Chemistry World podcast - June 2013


Audio Files

The Chemistry World podcast is sponsored by Waters – world leaders in innovative analytical science solutions. Visit waters.com for more information.

1.00 Gold nanoparticles can help to spot spoilt food with a new colour-changing system - Plasmonic milk monitor collars spoilt dairy

4.10 Acoustic dispensing – using sound waves to move discrete volumes of fluid – seems to be more accurate than traditional pipetting techniques - Sound approach to drug testing

7.05 Eleanor Campbell walks us through 300 years of chemistry at Edinburgh University - Capital chemistry

13.54 A new technique that splits water but releases the oxygen and hydrogen in separate stages could allow for safer long term hydrogen storage - Split water splitting raises green hydrogen hopes

17.24 ‘Inverse vulcanisation’ can turn sulfur – a by-product of petroleum refining – into new and useful polymers - Radical approach to turn sulfur into polymers

19.55 Doug Stephan tells us how the main group elements are back in vogue after years languishing behind more fashionable areas of research - Main group renaissance

26.28 Coating insect larvae with Tween-20, a common detergent, lets them survive the powerful vacuum inside an electron microscope - Polymer ‘nano-suit’ protects insects from vacuum

30.12 What can we do with the waste created by burning biomass for energy? Convert it into useful porous silicates - Sieving silica sieves from biomass ash

32.29 Trivia: Joseph Black of Edinburgh University discovered carbon dioxide on the 11th June 1754. In the last month, the amount of the gas in our atmosphere passed the milestone of 400 ppm.

Full transcript

Interviewer – Chris Smith

This month a nanoparticle solution to spotting when food might be going mouldy, a way to store hydrogen safely but as protons not as a gas, and a protective suit, so living tissue can be imaged alive under the electron microscope. This is the Chemistry World podcast and is sponsored by Waters- the World Leaders in Innovative Analytical Science Solutions. Visit http://www.waters.com for more information.

Hello, I'm Chris Smith and also with us for this the June 2013 edition of Chemistry World are Andrew Turley, Bibiana Campos-Seijo, and Emma Stoye who’s been looking at a visual sensor system for keeping food safe.

(1:03 - Gold nanoparticles can help to spot spoilt food with a new colour-changing system - Plasmonic milk monitor collars spoilt dairy)

Interviewee – Emma Stoye

So, this is a new system for labelling milk or may be other foods that go off quite easily that can tell you whether it might have gone off or not.

Interviewer – Chris Smith

People have been talking about making these sorts of food monitor labels for long time haven’t they? What’s different here?

Interviewee – Emma Stoye

Yeah, they can monitor these things, they can use quite expensive electric sensors to tell whether food has gone off and then display it on the outside – a sort of data looking technology. But this is really expensive, and it may be the sort of thing that will be more useful for transporting a batch of these things then, say, an individual carton of milk and so what’s new about this is that they’re actually using something that just produces a simple colour change and they’re using gold nanoparticles.

Interviewer – Chris Smith

How does it work?

Interviewee – Emma Stoye

You get these gold nanoparticles that are just 12 nanometres thick and disperse them through an agar gel. The gold doesn’t actually look gold, it looks bright red because of the way light bounces off these nanoparticles and interacts with them. They actually put silver nitrate and ascorbic acid, the ascorbic acid reduces the silver nitrate and you actually get silver, which kind of plates the gold nanoparticles and changes them into silver nanoparticles and they appear green.  So, overall you get this colour change from red to green over time and what they’ve managed to do is calibrate it so that this reaction occurs at the same speed as the growth of the kind of bacteria which make milk go off.

Interviewer – Chris Smith

So, it’s an index of temperature then, average temperature at which the food stuff has been stored.

Interviewee – Emma Stoye

Yes. That’s right. This reaction speeds up when the temperature increases, just like the growth of bacteria kind of speeds up when the temperature increases.

Interviewer – Chris Smith

So, it doesn’t tell you the food is necessarily unsafe, as in it’s not saying ‘there are microorganisms in here’, but it is saying ‘this food has not been kept at an ideal temperature, it haseen warmed up at some point, so there could be a risk’.

