Chemistry World Podcast - August 2009
00:12- Introduction
01:56-- Making hydrogen fuel from urine
05:05-- Cleaning up the dye industry
07:20-- Brian Merry on the search for the mechanisms of ageing
13:40 -- White phosphorus tamed
16:10-- Hybrid peptides trigger dramatic weight loss
18:16-- Graham Reed discusses the art of glassblowing
23:39 -- The tiniest droplet of acid
26:30-- Could sulphate particles accelerate global warming?
29:03-- The chemical conundrum - the Moon was most likely formed when the early Earth collided with another planet - but what data did NASA's Apollo astronauts collect to answer that question?
(Promo)
Brought to you by the Royal Society of Chemistry, this is the Chemistry World Podcast.
(End Promo)
(00:12 -- Introduction)
Interviewer - Chris Smith
Hello! This is August 2009's edition of the Chemistry World podcast with Bibiana Campos-Seijo, Matt Wilkinson and Nina Notman. In this month's show, why urine might be about to shoot up in value, at least as a fuel source.
Interviewee - Matt Wilkinson
Gerardine Botte of Ohio University has discovered a way of taking the urea from urine and turning that into hydrogen, we can use as a fuel. She has developed an electrolytic process that uses a nickel based cathode, which breaks the nitrogen - hydrogen bonds of the urea, which are much weaker than those of the hydrogen-oxygen bonds in water.
Interviewer - Chris Smith
That's Matt on the urea cat and he'll be telling us how that works in just a moment. Also on the way, keeping chemicals captive, for both their safety and ours.
Interviewee - Bibiana Campos-Seijo
The molecular cage is a self-assembly system and it basically encapsulates small hydrophobic molecules. So what the researchers realized was that white phosphorus was not only hydrophobic but also it has the perfect size and the perfect shape to fit within the cage because white phosphorus is tetrahedron, so it fits completely perfectly there.
Interviewer - Chris Smith
That's a new generation of molecular cages that can safely lock away things like phosphorus. Plus we'll be also be hearing how cutting down calories leads to longevity.
Interviewee - Brian Merry
Yes. On a chronic basis, if you feed an animal a smaller number of calories per day, you don't starve it, but if you restrict the energy intake, then you find that the animal will live remarkably longer or up to even 40% longer.
Interviewer - Chris Smith
Well, that's meaty stuff then and quite literally too. Hello! I'm Chris Smith. Welcome to Chemistry World.
(Promo)
The Chemistry World podcast is brought to you by the Royal Society of Chemistry. Look us up online at chemistryworld dot org.
(End Promo)
(01:56 -- Making hydrogen fuel from urine)
Interviewer - Chris Smith
First this month, you've heard of money going down the drain, but now read fuel too because scientists have a found a way to turn pee into H, tell us more Matt.
Interviewee - Matt Wilkinson
Well, Gerardine Botte of Ohio University has discovered a way of taking the urea from urine and turning that into hydrogen and we can use it as a fuel.
Interviewer - Chris Smith
How?
Interviewee - Matt Wilkinson
Well, she's developed an electrolytic process that uses a nickel-based cathode, which breaks the nitrogen - hydrogen bonds of the urea, which are much weaker than those of the hydrogen-oxygen bonds in water, which is the common way of trying to produce hydrogen electrolytically.
Interviewer - Chris Smith
So talk us through. You'd collect some urine or something with urea in it, you put some electrodes into this solution. I mean, how does this process actually work, in order to get the hydrogen off?
Interviewee - Matt Wilkinson
As you say, you take the urine, put some potassium hydroxide in the cell, you place a cathode and an anode -- the cathode is made from this special nickel-based 'whizzy' catalyst as they call it. You apply a voltage across the cell and this voltage only needs to be 0.37 volts rather than the 1.23 volts needs to electrolytically cleave water and what happens is at the cathode, the urea, binds to the nickel catalyst, the hydrogen-nitrogen bonds are broken, the hydrogen is released at the cathode and at the anode nitrogen is evolved and the carbon monoxide that's released is actually moped up by the potassium hydroxide and forms potassium carbonate.
