was some other application. You do need a certain amount of length to keep the twist from messing up.

            • by onepoint (301486)

              >>You do need a certain amount of length to keep the twist from messing up

              Now that I understand the concept, the twist is easy to manage, by keeping the twist in a certain segment of the entire loop of the belt, you can avoid the belt from moving the twist ( avoid it fro moving forward or backwards )

              I'm not to an engineer, but to keep the belt in place I would have roller guilds over a length ( think tiny rolling pins ), each guild slightly offset in the clockwise ( or counter clockwise ) direction un

      • by kratib (793460)
        Take a one-sided molecule, flip it half a turn, and you see... the same side!
      • Re: (Score:3, Interesting)

        by MrNaz (730548) *

        To be honest, calling a Mobius Strip "one sided" is not strictly correct. It's just a twist that causes one side to join with the other such that all points on both sides can be traced to each other without having to traverse an edge. Clever, yes. Truly one-sided in the dimension collapsing sense? No.

        Mobius Strips are great for befuddling stupid people though. If you tell the average person that you can show them a piece of paper with one side they laugh. Then you give them a Mobius Strip and a pencil, draw

        • by aldo.gs (985038)

          If a MÃbius Strip isn't one-sided, could you please give an example of something that is?

      • Re: (Score:3, Informative)

        by Gibbs-Duhem (1058152)

        Graphene is a (basically) 2-D sheet that can be fairly large. Imagine the sheet the size of a blanket. Now make a mobius strip out of it.

        The fact that it's "one sided" should only really come into play in that long range hybridization of the pi orbitals will interfere with each other -- presumably causing the weird effects their model predicts.

      • by reverseengineer (580922) on Tuesday March 17, 2009 @02:56AM (#27222109)
        Locally (to the individual atoms, for example) a Mobius molecule is double-sided. Each carbon atom is fixed in a plane in graphene, though the point here is that the plane is interestingly warped. A chlorine atom could attack a carbon atom from above the plane and a bromine atom could attack from below the plane, and that would be a physically meaningful description. "Above" and "below" are of course arbitrary distinctions; let's use "a" and "b" in this post. From the perspective of Carbon #1 of the 150 carbon atoms in this molecule, the situation is nothing special; there's a bit more bond strain from the way the lattice is twisted, but it still generally behaves like a carbon atom.

        What makes a Mobius molecule interesting is when you something else along its surface. For example, kinesin [wikipedia.org] is a protein that works like a set of molecular legs. Picture a regular, non-Mobius single-walled carbon nanotube, a rolled-up sheet of graphene. This tube has an exterior surface (the "a" position)and an interior surface ("b")- it is two sided. To get a kinesin molecule from the exterior surface to the interior surface or vice versa, you must either cut through the graphene lattice or walk to an edge of the cylinder and flip around. There is not a smooth, continuous path from position Carbon #1-a to #1-b for a regular nanotube.

        However, for a Mobius nanostrip, that added half-twist makes the "exterior surface" continuous with the "interior surface," making a smooth path possible. If you place kinesin at Carbon #1-a and have it walk around the strip, halfway through the course (for a strip with one half-twist), the kinesin will be at Carbon #1-b (in other words, back at Carbon #1, but in a local sense, on the other side of the sheet), and its orientation will be flipped 180 degrees from the original. If the kinesin keeps going, eventually it returns to its original orientation at Carbon #1-a. If you put a kinesin molecule at both 1-a and 1-b and sent them off walking in opposite directions, they would eventually collide.

        Locally, 1-a is on the opposite side of 1-b, but a kinesin molecule can smoothly and continuously walk from 1-a to 1-b (or any other point) without breaking bonds in the graphene lattice or flipping around an edge to another side. Therefore, in terms of its entire shape, a Mobius molecule is one-sided.
        • by naoursla (99850)

          Interesting. I wonder if biology uses mobius strips for channels through membranes. I'm imagining a gauntlet of proteins along the mobius strip that move things along the surface and reject things before they get to the other side.

    • Re: (Score:3, Informative)

      by Gibbs-Duhem (1058152)

      Doubt it. Things can still react on both sides of the locally 2-sided graphene sheet.

  • Now they just need to perfect it for water [wikipedia.org].
    • by Nasajin (967925)

      Other groups have made Mobius-like organic molecules but never out of carbon sheets.

      I perfected it for paper. Years ago. I'm sure we all have.

  • Bike Frames? (Score:3, Interesting)

    by MarkvW (1037596) on Monday March 16, 2009 @10:04PM (#27220501)

    Will this do anything for bicycle frames?

    • by syousef (465911) on Monday March 16, 2009 @10:10PM (#27220533) Journal

      Will this do anything for bicycle frames?

      Yes. Now you'll be able to rid a bike on Venus. You'll disintegrate in 30 seconds but the bike frame won't. Have a nice ride.

      • Re: (Score:1, Funny)

        by Anonymous Coward

        I, for one, cannot /wait/ for Bikerfox (NSFW) [encycloped...matica.com] to begin investing in this new Venus-Capable technology.

      • by Lars T. (470328)
        Surface temperature of Venus is well over 500 Kelvin.
        • by syousef (465911)

          Surface temperature of Venus is well over 500 Kelvin.

          I was waiting for that. Yes they are. It's a joke, it doesn't need to be technically accurate.

          • by Lars T. (470328)

            Surface temperature of Venus is well over 500 Kelvin.

            I was waiting for that. Yes they are. It's a joke, it doesn't need to be technically accurate.