Interviewee – Emma Stoye

Yeah that’s right. It’s saying, you know, may be this milk has been left out in the sun or left on the door step, which is what

Interviewer – Chris Smith

Is that not your nose is for? To sniff and say ‘that smells pretty iffy, I’m not going to drink that’.

Interviewee – Emma Stoye

Maybe. May be you want to sniff it. This is more likely to allow you to tell before you even open the carton of milk and it’s perhaps a little bit more accurate, measuring the rate at which these bacteria have grown. Sometimes you can’t always smell it. I’ve definitely put some in on my cereal before it’s got to the taste stage before I realize I’ve made a terrible mistake.

Interviewer – Chris Smith

It sort of spoils the day a bit, doesn’t it when this happens?

Interviewee – Emma Stoye

Yeah, it really does, it’s not the best thing to happen in the morning.

Interviewer – Chris Smith

Is it just milk or could other food stuffs also be protected in the same way?

Interviewee – Emma Stoye

Yes. They could use this to protect other food stuffs. In fact, it may be more important than for milk because if you have some off milk  it’s may be a bit unpleasant, but it’s not nearly as bad as having off chicken say or fish that can make you quite ill.

Interviewer – Chris Smith

Thanks Emma. More information on that story on the chemistry world web site.

(4:07 - Acoustic dispensing – using sound waves to move discrete volumes of fluid – seems to be more accurate than traditional pipetting techniques - Sound approach to drug testing)

Interviewer – Chris Smith

Bibi, a sound way to approach drug testing, tell us more.

Interviewee – Bibiana Campos-Seijo

There are three authors that have got together here, Sean Ekins, Joe Olecho, who works for Labcyte, a company that develops acoustic dispensing technology and the third one is Antony Williams from the Royal Society of Chemistry. He is the brains behind ChemSpider. The three of them got together to look at how standard pipetting technology compares with acoustic dispensing.

Interviewer – Chris Smith

Now I’ve never heard until you mentioned it of acoustic dispensing. I was brought up as a Gilson man, dip the pipette in, thumb down thumb up – that’s your sample, so what are the other ways of measuring a known quantity of something?

Interviewee – Bibiana Campos-Seijo

Acoustic dispensing uses high frequency sound waves to eject droplets of solution upwards into an inverted multiwell plate, the surface tension will make it stay there until dilution takes place.

Interviewer – Chris Smith

So what is the story here?

Interviewee – Bibiana Campos-Seijo

The story here, is that they looked at patent data published by AstraZeneca for 14 drug candidates that were used to inhibit a receptor, a protein called EphB4.  They looked at all of those and they had data for potency for each compound that was measured or had been measured after pipette based and acoustic dilutions.

Interviewer – Chris Smith

These are two different techniques. So you’ve got the pipette technique versus the acoustic spraying technique.

Interviewee – Bibiana Campos-Seijo

Yes, and basically they were trying to compare potency data for each set of data.

Interviewer – Chris Smith

What did they find?

Interviewee – Bibiana Campos-Seijo

That it was very different.

Interviewer – Chris Smith

In which direction, which is better?

Interviewee – Bibiana Campos-Seijo

The acoustic dispensing was by far more accurate. They found that the data were between 1.5 and 150 fold different.

Interviewer – Chris Smith

Good grief that’s huge!

Interviewee – Bibiana Campos-Seijo

What these guys did, as well, using software and  computational methods they looked at producing a model of how biological compounds interact with small molecules and they actually discovered different predictions in terms of what molecules were going to be biologically active.

Interviewer – Chris Smith

So, drug A is better than drug B if you use a standard pipette, but if you use this acoustic technique, you may get a very different outcome, so it could have quite important impacts on the outcome for a pharmaceutical company in other words.

Interviewee – Bibiana Campos-Seijo

It is very serious actually because they exactly found that one was suggesting a drug that would have hydrophobic features while if you’re using the pipette model, it didn’t forecast the same type of behaviour. It is also worth thinking about historically what decisions have been taken it terms of what drug candidates have been taken forward, maybe it is worth revisiting some of those decisions and seeing whether we have missed something.

