Molecules bound by chains...

[BigMoosie]

Molecules exist that are as a ring of atoms with a hole, would it be possible to connect these like a chain? Could you imagine having a chain mail vest made of a single molecule thick substance? It would be incredibly very flexible but incredibly strong as you would have to physically break covalent bonds. Any advances with such technology that anybody is aware of?

[Godless Wonder]

Would it really be all that strong?

When you break something, say a stick, or a piece of iron, or a piece of plastic or styrofoam or glass what exactly happens? Aren't you breaking bonds? (Just ionic bonds? But really isn't there a continuum between ionic and covalent bonding?)

You can't just stick the pieces back together and have the item join back together.

[Dhaeron]

<snip>
When you break something, say a stick, or a piece of iron, or a piece of plastic or styrofoam or glass what exactly happens? Aren't you breaking bonds?<snip>
Nope. The molecules in your stick remain intact, you only ovecome the inter-molecular forces. At least if the material is not a crystallic.
If breaking atomic and ionic bonds is harder than that, i can't say. I couldn't stand the physical chemistry lectures. :Cheeky:

[Godless Wonder]

Nope. The molecules in your stick remain intact, you only ovecome the inter-molecular forces. At least if the material is not a crystallic.
If breaking atomic and ionic bonds is harder than that, i can't say. I couldn't stand the physical chemistry lectures. :Cheeky:

What about styrofoam (polystyrene) isn't it an example of a chained, gigantic molecule? Or maybe it's more like a molecular felt than a molecular chain mail?

[BigMoosie]

Covalent bonds are many many multiple times stronger than ionic bonds. Instead of having positive ions stick to negative ions, you have electrons orbiting the nuclei of the atoms. To break this usually requires a chemical reaction.

[Sven]

Molecules exist that are as a ring of atoms with a hole, would it be possible to connect these like a chain?
Well, a beginning was alread made (http://www.iupac.org/goldbook/C00904.pdf).
See also http://en.wikipedia.org/wiki/Polycatenane

Could you imagine having a chain mail vest made of a single molecule thick substance? It would be incredibly very flexible but incredibly strong [...]
And incredible difficult to synthesize. [2]catenanes are difficult enough.

[BigMoosie]

What about styrofoam (polystyrene) isn't it an example of a chained, gigantic molecule? Or maybe it's more like a molecular felt than a molecular chain mail?

That is a chain yes, but not in the sense that I mean it. They are linked together by molecular bonds, the chain that i refer to is linked together just by their spacial location.

@ SVEN - Thankyou for those links, however brief they may be, at least now that I know the name of them I can do some searching

[hagiograph]

Graphite sheets are hexagonal rings of carbon bonded like a hexagonal tile pattern. The C-C bond is pretty strong (hence diamond is hard), but the reason graphite is "soft" is because these sheets are held against other sheets by relatively weak van der Waal's forces. But the sheets themselves are reasonably strong if memory serves correctly.

Diamond is not "sheet-like" but more like ice in that the carbon is in a framework. Graphite is the same chemical except the carbons are bonded into flat sheets. (The difference between sp2 and sp3 hybridization of the s and p orbitals)

Another alternative might be mica minerals or other PHYLLOSILICATES. These are made up predominantly of sheets of silica tetrahedra that share corner oxygens in hexagonal rings.

-h.

[camp freddie]

A single molecule thickness of anything isn't going to be very strong.

Since a chain is only as strong as its weakest link, you only need to break one covalent bond per ring, which is no big deal.

Covalent bonds have a strength of about 300 KJ/mol. This is about the same as many ionic bonds (i.e. salt, which is quite easy to break). Each bond would therefore be about 10^-17 joules.

This means that the energy required to lift an apple from the floor to waist height could break 100000000000000000 covalent bonds.

The gaps in the chainmail would make the substance very light, but sadly not very strong.

Lastly, forming an ordered chainmail structure would be almost impossible, since you'd be fighting entropy all the way. There is no way of ensuring that your rings join together in a chain instead of as free 'links' or (most likely) that the ends of the ring monomers don't meet each other (to form the rings) and instead meet the end of another monomer (forming a normal, straight line polymer).

It would make some interesting substances if it were possible, but sadly it isn't!

[starling]

I think you refer to a benzene ring (http://www.wsws.org/articles/2003/oct2003/bush-o23.shtml)? (tricyclohexene IIRC) One thing you have to consider with these things, is the 'rings' formed are just a bunch of overlapped electron waves. Not mixed, or combined, but overlapped. I say not mixed because the wave is the sum of each individual electron, but does not modify that electron cloud's behavior. Just like when you make two ripples in a pond, they don't mix, but instead cause a moire pattern from their sums, each travelling as if the other did not exist, in overlap. Or the fact that when you shine a light horizontal to the earth, it doesn't interfere with the sun's light passing through its beam, and therefore does not cast a shadow.

Okay, so what those rings are is the apex of the standing wave that is the independant sum of each individual electron cloud. That means though it's the maximum, the space inside, and outside the boundary of the ring is affected: just the way a water wave is bell-shaped, trailing off slowly, not a single vertical peak of water. So if you 'linked' two chain links together, it would be like two waves in a pond meeting: probably some funky 3D moire pattern that ended up with the two links more likely to spread apart.