Interviewer - Chris Smith
And this is energetically worth doing. In other words, the voltage you have to apply, the current, the energy you're putting in, it's worth doing that for the hydrogen that comes out?
Interviewee - Matt Wilkinson
I believe so. And even if it wasn't, there's actually a matter of public health here as well, because one of the biggest waste streams from humans is actually is our urine and this can then degrade by bacteria quite quickly into ammonia, which through various processes eventually gets released into the atmosphere and forms some particular pollutants such as ammonium sulphate and these then cause a myriad of health problems such as asthma, bronchitis, and even premature death.
Interviewer - Chris Smith
So, this is way you're advocating of solving that pollution problem, but at the same time getting something back. So would this be done locally, are you saying we would plumb something in our sewage works?
Interviewee - Matt Wilkinson
Well, actually, you'd probably want to do this locally, otherwise, if you did it at a sewage works, bacteria would have had chance to actually degrade the sample before hand and you'd already have released quite a lot of the particulate into the air, anyway. As per Logan, an expert in energy generation and wastewater at Pennsylvania State University says, it's a fantastic way of producing hydrogen. However, he does say that it's still a good idea to start saving up our urine and not quite, you have to remember about the P in pee and here he is talking about phosphorus. Globally, we need to start thinking about conserving phosphorus for use as fertilizer because just like oil, one day the deposits are all going to run out. We need to start building phosphorus recycling into our infrastructure.
Interviewer - Chris Smith
So, homemade hydrogen, perhaps. Thank you Matt.
(05:05 -- Cleaning up the dye industry)
Interviewer - Chris Smith
Now, Bibi talking about the question of waste and what to do with it, the dye industry is also having a problem.
Interviewee - Bibiana Campos-Seijo
Yes it is. It is a, sort of, environmental concern, especially in countries like China, where about 1.6 billion tons of dye containing waste water are produced every year.
Interviewer - Chris Smith
It's a lot.
Interviewee - Bibiana Campos-Seijo
It's a lot, yes and it is perhaps because of this reason that a team of Chinese researchers at the South-Central University for Nationalities in Wuhan have teamed up with a team from the US from the Colorado School of Mines and they have come up with a cheap and recyclable cleaning system.
Interviewer - Chris Smith
How does it work?
Interviewee - Bibiana Campos-Seijo
It involves metal oxides, basically, they have devised a system that has or that includes nickel oxide nanolayers that are only a few nanometres thin and basically they absorb the dyes like a sponge would, compared to the conventional methods which are up to now involved, using filtration with activated carbon. The regeneration of activated carbon is quite challenging and once used generally it is disposed off in landfills, so this seems like a really nice environmental method.
Interviewer - Chris Smith
So, once the dye has bound onto this surface, these nanosheets, what actually happens to the dye molecules, then how do you get them back or get them off and make sure they're not a, sort of, environmental problem?
Interviewee - Bibiana Campos-Seijo
Basically what you do is, you just destroy them by heating the system up, that suggests temperatures of about 500 degrees in just the normal oven and that destroys the dye molecules completely.
Interviewer - Chris Smith
But it doesn't damage your collection layer, your series of nanolayers that trap the particles.
Interviewee - Bibiana Campos-Seijo
It doesn't at all. It's completely reusable. They're doing the studies now on trying to determine how many cycles of absorption and desorption it can take and also what would be the best metals to use and although this research hasn't been published yet, they have submitted an article where they suggest that magnesium is even better than nickel at performing this cleaning of the waste water.
Interviewer - Chris Smith
So the dye industry is going greener. Thanks Bibi.