Interviewer – Chris Smith

So, how many other drugs have we missed, owing to a pipetting error? Thanks Bibi.

(7:05 - Eleanor Campbell walks us through 300 years of chemistry at Edinburgh University - Capital chemistry)

Interviewer – Chris Smith

This year marks the 300th Anniversary of the founding of the Department of Chemistry at University of Edinburgh. How does now compare with then?

Edinburgh cityscape

© Jon Arnold Images Ltd/Alamy

Interviewee – Eleanor Campbell

I’m Eleanor Campbell, I’m the current chair of chemistry at the school of chemistry, Edinburgh University and I’m a physical chemist or a chemical physicist. I’m particularly interested in studying the fundamental properties of molecules, how energy is transferred within them and also how we can make interesting nano devices out of carbon materials like carbon nanotubes and graphene.

Interviewer – Chris Smith

Eleanor, Phil Robinson who has written this feature in Chemistry World this month, he opens by saying, it’s three centuries since the University of Edinburgh appointed its first chemistry professor. Why is that significant?

Interviewee – Eleanor Campbell

Well, I think that’s significant, because this happened at a time when chemistry wasn’t recognized as an independent subject. Chemistry was a part of medicine and really Edinburgh was one of the first places to recognize the importance of chemistry and to study the basic fundamental chemistry as we know it today rather than seeing it as a tool for medics.

Interviewer – Chris Smith

You’ve got some pretty big name alumni too, haven’t you? I mean, no less, you have Professor Black, who discovered CO2.

Interviewee – Eleanor Campbell

That’s right, he wasn’t just an alumnus, he also came back as the chair of chemistry after a stint in Glasgow and he was actually very important in building up the chemistry education and the teaching.  So, he was not quite so research active when he came back but he put enormous efforts into building up the educational aspects.

Interviewer – Chris Smith

Do you think he was drowning in admin like many of his modern day counterparts?

Interviewee – Eleanor Campbell

Yeah, I kind of feel sympathy for him, when I read that his research activities declined somewhat. I don’t think the admin was nearly as bad as it is now, but actually there were other pressures of course and their salaries were very much dependant on the number of students that they taught.

Interviewer – Chris Smith

Really we have sort of come a full circle then, because now we’re charging students at least in England, exorbitant course fees to come to university?

Interviewee – Eleanor Campbell

Well that’s right, that’s right.

Interviewer – Chris Smith

So, historically that was the model?

Interviewee – Eleanor Campbell

Well, historically, the professor’s salary was dependant on the fees that the students paid, so it was even more critical.

Interviewer – Chris Smith

What impact do you think that had on what the professors actually did? Did that mean then that there was a huge temptation not to do any research because they were actually thinking ‘well if I do things that lots of people will sign up for…’ or was it just sufficient to have a big name and loads of people would work with you because then they’re going to get a job?

Interviewee – Eleanor Campbell

Well, I think in those days, there was quite an aspect of showmanship involved, there were a lot of public lectures and actually in the 18th century, in Edinburgh, the general public was signing up to attend lectures on Chemistry. Quite a remarkable number of people were doing this. So, I think the professors had to put a lot of effort into their lecturing, into their demonstrations and really building up an interest and enthusiasm among the general public. So, it’s not too different from what it is today but more critical from their personal family point of view perhaps, but this obviously would take away from research activities.

Interviewer – Chris Smith

I guess that chemistry was really the forerunner of cosmology that we have now making big waves in media isn’t it?. These days we use televisions and iPods to get the story out there and thing that people really find floats their boat is the universe and space science. When Michael Faraday was doing his stuff down at the Royal Institution and people like Black and Priestly and others were doing public lectures and exhibitions, it was really chemistry that was powering those.

Interviewee – Eleanor Campbell

That’s right, yeah. Well because there was no television obviously or animation or anything like that in those days and chemistry was very visible, you could do demonstrations, you could do interesting reactions, colour changes, all kinds of things happening which I think did capture the imagination of people.

Interviewer – Chris Smith

So, on its 300th anniversary, the University of Edinburgh has you at the helm of its chemistry department, what are you going to do to make your mark and what have you been doing to make your mark and what’s the department’s priorities now?

