Direct Observation Of Chemical Reactions

Mouth of Sauron writes "I saw on C|net that researchers with IBM have devised a way to directly observe chemical reactions as they occur in a liquid with an electron microscope. Frances Ross of IBM was awarded the Burton Medal by the Microscopy Society of America. Researchers say this could lead to a better understanding of chemical reactions and could have impact far beyond the computer industry."

They could already do this in dry environs

[Elwood P Dowd]

The new advantage is that they can make 30 fps observation of chemical reactions in a liquid. Previously, they could get 30 fps in gas or solids, and they could get 3 fps in liquid, but now they can get both at high speed.

Really interesting. I want to hear what they're learning.

Re:They could already do this in dry environs

[Henry V .009]

High speed? 30 fps is the bare minimum for me. I won't even watch a chemical reaction until it's at least 60 fps. And do you know if they put the 3DMax scores into the paper?

30 fps is just convenient, not the ultimate.

[MZdoctor]

The original paper explains how they squeezed their own experiment into a conventional TEM set-up consisting of an environmental cell in an intermediate voltage Hitachi TEM equipped with a Gatan energy filter. The final magnified image is captured from a fluorescent screen with a monochrome video camera. If a higher frame rate were necessary all it would require is a different CCD with a higher clock rate. The TEM itself produces a continuous image just like a light microscope.

The emphasis put by C/Net on

silicon nitride?

[js7a]

...transmission microscopes--which shoot electrons through micron-thin samples of materials and then form an image from data about the resulting paths of the electrons--depend on placing the sample in a strong vacuum. That's fine for observing reactions between solids and gases, but it doesn't work for reactions with or inside liquids.

"In ordinary circumstances, the liquid would just boil away," Ross said.

Biological samples viewed under a transmission electron microscope have to be initially dehydrated, which can change their shape.

To get around that problem, IBM devised a cell chamber that captures a layer of liquid and the elements to be studied between two silicon nitride membranes.

"You can think of the cell as an extremely sophisticated (microscope) slide," she said.

How come a silicon nitride membrane strong enough to hold a liquid away from a vacuum doesn't diffract or deflect electrons? Is there something special about silicon nitride that makes it transparent to electrons?

Neat trick, but I'm not sure if I'm willing to believe it without an explanation. Si3N4 has a dielectric constant of 7.5; what gives?

Re:silicon nitride?

[tsa]

The use of SixNy (almost never really Si3N4 because of its huge internal stress) for membranes for transmission electron spectroscopy is quite common. You can make very thin membranes (in the order of 50-100 nm). They are very strong and thin enough for the electrons to tunnel through. With two of these layers placed very near each other you can keep the liquid in between them and still use them for TEM. And because they are non-crystalline they don't show up in the pictures that much.

This is still slow.

[Snags]

Even this "high speed" 30 fps is still too slow to actually watch an individual chemical reaction. The amount of time it takes for a copper atom to bond to the electrode, once it gets there, should be much less than a microsecond. Most of the time in "slow" reactions is waiting for the next reactant to come along. At room temperature, a copper atom in a liquid moves at about 340 m/s = 760 MPH!

You can watch a cluster grow, though. So, they can watch where the first atom deposits, then the second, etc.

Re:This is still slow.

[Noren]

But catching an atom in the act of bonding would be quite difficult.

Yes, chemical reactions occur very quickly, but there are ways of detecting them- a recent nobel prize [nobel.se] was awarded for femtosecond spectroscopy using pulsed lasers. (a femtosecond is 10^-15 seconds)

Re:This is still slow.

[Snags]

That is true. But I don't think they're using pulses of electrons that are that short. If they were, it would have been mentioned or even featured in the article.

If you want fast...

[kevinatilusa]

You could always talk to Ahmed Zewail (1999 Nobel laureate in Chemistry). His work was on using laser flashes to gather images over a time scale of femtoseconds (10^-15 seconds). I'm not sure how detailed these pictures would be, however, or if the method would be viable in liquid.

Fast but zoomed out.

[Snags]

The picture detail from light isn't nearly as good as from electrons. In electron microscopy, you can (barely) see the positions of individual atoms, which are a few Angstroms apart. Laser light has a much larger wavelength (>1000 Ang) and hence gives less resolution.

how about a nuclear reaction?

[axxackall]

And finally I wanna see those quarks - otherwise it's hard to believe they exist.