(07:20 -- Brian Merry on the search for the mechanisms of ageing)
Interviewer - Chris Smith
And now to an age-old question of well, why we get older? Brian Merry
Interviewee - Brian Merry
My work really has been to look at this complex problem by using an animal model, whereby we can retard the regular aging and the incidence of age-related disease and this is being called various names, being called diet restriction or calorie restriction when people thought that was the reason why diet affected the rate of ageing, food restriction. So it has many different names.
Interviewer - Chris Smith
But the bottom line is you feed someone less, you feed an animal less and it lives longer.
Interviewee - Brian Merry
Yes, on a chronic basis, if you feed an animal a smaller number of calories per day, you don't starve it, but if you restrict the energy intake, then you find that the animal will like remarkably longer up to even 40% longer.
Interviewer - Chris Smith
Cynics would say that regardless of whether it extends lifetime, it feels like you're living forever because you're so hungry all the time and life seems to go on forever, but what do you think the mechanism is that cutting down the calories actually leads to in order to prolong life?
Interviewee - Brian Merry
Well, again I have say, we're not certain about this. I mean, the model was first demonstrated in a mammal as early as 1935 to 1939 and people, I must say, are still working on it to try and work out what the underlying mechanisms are. Most popular one, one for which there is most evidence so far is the oxidative stress, or damage theory of ageing. But again, this controversy about this theory is that there are some items of data which just don't substantiate this theory.
Interviewer - Chris Smith
First would you tell us, what actually is that theory?
Interviewee - Brian Merry
The idea behind the theory is that as you use oxygen, to oxidize food stuff in cells to generate energy so an animal can live, a by-product of that is to produce what are called damaging free radicals, which can then interact with the DNA to produce oxidative damage or mutations that can damage proteins and they can damage lipids. Now there are a lot of defence mechanisms in cells to reduce these to harmless compounds such as water or to repair the damage, but not all of it can be repaired; not all of it can be removed from the cells and you get a slow accumulation of damage with in the cells, which impairs their efficiency and eventually leads to what we call aging.
Interviewer - Chris Smith
So, ironic to think that we actually are damaging ourselves through our metabolism.
Interviewee - Brian Merry
That's the idea, yes. The very fact that you use a very toxic element oxygen to maintain life is in itself damaging.
Interviewer - Chris Smith
Is it just because we don't have a choice about that? Why have we not evolved to have a better way of handling this very toxic stuff that we rely on for life?
Interviewee - Brian Merry
Well, because Natural Selection and evolution isn't directed towards to a particular aim, the reason that we can use the efficient process of oxidative phosphorylation, which is what mitochondria do when they use oxygen to extract energy from food stuffs, really it goes back to the fact that the first cells of our type, what are called eukaryotic cells, produce the symbiotic relationship of the bacteria which could use oxygen in its metabolism before we had a reductive environment and organisms didn't use oxygen until oxygen was produced by bacteria in sufficient quantities. And so we have this symbiotic relationship, the mitochondria cells were thought to originally to be free-living bacteria and through 3 billion years of evolution we've come together to be a symbiotic relationship.
Interviewer - Chris Smith
This is the proposal of Lynn Margulis, isn't it, who suggested the endosymbiont theory? But given what we now know about how mitochondria work, does this inform our understanding of why they produce these molecules and whether it's possible to stop them doing that?
Interviewee - Brian Merry
We can understand quite a bit about the bioenergetics, about how they produce these free radicals, but we can't stop them doing it and it wouldn't be a good idea to stop them doing it, because some of these free radicals at low doses are used in the signalling processes both with in and between cells, it's a dose relationship. A small amount of free radicals are a good thing; a large amount is a bad thing and that is difficult to control.
Interviewer - Chris Smith
Is it not possible, given that, you're saying that mitochondria come from bacteria or were bacteria once, that we have drugs that would target specifically bacteria, therefore could target mitochondria, is it not possible to deliver some drug that would soak up some of these harmful species and only do that at the site of mitochondrion to avoid precisely the problems we're signalling that you're talking about?