Interviewee – Eleanor Campbell

Well, I mean, constantly you are working on strategy to improve places and make the environment a very supportive and attractive one for excellent young chemists and support young chemists and this is something that my two predecessors have worked very hard to do and I’m continuing to do. In a way it’s slightly challenging, we’re in a very interesting elderly building, which was the first building on the King’s building site in Edinburgh, which was constructed in the early 1920s. So that brings interesting challenges which one wouldn’t have if one could work in a nice new flashy building that was specifically designed for this purpose.

Interviewer – Chris Smith

I was talking to some scientists in the States, in fact chemists at Duke recently and they said the best innovation to drive collaboration and drive research forward in the department was the provision of free coffee in an atrium in the building basement.

Interviewee – Eleanor Campbell

We don’t quite have free coffee.

Interviewer – Chris Smith

Oh, it’s Scotland after all, I mean nothing is free in Scotland.

Interviewee – Eleanor Campbell

Very, very inexpensive coffee

Interviewer – Chris Smith

Why am I not surprised?  But you could bear that in mind as a possible catalyst.

Interviewee – Eleanor Campbell

I’ve actually thought about it, I’m not sure that we did have free coffee for a while but we went, we did actually decide to charge a small token amount again. But yes, I think meeting places are an important aspect and getting a, you know, inducing a friendly collaborative open way of working is extremely important and that is something that I work hard to achieve. I think we have a happy place and also a place that encourages the young scientists which is very, very important and gives them a stepping stone to their career and help them  get off on a flying start.

Interviewer – Chris Smith

Eleanor Campbell from the University of Edinburgh.

(13:54 - A new technique that splits water but releases the oxygen and hydrogen in separate stages could allow for safer long term hydrogen storage - Split water splitting raises green hydrogen hopes)

Interviewer – Chris Smith

And staying in Scotland, scientists in Glasgow have come up with a way to store hydrogen but much more safely as protons, Andrew.

Interviewee – Andrew Turley

Splitting water is something you might want to do to get hydrogen, so hydrogen is very explosive and we can use it as a fuel and there’s a lot of excitement about the potential for a hydrogen economy where instead of using petroleum we use hydrogen.

Interviewer – Chris Smith

Problem is storing it, though, isn’t it?

Interviewee – Andrew Turley

Yes exactly. So as a gas it’s much harder to transport around the place than a liquid would be or a solid - gases take up huge volumes. Or if you want to take up very small volumes, you have to use a lot of energy to contain them.

Interviewer – Chris Smith

So, what is the potential solution here?

Interviewee – Andrew Turley

So Lee Cronin and Mark Symes at University of Glasgow have investigated the possibility of separating the splitting process into its two halves. Water is H2O, two hydrogens and one oxygen atom. When you put enough energy in, you can split that into hydrogen gas and oxygen gas and then the energy you put in can then be realized again when you combust it and it goes back to being water. So, can we do that in two stages and store the hydrogen as protons in some kind of holding pen, if you like, which in this case is a liquid, and then just produce the hydrogen at the last minute when you need it.

Interviewer – Chris Smith

Oh I see, so you’d put some energy in, you’d split the water molecule into oxygen which you could just let that go and then you put the hydrogen into some sort of state, where it’s not H2 gas, it’s actually stored as say hydrogen atoms or for want of a better phrase or hydrogen protons for simplicity terms and you then get those out again to turn them into hydrogen that you would then use to release energy from it later as though it would come out of a cylinder.

Interviewee – Andrew Turley

That’s right you use a phosphomolybdate anion to buffer the protons in solution and that’s the second half of the process, then when you finish the process off, finish that reaction off, you get the hydrogen having already dealt with the oxygen, a clear stream of oxygen earlier and actually what the researchers showed was that they could store it for eight months in that state. Now there’s a payback, in this it’s less efficient if you do the whole thing together, only 87% efficient.

Interviewer – Chris Smith

Do you think they can get the hydrogen away from the molybdate anion quickly enough because one of the big constrains here is, yes you can put the hydrogen in there, but you’re going to need the energy quite quickly if you want to run a car or some other technique, if it comes away really slowly, it might end up limiting the process.

