Chemistry World Podcast - March 2010
00:12 - Introduction
01:47 - Male fertility exam at home
04:07 - Cancer risk from 'third-hand smoke'
07:20 - Mark Korsmit from paint company AkzoNobel discusses paint used on McLaren Mercedes 2010 Formula 1 car
14:00 - How spider silk soaks up water
16:30 - Closure on a knotty problem
19:58 - Hydrogen podcast from our weekly Chemistry in its element podcast series
26:18 - Decades-old meteorite gets holistic treatment
29:46 - Better batteries with nano-cables
(Promo)
Brought to you by the Royal Society of Chemistry, this is the Chemistry World Podcast.
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Interviewer - Chris Smith
This month, the walls have ears, but do they also have lungs?
Interviewee - Bibiana Campos-Seijo
Nicotine residues from smoking have been observed in household surfaces and the concern here is that they'll further react with compounds from the environment at home; gases like nitrogen dioxide are now known to react with the nicotine residues and produce carcinogenic compounds
Interviewer - Chris Smith
Bibiana Campos-Seijo looks at the evidence for third hand smoke carcinogens oozing out of the wallpaper. Also, how spider silk could hold the nanoscale key to water collection, what a pristine meteorite is revealing about the origins of the solar system and painting the town red with McLaren.
Interviewee - Mark Korsmit
A formula one car's is produced once and then used throughout the season. The body itself changes as the season progresses and that means constant changing of panels, etc and they need to be painted. So, if you're able to deliver paints that cures faster, it allows the engineers to have more time for finalizing the designs and getting them to race track
Interviewer - Chris Smith
And you can hear Mark Korsmit explaining how new paints are helping formula one to go faster later in the program. Hello! I'm Chris Smith and also in this the March edition of the Chemistry World podcast are Bibiana Campos-Seijo, Nina Notman and Phil Broadwith.
(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)
Interviewer - Chris Smith
First up this month, home sperm counting - sounds intriguing. Phil tell us more.
Interviewee - Phillip Broadwith
Absolutely Chris. Well, one of the major problems that affects couples trying to have children and failing is the possibility that the man's sperm isn't possibly as effective as it ought to be and one of the things that might be wrong is that they're just aren't enough of them, so they need to be counted. At the moment, what happens is that you have to take your sample to a hospital, where a technician in a lab sits down with a microscope and physically counts the sperm. But obviously that's less than ideal. You've got to get your sample to the hospital relatively quickly and there's a level of human error. You've got to start manhandling the samples and whatever. So, it's not ideal.
Interviewer - Chris Smith
Okay those are constraints in mind, what's solution.
Interviewee - Phillip Broadwith
Well, Loes Segerink at the University of Twente in the Netherlands thinks that the solution is to have an automated microfluidic device and that's exactly what she has come up with.
Interviewer - Chris Smith
Talk us through it.
Interviewee - Phillip Broadwith
Your sample of sperm is mixed with some polystyrene beads and then passed through a microfluidic channel which detects the electrical impedance of the solution that's going past it and each kind of cell has a particular signal associated with it as do the polystyrene beads. Polystyrene beads with a known concentration within the sample, therefore if you compare the count of beads to sperm, you can get a concentration of the sperm.
Interviewer - Chris Smith
And this is much quicker and presumably more reproducible than using a person to do that job?
Interviewee - Phillip Broadwith
Yeah, absolutely and it doesn't involve having to take your sample to a specialised lab. So I mean, if you really want to do, you can have one at home or more realistically, we're talking about may be at a doctors surgery.
Interviewer - Chris Smith
When you say, have this at home, are they actually in a position where this is a device that could be rolled out tomorrow or is there still lots of development to do?
Interviewee - Phillip Broadwith
No, they're still at the sort of prototyping stage. Obviously, there would have to be some way of getting the human sample of sperm into the device.
Interviewer - Chris Smith
Some people are good, ain't Phil.
Interviewee - Phillip Broadwith
Yes, because we can't count on that. So, we need a slightly more reliable mechanism for getting it in there.
Interviewer - Chris Smith
Okay. Well, we'll see how that turns out because it will be interesting too when they actually start trying it, whether it does bear fruit. Anyway, thank you Phil.
Interviewer - Chris Smith
Bibi, assuming that someone doesn't have a low sperm count and they do have some children, we're all taught about the risk of second hand smoke, but there's this new concept that you're saying is third hand smoke. Tell us about this.
Interviewee - Bibiana Campos-Seijo
Yes, this new term has been coined to describe nicotine residues that deposit on household surfaces.
Interviewer - Chris Smith
Nicotine?
Interviewee - Bibiana Campos-Seijo
Yes, nicotine residues from smoking have been observed in household surfaces and the concern here is that they further react with compounds from the environment at home. Gases like nitrous acid or nitrogen dioxide are now known to react with the nicotine residues and produce carcinogenic compounds.