Interviewee - Brian Merry
Well, people have tried a whole range of antioxidants to try and soak up the free radicals. You don't want to interfere with the functioning of the mitochondria, otherwise you'll end up with no energy, you'll kill the organism, kill the cell, but people have tried to soak up the antioxidants, but without much success on survival profiles in mammals.
Interviewer - Chris Smith
So, what do you think that the big questions are then that people like you need to answer, in order to come with a pill which I going to be able to pop to keep me looking young and fresh as I do now?
Interviewee - Brian Merry
Well, that doesn't answer the question whether that would be a good idea, but I mean.
Interviewer - Chris Smith
Well, assuming people are less nefarious and better looking than me? What do you think the big questions are?
Interviewee - Brian Merry
I think, if we're go the pursue the oxidative stress that we understand quite a bit about how free radicals are produced from mitochondria, what is less certain is what is the target of these free radicals that actually determines the rate of ageing. We know that free radicals can cause a range of age-related disease and there's much more understanding about disease processes than about the actual rate of ageing. I think that's the big question at the moment. If this theory is to hold up what is the rate-limiting target that these free radicals are hitting?
Interviewer - Chris Smith
Let's hope they find out soon. That's Brian Merry, who works on the chemistry of the ageing processing at the University of Liverpool.
(Music)
Interviewer - Chris Smith
This is the Chemistry World podcast with me Chris Smith. And still to come, a way to combat weight gain and how many water molecules does it take to make an acid. The answer is 4 and we'll hear how German scientists have sussed that out in just a moment.
(13:40 -- White phosphorus tamed)
Interviewer - Chris Smith
But first, Bibi chemists have come up with a clever way to tame white phosphorus, P4.
Interviewee - Bibiana Campos-Seijo
Yeah, white phosphorus is a very nasty element and it's very difficult to keep under control, lets say. So Jonathan Nitschke from the University of Cambridge, in collaboration with researchers at the Universityof Jyvaskyla, in Finland, they have devised a method of actually storing it using molecular cages.
Interviewer - Chris Smith
Tell us the anatomy of the molecular cage, how does it work? What is it?
Interviewee - Bibiana Campos-Seijo
The molecular cage is a self-assembly system that uses iron ions held together by organic linkers and it basically encapsulates small hydrophobic molecules, so what the researchers realized was that white phosphorus was not only hydrophobic, but also it has the perfect size and the perfect shape to fit within the cage because white phosphorus is tetrahedron, so it fits completely perfectly there.
Interviewer - Chris Smith
So, how would you use these cages and how does the phosphorus get inside the cage if it then can't get out again?
Interviewee - Bibiana Campos-Seijo
Well, it can get out again, you can actually flood it out with benzene, it will push it out and occupy that space there and basically it just assembles like that in water, so you only have to have to phosphorus and then the organic framework or component and it really does assemble.
Interviewer - Chris Smith
So, you'd use this, say, someone had spilled some phosphorus, or you wanted a way of storing it safely, you add these molecular cages to the phosphorus, the phosphorus, P4 gets inside the cage and is therefore sequestered, why can't it if I dry it out just react with oxygen in the air anyway and catch fire like it normally does or poison somebody?
Interviewer - Bibiana Campos-Seijo
It doesn't react with oxygen because it such a perfect fit that oxygen is not allowed within that cavity and that stops the phosphorus from reacting, when if it actually were to react with the oxygen that would involve a change in volume and because the cage cannot accommodate that increase in volume, the phosphorus simply stays there for the next set of four months, so far.
Interviewer - Chris Smith
And how do the researchers say that this could actually be used?
Interviewer - Bibiana Campos-Seijo
Exactly, well, they talk about storage and clean up of spillages, so they're looking to use this, sort of, system for soaking up harmful chemicals from the environment, potentially in the future.
Interviewer - Chris Smith
Thank you, Bibi.