Interviewee – Andrew Turley

This is very early stage stuff, so if you were to use this in a practical application, all sorts of elements of it would have to be optimized and really the storage is only part of the problem with the hydrogen economy. To go from the concept to practical applications, there’s a lot of things that still needs to be done.

Interviewer – Chris Smith

Very promising though, isn’t it?  Because we’ve obviously been grappling with this problem of what to do with the hydrogen for a really long time and this is the first real positive note I’ve heard about this in quite some time.

Interviewee – Andrew Turley

It is very promising yes, and hydrogen is very exciting way to use energy conveniently.

Interviewer – Chris Smith

 And cleanly.

Interviewee – Andrew Turley

And cleanly potentially.

Interviewer – Chris Smith

Thanks Andrew.

(17:24 - ‘Inverse vulcanisation’ can turn sulfur – a by-product of petroleum refining – into new and useful polymers - Radical approach to turn sulfur into polymers)

Interviewer – Chris Smith

And Bibi from hydrogen to sulfur and batteries.

Interviewee – Bibiana Campos-Seijo

Yes, we have news from a group of researchers at the University of Arizona in the US who have actually been able to utilize sulfur to generate new cathode materials for lithium sulfur batteries. They have created a new polymer that has a very high content of sulfur and also that is thermochemically stable and has really good properties, properties that can also be tuned by varying the amount of monomer that you add.

Interviewer – Chris Smith

Talk us through the process. Where do they get the sulfur from and what do they do with it?

Interviewee – Bibiana Campos-Seijo

Yes. Sulfur is a by-product of petroleum refineries, it’s a cheap and abundant resource.  And they have created a process that they have named inverse vulcanization. So basically what this involves is the better polymerization of monomers, the monomer is 1,3-deisopropenylbenzene.

Interviewer – Chris Smith

Easy for you to say

Interviewee – Bibiana Campos-Seijo

For simplicity we can call it DIB. They have used liquid sulfur as a solvent and as a reagent. Sulfur in elemental form is an 8-membered ring, when you melt it, it becomes a chain that has radical ends, so those tend to form polymers as well, but the problem with that is that they were unstable so they very easily depolymerise back into the monomer rings, but what they did, they actually used liquid molten sulfur as the solvent and the reactive for the reaction. So they found that it could directly copolymerize with DIB to form a very stable form of a sulfur copolymer and they didn’t need extra organic solvents, they didn’t need any initiator for the polymerization so really clean, really simple process with excellent properties for the objective which is lithium-sodium batteries.

Interviewer – Chris Smith

Bibiana Campos-Seijo. You’re listening to Chemistry World, sponsored by Waters with me Chris Smith. Still to come, a protective nano-suit for insects so they can be imaged alive under the electron microscope, and what is the significance of 400 parts per million. We’ll find out in a minute.

(19:52 - Doug Stephan tells us how the main group elements are back in vogue after years languishing behind more fashionable areas of research - Main group renaissance)

Interviewer – Chris Smith

But first to a chemical renaissance, that’s happening to a group of elements that are known as the main block elements, the boring things like carbon and boron that scientists had thought they had understood really well. But these chemical can pack, it turns out, some exciting punches with what’s going on in their p-orbitals and scientists are only now beginning to realize what they’d overlooked.

Interviewee – Doug Stephan

Hi, my name is Doug Stephan, I’m a Professor of Chemistry at the University of Toronto. The main group elements are a block of elements in the periodic table that include in the first row, nitrogen, oxygen and fluorine, boron and carbon as well, and then it also includes the elements below them in the periodic table, so that would be aluminium and silicon and phosphorus and sulfur so on. These are elements where the valence electrons are typically in the p-orbitals, so they have different reactivities than transition metals.

Interviewer – Chris Smith

Why are they interesting?