When the sum of two or more of the same molecule is stable, that's the definition of a polymer. Or a crystal I guess. Polymers are like 1 dimensional crystals maybe? A polymer isn't usually interlocking rings though. There are other ways, since the links have a positive core to attract each other, not just repulsion as with the metal chain links we're familiar with.

I think the diagrams of benzene are misleading. There isn't really much space 'inside' the ring. The carbon atoms are pretty much crammed closely together as possible. Think like a really fat donut without a hole.

But not all is lost! What you should be studying are carbon nanotubes (http://www.wsws.org/articles/2003/oct2003/bush-o23.shtml). Those are 'strands' of molecules that are just about as strong and durable as anything we've cooked up. They even hypothesize that if such tubes ever become useful enough to make cabling out of, we could make a cable durable enough to reach geosynchronous orbit (http://www.wsws.org/articles/2003/oct2003/bush-o23.shtml), fully 26 times stronger than steel.

In other news, goats are producing spider silk (http://www.wsws.org/articles/2003/oct2003/bush-o23.shtml).

[starling]

See also http://en.wikipedia.org/wiki/Polycatenane:wide: They really have thought of everything!

[hagiograph]

I think you refer to a benzene ring (http://www.wsws.org/articles/2003/oct2003/bush-o23.shtml)? (tricyclohexene IIRC) One thing you have to consider with these things, is the 'rings' formed are just a bunch of overlapped electron waves. Not mixed, or combined, but overlapped. I say not mixed because the wave is the sum of each individual electron, but does not modify that electron cloud's behavior. Just like when you make two ripples in a pond, they don't mix, but instead cause a moire pattern from their sums, each travelling as if the other did not exist, in overlap. Or the fact that when you shine a light horizontal to the earth, it doesn't interfere with the sun's light passing through its beam, and therefore does not cast a shadow.


I am fascinated by this post. Are you saying the C-C bond is nothing more than an electron interference pattern? While I understand that the bond is the overlap of orbitals, it seems like your prior statement would indicate that the bond is not very strong. Maybe I'm misreading the point of the post. I think you are on target in terms of the physical "nature" of a bond (but that isn't my area of chemistry), but don't let that lead you to believe that the bond is ethereal and without some strength.

But then you point out:

But not all is lost! What you should be studying are carbon nanotubes (http://www.wsws.org/articles/2003/oct2003/bush-o23.shtml). Those are 'strands' of molecules that are just about as strong and durable as anything we've cooked up. They even hypothesize that if such tubes ever become useful enough to make cabling out of, we could make a cable durable enough to reach geosynchronous orbit (http://www.wsws.org/articles/2003/oct2003/bush-o23.shtml), fully 26 times stronger than steel.,

Carbon nanotubes are made up of what amounts to benzene rings (same kind of C-C bonds) that share sides, like an hexagonal tile pattern. In the case of a carbon nanotube this sheet of joined benzene rings is rolled up like a sheet of paper. In the case of MWNT (multiwalled nanotubes) there are several sheets rolled up nested one inside the other. In the case of SWNT (singlewalled nanotubes) there is only one sheet rolled up.

You are quite correct, there is some evidence there are very strong materials.


Okay, so what those rings are is the apex of the standing wave that is the independant sum of each individual electron cloud. That means though it's the maximum, the space inside, and outside the boundary of the ring is affected: just the way a water wave is bell-shaped, trailing off slowly, not a single vertical peak of water. So if you 'linked' two chain links together, it would be like two waves in a pond meeting: probably some funky 3D moire pattern that ended up with the two links more likely to spread apart.

Lost me on this part.


In other news, goats are producing spider silk (http://www.wsws.org/articles/2003/oct2003/bush-o23.shtml).

Very cool indeed. I've heard some folks talk about this. One of our summer interns last year formerly worked with a researcher who was working on this project. It sounds absolutely cool. I pointed out, though, that the hard part was milking the goats, what with all 8 legs in the way.

-h.

[BigMoosie]

Another interesting molecular structure is the buckyball, it is a spherical shaped molecule that can have other molecules placed inside them which cannot escape, good for storing dangerous substances because the trapped particles cannot react

[Sven]

I think you refer to a benzene ring (http://www.wsws.org/articles/2003/oct2003/bush-o23.shtml)? (tricyclohexene IIRC)
Sorry, but this made my head hurt. If anything, it's cylcohexatriene (tricyclo means something containing three rings; more specifically, a compound in which you have to cut three bonds to get an open chain).
But in reality, benzene isn't cylcohexatriene, the latter simply does not exist because of the delocalization of the electrons; all six C-C bonds are equal, "in between" a single and a double bond.

I say not mixed because the wave is the sum of each individual electron
The wave function is rather the product of the wave functions of the individual electrons. So the rest of your post didn't make sense.

When the sum of two or more of the same molecule is stable, that's the definition of a polymer. Or a crystal I guess. Polymers are like 1 dimensional crystals maybe?
There are also polymers in 2 or 3 dimensions.