            Yeah, it only needs to be accurate to be a good joke. You may continue with fart jokes.

            • by syousef (465911)

              Yeah, it only needs to be accurate to be a good joke. You may continue with fart jokes.

              If your criteria for a joke being good is it's scientific accuracy I submit that you are in no position to advise me on humour.

    • Re: (Score:3, Funny)

      by rubycodez (864176)

      no, but if you put a sheet of them in a clothespin with the end in the spokes, they make a neat engine sound

    • by fractoid (1076465) on Monday March 16, 2009 @10:29PM (#27220693) Homepage
      Of course, it'll allow manufacturers to gyp 50-year-old men who aren't quite committed enough to their mid-life crises to buy sports cars into paying an extra $2k for Mobius bike frames that shave an extra 200 grammes off the weight of a 6kg bike. These men will then lean said bikes against the railings of expensive snobby coffee shops at 7am and drink coffee while pretending that it's OK to sit around wearing brightly coloured skintight lycra when you're over 50. Sadly, they will never actually realise that the whole point of a 'cafe racer' bike was that it HAD AN ENGINE.

      Also, Mobius bike frames will have the added bonus that they even more easily pretzel into a mobius strip themselves when confronted with a kerb, pot-hole or other such part of the Real World.
      • by JustNilt (984644)

        Now that was funny, in a slightly unsavory way. Well done.

      • by Kozz (7764)

        Hey. Those 50-year-old men pay my salary (indirectly) at a large international bicycle company. Don't write them off just yet. Besides, the multi-thousand dollar carbon frames are definitely for the serious road bike enthusiasts and while they're an important part of our annual sales figures, we've been selling carbon fiber frames for road bikes and mountain bikes for several years. (Want to see a *really* expensive bike? Check out some high-end carbon hardtail frames.)

        But I digress.

        • You might be the right person to ask this. I commute on a fairly good mountain bike. My biggest maintenance issue is with the rear gear shift. The nine speed system is must harder to keep calibrated than my old seven speed bikes. It really is a PITA.

          The hydraulic disc brakes OTH are absolutely fantastic. Easily 10 times easier to maintain than cable actuated caliper brakes.

          So I would love to see a hydraulic gear shift. Do you know if anybody is working on that? It would be fantastic.
          • You might want a bike shop to check for chain stretch (should take about a minute; they'll have the right tool). Also whether the chain is the correct one for the index shifters (even if it is the "original" chain: picking the wrong chain during assembly can happen). As the number of cogs goes up, the allowable tolerances on chain dimensions get a lot more narrow. (Also have the shop evaluate wear on the chain rings at the same time they check for chain stretch: if the chain is bad, the chainwheels get chew

    • by GaryOlson (737642)
      Yes, but you have to turn the frame over and see the other side to really understand.
    • In theory, the joins of Moebius tubes will be twice as strong as using standard tube-and-lug fabrication, since there will be only one edge on each tube. That is, assuming that current topological problems in designing the lugs can be overcome with today's geometry.

      Arcane frame building humour aside, the first likely bicycle application is prolly going to be in the tires. A Moebius tire will roll twice as far with half the wear, which would have obvious value on utility and commuting bikes.

  • by mbenzi (410594)

    When they can produce a Klein Bottle I will be impressed. Still not sure either will be be useful, but I will be impressed.

  • Diamonds (Score:2, Interesting)

    by gnieboer (1272482)

    My first thought would be that:
    Carbon Crystal = Diamond

    So handmade custom 'Mobius Diamonds' could be the new rage

    My second though was that
    Carbon Nanotube Crystal != Diamond

    Diamonds are carbon crystals at the atomic level, where is sounds these crystals would be at the molecular level (molecules being bonded groups of atoms)
    So they probably would not share all the characteristics of diamonds. I'd be interested to see what they look like though.

    IANAChemist, so I'm curious to hear from someone more qualified

    • Re:Diamonds (Score:5, Informative)

      by Gibbs-Duhem (1058152) on Tuesday March 17, 2009 @12:14AM (#27221367)

      Well, it will still be made up of graphene when it comes to looking at atomic energy levels. Band gap is the primary source of light interactions, and as it will still be close to zero band gap (unless the asymmetry thrown into long range hybridization screws it up in ways I am not thinking of), and should be absorbing most photons.

      So, it'll probably look the same as graphite, but would probably diffract photons with wavelenghts like 10nm due to it having a longer-range crystal structure than normal crystals (which only diffract in the X-rays). The crystals might do things like diffract in the high energy UV, assuming the UV doesn't all get absorbed by the graphite.

  • Ants? (Score:5, Funny)

    by antdude (79039) on Tuesday March 17, 2009 @12:54AM (#27221631) Homepage Journal

    Will these Mobius strips have ants on them? ;)

  • As they only have one side would these be able to be used to create monopoles?
  • Oh wow, that's stable within a handful of degrees of boiling water.

    I'm very curious what it may be good for, but that little factoid makes it sound and feel like buzzword useless hype.

    • Re: (Score:3, Informative)

      by Anonymous Coward
      Water boils at 373K. If you call 127K a "handful of degrees" you are either an american or a retard with really big hands. 500 Kelvin = 226.85 Celsius (water boils at 100c)
  • Hmm (Score:5, Funny)

    by troon (724114) on Tuesday March 17, 2009 @04:59AM (#27222589)

    Article seems a little ... one-sided.

    I'll get my coat.

  • i got my girlfriend to shave her pubes into a Mobius Strip

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