(16:10 -- Hybrid peptides trigger dramatic weight loss)
Interviewer - Chris Smith
Well, from one thing that's harmful, phosphorus to another that's very bad for you and that's eating too many cakes and pies and becoming fat. Nina, not that you're fat, what I am saying is that you may have a story about ways in which we might in the future be able to solve the problem out.
Interviewee - Nina Notman
Yes, US researchers have developed a synthetic peptide which has helped obese mice slim down. So this synthetic peptide simultaneously mimics the behaviour of two naturally occurring peptides and it caused some pretty amazing weight losses. So within one week of this peptide being injected, the mice have lost 25% of their body weight and 42% of their body fat.
Interviewer - Chris Smith
Well, that's quite a lot hell; they would presume that they were dead.
Interviewee - Nina Notman
No! Because the peptide was having combined effect to suppress their appetite and also allow them to burn more calories, so the peptide has key features from two naturally occurring hormones which are glucagon and glucagon-like peptide-1, so these are both known to suppress appetite, but generally they cause problems because glucagon increases our blood glucose level to dangerous levels and glucagon-like peptide1 decreases our blood glucose levels. So these researchers at Indiana University decided to find out what happened if you administered the two together. So, the peptide has key features that both fit these hormones and with a few tweaks they found out they had full potency both for the receptors.
Interviewer - Chris Smith
Well, I get it, you have a protein that looks in the same molecule like these two individual components, the glucagon and the glucagon-like peptide. So it does both jobs in one molecule and therefore you've got one thing offsetting the high blood sugar effect and another offsetting the appetite boosting effect and as a result you both burn more energy plus you eat less, so you lose weight.
Interviewee - Nina Notman
Exactly. So they're now looking to see if they can convert this into a human obesity treatment, but first up, they need to see if the mechanism is working in primates.
Interviewer - Chris Smith
Indeed, but of course the good news is that we have both of those hormone signals, working in us the same way they do in a mouse, which is kind of encouraging, because it suggests it should work.
Interviewee - Nina Notman
I certainly hope so.
Interviewer - Chris Smith
Then you'd be able to afford a few more pints and pie.
Interviewee - Nina Notman
Yeah.
Interviewer - Chris Smith
Thank you Nina. Nina Notman.
(18:16 -- Graham Reed discusses the art of glassblowing)
Interviewer - Chris Smith
And now to what's increasingly becoming a dying art. Glassblower now turned local counsellor, Graham Reed.
Interviewee - Graham Reed
Technically, the discipline of which I have so much experiences in scientific lab working and that is because we work with preformed glass tube or rod and occasionally sheet and we reform the glass using flames and mechanical devices like glassblowing lathe to turn big pieces of tubing and in reheating the glass we can then shape it by blowing the glass using a closed vessel with a single outlet or we can spin the glass centrifugally or we can slump the glass using gravity.
Interviewer - Chris Smith
So you're not one of these red cheeked blokes.
Interviewee - Graham Reed
Indeed no.
Interviewer - Chris Smith
Who had a lump of glass on the long tube?
Interviewee - Graham Reed
Absolutely not.
Interviewer - Chris Smith
It's the one thing that really defines the chemistry laboratory isn't it, these amazing intricate bits of glassware.
Interviewee - Graham Reed
Absolutely!
Interviewer - Chris Smith
How did you get into making those sorts of things in the first place?
Interviewee - Graham Reed
While at the school level, I was working as a science technician in one of the Union Carbide factories in Hampshire and my long-term interest in glass from my school boy days, when I used to play with the Bunsen burner and tubes in a local chemist's shop, I discovered there was a glassblowing factory or a glassblowing department in the Mullard Factory in Southampton and I did an entrepreneurship and since then I've been working in Australasia and England and Scotland over 30 odd years.
Interviewer - Chris Smith
And universities, pretty much universally, had someone with your sorts of skills in order to make their experiments possible.