A polymer isn't usually interlocking rings though. There are other ways, since the links have a positive core to attract each other
:huh: Which postive core are you talking about?

I think the diagrams of benzene are misleading. There isn't really much space 'inside' the ring. The carbon atoms are pretty much crammed closely together as possible. Think like a really fat donut without a hole.
Depends on how you look at it. The electron density in the middle of the ring is certainly much smaller than between any two atoms "in" the ring. And since the wave function of any electron bound by a nucleus extends to infinity anyway, your argument could as well be used to say that there's no empty space at all.

But not all is lost! What you should be studying are carbon nanotubes (http://www.wsws.org/articles/2003/oct2003/bush-o23.shtml). Those are 'strands' of molecules that are just about as strong and durable as anything we've cooked up. They even hypothesize that if such tubes ever become useful enough to make cabling out of, we could make a cable durable enough to reach geosynchronous orbit (http://www.wsws.org/articles/2003/oct2003/bush-o23.shtml), fully 26 times stronger than steel.

Carbon nanotubes are really fun (I even thought about doing my diploma in this field some years ago), but IMHO, it's more hype than facts.

[Sven]

Another interesting molecular structure is the buckyball, it is a spherical shaped molecule that can have other molecules placed inside them which cannot escape, good for storing dangerous substances because the trapped particles cannot react
The buckyball is only one out of the family of so-called fullerenes (http://en.wikipedia.org/wiki/Buckminsterfullerene), which exist (if memory serves me correctly) from C_48 to C_(several hundred).
The buckyball itself is C_60; they were named after Buckminster Fuller and his famous geodesic domes (http://en.wikipedia.org/wiki/Buckminster_Fuller), which have the exact same topology.
One can show (quite easily, but I forgot the proof nevertheless) that all those balls have a different number of hexagons, but always exactly 12 pentagons.

[uncool]

I believe that the buckeyball is the highest shape that only allows pentagons and hexagons.
First thing, you cannot have 3 hexagons around 1 vertex - they would add up to 360 and make a flat side, which should not be allowed.
Therefore, at each vertex there are either 1 or 2 pentagons. To have the maximum number of vertices, we would want there to be one pentagon at each vertex (otherwise, the total angle would be less, and the structure would close in on itself faster). This structure (with one pentagon and two hexagons at each vertex) is the Buckey Ball.
-Uncool-

[BigMoosie]

Here is a picture of a nanotube:

http://www.icpf.cas.cz/jiri/pictures/nanotube.jpg

as you can see there are vertexes that are made up of 3 joining hexagons, in fact the whole thing is hexagons except for the couple of pentagons at either end.

[MortalWombat]

Could you imagine having a chain mail vest made of a single molecule thick substance? It would be incredibly very flexible but incredibly strong as you would have to physically break covalent bonds. Any advances with such technology that anybody is aware of?
Breaking covalent bonds of very long molecules through physical force is no big deal. When isolating genomic DNA, for example, it's virtually impossible to get completely intact DNA because of the shear forces caused merely by disrupting the cell and getting the DNA into solution.

[BigMoosie]

I wasnt aware of that

[Agemegos]

Could you imagine having a chain mail vest made of a single molecule thick substance?

Yes. It would fold itself over any bladed edge and form a one-molecule thick coating on the blade, like a very thin layer of grease. The coated blade would then cut me in half. But at least the blade wielder would be able to pull it out easily. At most, this might prevent my blood from rusting the blade.

The reason that one gets such terrible bruising and broken bones through mail is that it doesnt' spread teh impact of a blow out very far. This stuff you suggest wouldn't spread it out at all.

And really, I don't think that a single molecule would be all that strong. The energy in a single covalent bond is not much compared to what I generate by metabolising covalent bonds by the millimole.

[Sven]

as you can see there are vertexes that are made up of 3 joining hexagons, in fact the whole thing is hexagons except for the couple of pentagons at either end.
Indeed. If you count the pentagons, you see that you have six at each end, making the 12 I mentioned in my post above, since both ends fused together again give C_60.

[BigMoosie]

I was responding to this comment: [qote]First thing, you cannot have 3 hexagons around 1 vertex[/quote]

[Majestyk]

In other news, goats are producing spider silk (http://www.wsws.org/articles/2003/oct2003/bush-o23.shtml). Uhmmm.... Is there something hijacking my browser or is there another reason this link is taking me to the World Socialist News site where there is no mention of silk?

[BigMoosie]

I think that fella who posted that was just being wise.

[BioBeing]

Uhmmm.... Is there something hijacking my browser or is there another reason this link is taking me to the World Socialist News site where there is no mention of silk?
How did that happen? Did it go there before (I thought I clicked on it, but obviously not).

Try this one (http://www.howstuffworks.com/news-item38.htm) instead. If this goes astray, we'll know its a conspiracy!

[BigMoosie]

I just realised something! A buckyball is the same shape as a soccerball!

[Sven]

I just realised something! A buckyball is the same shape as a soccerball!
Right. :)
That's the revelation everyone hearing about it arrives at sooner or later.