Interviewee – Doug Stephan

Well, the thing that makes them interesting to me is that a lot of the metals that people use are also very precious, so for example, things like rhodium and iridium are very important metals for catalytic processes but they’re also outrageously expensive. Let me give you an example, Rhodium is probably on the order of five times the price of gold. It’s very difficult to find and in contrast the main group elements are hugely abundant.  Silicon as an example, this most abundant element on earth. Silicon is found in sand, in glass and similarly with lot of the other elements, sulfur and phosphorus, nitrogen, boron these are much more common than some of the metals and they’re not as well used as some of the transition metals in performing important industrial processes.

Interviewer – Chris Smith

But if I had found a chemist like you in the 1980s and said ‘are these elements are interesting?’ You probably would’ve said ‘nah, we understand all of the chemistry of that, pretty well understood and they’re relatively boring’. Is it fair to say that they’re having a bit of a renaissance because we’ve begun to understand and discover some quite intriguing things about them?

Interviewee – Doug Stephan

Yes, you’re absolutely right. Up until 1990, into that era certainly there were people doing interesting things with main group elements, but it was very much from a fundamental point of view. What’s really happened in the last seven or eight years is that people have begun to look at reactivity and how we might use these elements in compounds to affect important reactions that might influence how we make materials that we might use.

Interviewer – Chris Smith

So, what changed in that period between the mid to late ‘80s and then 1990 onwards when people began to make these discoveries?

Interviewee – Doug Stephan

So, let me give you an example, when I was an undergraduate, this is  over 30 years ago, there was an experiment that we did, in which you would combine a boron compound, which is a Lewis acid which is an a electron acceptor and ammonia, then you would form a bond between nitrogen and boron because nitrogen has a pair of electrons that it can donate, so you form a B-N bond and people thought they understood it.  And then in about 2005 or so, we did some experiments in which we had the idea to look at exactly that very simple process, but changed the molecules so that the electron donor and the electron acceptor couldn’t get together, the other fragments of molecule around the boron and the nitrogen were large enough that it would stop the bond formation.  And when you do that what happens is you generate a situation where this is an incredibly reactive situation.  So, they would react with a variety of small molecules. And we’ve gone on to show that we could activate small molecules like hydrogen, ethylene, acetylenes and a whole variety of other organic molecules.  So, there’s a tremendous range of reactivity that we’ve been able to discover and other people have been prompted to look at their systems, that is to say what can we do in terms of reactivity? Are there ways we can look at these molecules differently so that we can deploy them in reactions that might be useful for us?

Interviewer – Chris Smith

So, what do you think this will give us that we couldn’t do before? You mentioned activating hydrogen and other small molecules but we have had ways of doing that. So, this doesn’t give us something we absolutely couldn’t do, does it?

Interviewee – Doug Stephan

No, you’re right that’s certainly true, but one thing that is very difficult to do is take an aromatic ring, that is like a molecule of benzene, to fully hydrogenate that molecule is very difficult, it takes very high energy, very high temperatures and a catalyst as well.

Interviewer – Chris Smith

So, this would be literally breaking into that delocalized of electrons and saturating it with hydrogens all over the place.

Interviewee – Doug Stephan

Yes, yes, we can do that under relatively mild conditions, about 100 degrees and we can do this with main group systems and this is something that is not known to be able to be done with simple transition metal compounds.

Interviewer – Chris Smith

And the other benefit of course is that they’re cheap, so unlike very exotic systems that rely on rare earths or other very, very unusual compounds, you’ve got these things at your disposal which we can effectively dig up out of the back garden.

Interviewee – Doug Stephan

Exactly, exactly. These are compounds that are readily accessible and at relatively low cost. This is I think what excites main group chemists at this point, is that we’ve seen this tip of the iceberg where we’re seeing reactivity that is industrially important where we see reactivity where that complements what we know about transition metal chemistry already and the ability of those systems to be catalysts. So, the question is, you know, what’s below the surface? What else is there that we will be able to do with these systems that we either can’t do with the transition metal or where we could replace a very costly transition metal with something much more common?

Interviewer – Chris Smith

Dough Stephan from the University of Toronto. And if you’d like to follow up on that item, there’s a really nice detailed feature on that story in the June issue of Chemistry World magazine. And now seeing insects as you’ve never seen them before, Emma.