Re:how about a nuclear reaction?

[BrokenHalo]

Little things like quarks are hard to see, but I would like to see what they manage to make of any the reactions of organic compounds and substrates. It would be a real challenge to be able to make sense of that mess visually.

Hell, what about this one: tha action of LSD on the brain?

Re:how about a nuclear reaction?

[suitti]

I wanna see those quarks
Photons are quarks. Your eye can detect single photons, unaided.

Priorities

[SandSpider]

Researchers say this could lead to a better understanding of chemical reactions and could have impact far beyond the computer industry.

I mean, I know we're computer geeks and all, but did researchers really first think, "Wow, this is going to impact the computer industry for sure!"? Or perhaps did they think of, for example, medicine, where chemical reactions are common during the practice, rather than during manufacturing stage, which is the only time chemical reactions in a liquid are really going to matter.

Brian

Re:Priorities

[JabberWokky]

Since the researchers were from IBM, I'd imagine the authors were making it clear that it impacted more than the employer's major field of industry.

--
Evan

Re:Priorities

[Smidge204]

Well, if you bothered to RTFA, it talks specifically about how the process was used to study interactions with copper atoms, and how they are going to apply it to improving chip manufacturing.

So yeah, I guess they did consider that this is going to impact the computer industry. :P
=Smidge=

Re:Priorities

[SandSpider]

Well, if you bothered to RTFA...

I wanted to try this out....

*Ahem* You're new here, aren't you?

Thank you, I'll be here all week.

Seriously, though, yeah, I should have read the article. And if I had, I would have said:

Researchers say this could lead to a better understanding of chemical reactions and could have impact far beyond the computer industry.

Well, duh.

=Brian

quantum interfearence

[JDizzy]

Would the use of electron bombardment cause the classical quantum conundrum where direct observation of particles affects their quantum state, and I suppose their non-quantum existance? I'm actually suprised this hasn't happened already. Electron microscopes normally have to look at very still stuff, and a chemical recation isn't still by any measure. But photographing moving stuff would seem to be the next logical step (still pictures, motion pictures). I'd like to see some microscopic movies of fire (combustion) in action! ;)

Re:quantum interference

[jwdg]

I suspect that it would be a problem in some cases - their example (clustering of metal atoms) is possibly less sensitive to excess electrons passing through than some others might be. I'm not sure that it's necessarily quantum interference either.

The other thing worth mentioning is that depending on the process you're observing, the 1 frame/30 seconds offered by competitor technologies may not really be a problem. Some reactions are slow! (About 10-15 years ago, the oxidisation of Si(111) 7x7 was one of

Re:quantum interference

[rhombic]

Some day when I get bored, I'll build myself an STM...

You mean like here [geocities.com]?

Re:quantum interference

[jwdg]

Yes.

And I wasn't joking - I was involved in a university "improvised STM" project once, so I can just about remember how to do it. The piezo element was nearly the most expensive bit of the thing for that one as well.

beyond?

[Transcendent]

Researchers say this could lead to a better understanding of chemical reactions and could have impact far beyond the computer industry."

Since when did all science work in the favor of just the computer industry? You make it sound like we apply all new knowledge and then worry about the rest afterward. I would think that the computer industry would be one of the last to benefit. FIRST you would go through cleaner chemical processing, better-made biodegradable materials, more advanced propulsion systems (more efficient, really), better food processing, stronger materials.... and then maybe someone will apply this to semiconductors.

The most obvious applications do not envolve computers... I hope everyone else here has a more open mind.

Re:beyond?

[Ritontor]

New technologies get applied to the industries who will show the most economic reward first. The IT industry is right up there...

Re:beyond?

[illuvata]

we might not apply all new knowledge to the computer industry, but researchers at IBM probably do.
hint if you didn't bother to read the sumamry: this was developed by IBM

Profound discoveries?

[Anonymous Coward]

...could lead to a better understanding of chemical reactions and could have impact far beyond the computer industry.

We already know mixing alcohol and driving can cause huge impacts!

Had that back in the '60s...

[Black Parrot]

<jayleno>They called it L-S-D.</jayleno>

Scientists invent gassy vacuum...

[JohnPM]

...depend on placing the sample in a strong vacuum. That's fine for observing reactions between solids and gases...

Um, strong vacuum != gases. Heh.