Interviewee - Graham Reed
One stage what was then 44 universities in Britain, every university had a science department and invariably that meant a glassblower in the workshop, yes.
Interviewer - Chris Smith
And the most intriguing, difficult and intense bit of glassblowing you had to do?
Interviewee - Graham Reed
Triple-layered jacketed vessels are certainly a challenge. That's where you have a working vessel acting as a reactor, could be 2 litres, could be 5, 10 litres and then you have a jacket around it with water going between the two layers to cool it but in some cases, the chemistry requires working at cryogenic temperatures, may be down to -100 or -150 centigrade, in which a third layer is put around the glass and that then becomes the vacuum jacket to prevent condensation of atmospheric moisture.
Interviewer - Chris Smith
So, given that it took someone with your skill set to make that kind of apparatus, why are universities all over the UK not replacing people like you, when they retire?
Interviewee - Graham Reed
Largely, budgetary pressures within universities, the luxury of individual faculties having their own complete set of technicians has disappeared with the budgetary pressures and the effect has been to privatize the market place so that people who were university glassblowers have now effectively gone into self-employed business and then become subcontractors to the universities. And it's only the biggest universities with the biggest and the best science departments are still having the glassblowing persons.
Interviewer - Chris Smith
Doesn't sound very cost effective, but presumably, that's exactly what you did isn't it, because you set up your own operation.
Interviewee - Graham Reed
Absolutely yes! In 1998, I left Stirling University after 4 years of running a semi-commercial business where I was gaining enough income from outside work, to pay for my own salary and overheads, while still providing an internal service, but the university wanted the workshop space more than they wanted me and I was encouraged to leave and set up a subcontract business providing glassblowing to university and then working into the local business and science community.
Interviewer - Chris Smith
Is there a big demand, outside the university, for the kind of skills that you have?
Interviewee - Graham Reed
It's become increasingly more specialized and regionalized. In the period, I ran my own business, which I called Scotia Glass Technology. I had seven or eight school leavers come to me, two of those gents now run that business called Scott Glass, where they're carrying on the tradition of what I did up until around 2002.
Interviewer - Chris Smith
Who are the major customers though?
Interviewee - Graham Reed
Very much pharmaceutical based; the big names like GlaxoSmithKline, Zeneca and other such companies. The trouble with the market place is that these companies are often going through by outs and phoenix like regeneration, so the names keep changing, but the pharmaceutical industry with its very strong investment in drug research is probably there with the biggest budgets.
Interviewer - Chris Smith
So why have you exude glassblowing in favour of politics.
Interviewee - Graham Reed
Well, I decided to sell my business after 16 years, partly because of almost mental exhaustion, although in between I was busy doing a degree in politics and a number of social activities, but I got to the point where I wanted a change and when I sold the business, I actually invested in Micro Wind Renewable Energy and acted as a consultant for a company for about 6 or 7 years. Ending up in politics was really as much a fact that the proportional representation in Scotland has given, minor parties a bigger say in local government.
Interviewer - Chris Smith
From reaction vessel maker to political reaction read. That was Graham Reed, recounting his experience of professional glassblowing.
(23:39 -- The tiniest droplet of acid)
Interviewer - Chris Smith
And now to an incredible feat of chemistry in which scientists have answered a fundamental question about the behaviour of acids. So Matt, tell us more.
Interviewee - Matt Wilkinson
Well, basically what they've done is they found the smallest number of water molecules needed to disassociate the hydrogen and the chloride, so that the strongest HCl droplet that you could ever find, the most acidic HCl droplet you can ever make and actually all it takes is four water molecules.
Interviewer - Chris Smith
So what we're getting at here is you have HCl, hydrogen chloride when you put that near water, it ionizes, it turns into H+ and CO- that's why its acidic, but the big question is, well how many water molecules is it going to take in order to stabilize that and you're saying just four?
Interviewee - Matt Wilkinson
Yeah.
Interviewer - Chris Smith
Per molecule of HCl.
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