(26:28 - Coating insect larvae with Tween-20, a common detergent, lets them survive the powerful vacuum inside an electron microscope - Polymer ‘nano-suit’ protects insects from vacuum)

Interviewee – Emma Stoye

Scientists have developed a ‘polymer nano-suit’, they’re calling it, that can protect insect larvae in the strong vacuum inside a scanning electron microscope. This is Takahiko Hariyama and colleagues at Hamamatsu School of Medicine in Japan and it was really, sort of an accident that they discovered this, because normally when you put anything alive in a scanning electron microscope, all you’d see is that all the water would evaporate and it would shrivel up and sort of crumble and die in a matter of minutes but they realized that if you put drosophila larvae, fruit fly larvae in the scanning electron microscope, they don’t do this, they stay alive and they’re happy and they wriggle around.

Interviewer – Chris Smith

Do they know why?

Interviewee – Emma Stoye

This is what they decided to investigate. they used a sort of a high-res image to zoom right in and they saw this very, very thin coating that had formed on the outside of the larvae and they reckoned it’s something to do with the extracellular substances they naturally secrete. They then turned off the beam of electrons and just had it in the vacuum chamber and it shrivelled up and died, so they then worked up from this that it was the electrons interacting with these extracellular substances, which was making this protective coating.

Interviewer – Chris Smith

Do they know which chemicals and do they know how the electrons are interacting with those chemicals to produce what must be effectively a sort of suit of armour really isn’t it?

Interviewee – Emma Stoye

Yeah, it’s like a space suit and they called it a nano-suit, it’s a very thin polymer, they think it makes, so they reckon that the electron beams provide these molecules with enough energy to form cross linkages and that’s what forms a polymer. They don’t know exactly what’s in there that is causing this to happen but they did look at the extracellular substances and realized that it was full of amphiphilic molecules so ones both hydrophobic and hydrophilic. And they then decided to look around to see if there’s anything else that they can get to do this, so they tried lot of  lab chemicals, detergents and soaps are amphiphilic as well and they found that Tween, Tween 20 which is a really common detergent used in labs did the same sort of thing. So when you bombarded that with electrons they formed this very thin polymer membrane and then they found that dipping other insect larvae, crustacean larvae, in Tween and then putting them in the scanning electron microscope protected them from dying which is what they’d normally do and they were able to produce fantastic high-res images of these things and then take them out an hour later and they grew and matured into adults and then they were fine.

Interviewer – Chris Smith

Amazing, could you use it for anything else because insects that’s very nice but if you’re not an entomologist, you’re instead a cell biologist for example or someone who wants to study other things could you use that trick elsewhere?

Interviewee – Emma Stoye

Well, that’s what they’re working on at the moment and I think that’s definitely the next step of the research because as you say it’s great to be able to see a super high-res video of a maggot wriggling around but not particularly useful in medical research, so I think what the really useful thing to do with this would be if you could do this with cells and tissues, you wouldn’t even need to keep them alive, if even they could just be kind of wet, so to speak, and not have to be desiccated and dried out and distorted in that way before you produce an image of them, that could be a significant advance in imaging.

Interviewer – Chris Smith

Thanks Emma.

(30:12 - What can we do with the waste created by burning biomass for energy? Convert it into useful porous silicates - Sieving silica sieves from biomass ash)

Interviewer – Chris Smith

Seeing things which are very small, silicates, tell us more Andrew

Interviewee – Andrew Turley

This story is all about what to do with biomass, specifically the waste from biomass, so you’ve been burning all this switchgrass and it produces a great deal of ash and it turns out you use them to produce mesoporous silica.

Interviewer – Chris Smith

What does that mean? Silicon with a few holes on it or something, I mean what’s a mesoporous silicate and why is this important?

Interviewee – Andrew Turley

Okay, so mesoporous means it’s got pores of 2 to 50 nanometres in diameter and that is very useful because it increases your surface area massively and silicate with this massive surface area can be used in all sorts of things.  So, catalysts are probably the most obvious use, but there’s uses in drug delivery as well and lots of other things.

Interviewer – Chris Smith                                                                                                                        

So, this is a way of getting silica out of ash but correct me if I’m wrong but silica is probably one of the most abundant chemicals in the Earth’s crust, so why do we need to get an ash to get it, why don’t we just go to the beach and get some sand?

Interviewee – Andrew Turley

That’s true. It’s very energy intensive - getting silicates out of naturally occurring silica, which is as you say sand you’d find on the beach and so this reduces that energy burden. What they use is the ash that’s collected in the flue pipes and this is very rich in silica so  yeah they’re able to dissolve that ash into a potassium hydroxide solution.

Interviewer – Chris Smith

So, you get this stuff out, what can you actually do with it then, I mean, why is this helpful, what can we use it for?

Interviewee – Andrew Turley

Mesoporous silica can be used in a wide range of applications, detergents for instance or cement and the key thing here is that you’re generating it from a waste product. Traditionally people haven’t really investigated biomass ash for that, they’ve looked at the organic part which is the carbon based elements. This is a different approach, we’re looking at the inorganic things and Duncan Maquarrie and his team at the University of York have shown you can do useful things with that inorganic part of the ash.

(32:29 - Trivia: Joseph Black of Edinburgh University discovered carbon dioxide on the 11th June 1754. In the last month, the amount of the gas in our atmosphere passed the milestone of 400 ppm.)

Interviewer – Chris Smith

Well, stay there Andrew because you can have the honour of delivering the trivia to bring us to the close this month. What have you got for us?

Interviewee – Andrew Turley

We’ve been talking about carbon dioxide for a long time, this is a huge problem - carbon dioxide in the atmosphere in increasing amounts, we’ve just reached something of a milestone, in that researchers  have shown that the average carbon dioxide in the atmosphere has now gone over 400 ppm consistently.

Interviewer – Chris Smith

Gosh, that’s a lot isn’t it? because I mean in the time we’ve been making the Chemistry World podcast, not today, obviously since we started this in 2006, it was 380 parts per million then, it’s gone up a lot.

Interviewee – Andrew Turley

It’s gone up a great deal and it would probably concern Joseph Black a great deal, who discovered carbon dioxide on the 11th of June 1754. He probably wouldn’t be able to imagine the scenario that we’re facing now.

Interviewer – Chris Smith

Of course when he was doing his experiments the level in the atmosphere would have been more like 280, so a long way short of where we are today.

Interviewee – Andrew Turley

Certainly. He wouldn’t have known that but it would have been a lot less back then and if you’d like to know more about Joseph Black and the chemistry department at the University of Edinburgh where he worked, we have a feature about it in the magazine this month.

Interviewer – Chris Smith

Thanks to Andrew Turley and also to the rest of the team, Bibiana Campos-Seijo and Emma Stoye. The Chemistry World podcast is sponsored by Waters - The World Leaders in Innovative Analytical Science Solutions and I’m Chris Smith from thenakedscientists.com. I’ll be back with more cutting edge chemistry next month. Until then though thanks for listening and good bye.

Subscribe to our podcasts

Subscribe in iTunes RSS feed Chemistry World Monthly podcast

Subscribe in iTunes RSS feed The Compounds weekly podcast


Related Content

Chemistry World Podcast – August 2011

1 August 2011 Podcast | Monthly

news image

Chemistry World Podcast – August 2011

Chemistry World podcast - June 2014

2 June 2014 Podcast | Monthly

news image

We speak to Tom Brown, the 2014 Chemistry World Entrepreneur of the Year, and find out why cells spend so much time doing not...

Most Read

UC Davis chemist sentenced to four years over explosion

19 November 2014 News and Analysis

news image

Postdoc sentenced over attempt to make explosive device and reckless disposal of hazardous waste

Grad student blamed for research misconduct at Utah

13 November 2014 News and Analysis

news image

Two papers have been retracted due to image falsification at the University of Utah

Most Commented

Beetle behind breath test for bank notes

17 November 2014 Research

news image

Photonic crystal inks inspired by longhorn beetle could help to fight counterfeiting

Bayer wins race to buy Merck & Co consumer care

9 May 2014 Business

news image

$14bn deal will make Aspirin inventor the number two over-the-counter healthcare company