Interviewer - Chris Smith
So let me just check if I've got this straight in my mind. The person smokes a cigarette. The materials that the cigarette produces, they breathe out into the air. They deposit on wall surfaces and other surfaces. They then come back off the surfaces at a different rate and react with chemicals in the air to produce things that can cause cancer.
Interviewee - Bibiana Campos-Seijo
Absolutely, that's exactly what happens. This group of researchers at the Lawrence Berkeley National Lab in California experimented in a truck. Actually they used some cellulose inside a truck that was driven by a smoker and they monitored the cellulose for three days. They took it the lab and they found that three carcinogenic compounds had been produced as a consequence of the reaction that I was talking about. Two of them had already been found in tobacco smoke, but the third one is one that is not usually present in tobacco smoke and toxicological studies are needed.
Interviewer - Chris Smith
Do you know, what's really worried me about this though, is that you know, parents are pretty clued up, if you say to them, you're having some young children or you got some young children, don't smoke around them. They'll say yes I don't, but I still smoke, I get outside. So, this presumably means they're going to come in with that smoke material still on their clothes perhaps even on their hair and then presumably they'll just exude that into the air and they'll make those chemicals in the air in their house. So, even though they've taken the main body of the smoke outside, there's still the effect going indoors when they come back.
Interviewee - Bibiana Campos-Seijo
Obviously, in the case of clothes or hair, you will obviously wash it frequently, but if you're talking about wallpaper for example, you can have children exposed for a weeks or even months. So it is a concern for sure. What hasn't been determined yet is how much of a concern it is. Interviewer - Chris Smith Indeed. I was going to say, its one thing to show this can happen when you're using very sensitive pieces of equipment, its another to prove it has a clinically relevant effect, isn't it that there's enough of this being produced to then trigger disease relative to all the other things we're being exposed to.
Interviewee - Bibiana Campos-Seijo
Absolutely.
Interviewer - Chris Smith
In the environment.
Interviewee - Bibiana Campos-Seijo
Yeah, absolutely. At the moment what they have shown is the chemistry and then the next step would be to see how much exposure it generates. One of the concerns obviously with children is that they interact very differently from adults with their environment and it has estimated that their exposure could be 20 times higher than adults. So it is a concern, but we need to wait and see.
Interviewer - Chris Smith
So, if the walls are yellow, probably worth giving the room a miss. Thank you Bibi.
Interviewer - Chris Smith
Now, how do you paint a Formula 1 car? Answer, quickly. Mark Korsmit.
Interviewee - Mark Korsmit
So in the past, paints is often being used for protection in aesthetics to maintain gloss for centuries and the secondly it's about 200-years-old, so that's where it's derived from. However, you see more and more, their performance is being used as a field for development for paints, especially Formula 1 is critical. First and foremost, it's a substrate. These are not regular substrate or steel, aluminum etc, used on cars, but more the modern materials, composites and carbon. Besides that, the paint has to endure tremendous heat, vibration, battering by stones etc, from the track. On top of that, you also have to bear in mind that performance can be enhanced by using specific types of paints, but next to that a formula one car is well produced once and then used through out the season, but what you see is that the body itself changes as the season progresses and that means constant changing of panels, etc and they need to be painted. So, if you're able to deliver paint that cures faster than previous, it allows the engineers to have more time for finalising the designs and getting them to the racetrack.
Interviewer - Chris Smith
For someone who probably spent far too much time eroding brain cells, by being exposed to these kinds of things, when I was a bit younger. Could you just explain when you put with the spray gun onto a surface, chemically speaking, what is actually going on?
Interviewee - Mark Korsmit
Basically, paint is consisting of a system. You start with a primer, for making sure there's a good bond and also a flat surface. After that, we apply a chrome, so that's the actual chrome look that you see and that's basically colour, but then a very special pigment because if there's too much resin in there, then you get a dull silver-like look, so then it will be polished and it really looks like high chrome and that's just for the effect. We finish it off with a clear coat which is a varnish and it's a two component product and that is actually the product that ensures the colour remains throughout the reason, but it also provides protection for rain, for UV light, stone chips etc. So, basically it's a three-stage system.
Interviewer - Chris Smith
In the old days, we used to be able to get away with putting just about anything in paints, as long as it looked good. These days, the European Union are not so happy about that, nor are the people who have to spray these things on. So how has this industry had to respond to changing regulation and changes in the rules about which chemicals you can and can't use?
Interviewee - Mark Korsmit
In the industry of coating, there's constant evolution and every now and then some revolution, but what you see that certain pigments are being restricted like lead-containing pigments and you see that happening throughout the industry on a constant pace. So AkzoNobel is continuously screening their raw materials for suspect materials and when materials are suspects they are not restricted; we will try to minimize the use of it or even replace with new alternatives, this is one of the key areas. On the chemist though, if it's on a molecule base, there is specific restrictions in place. First and foremost, its VOC emissions or the compounds of volatile organic compounds, you've seen in the past it could contain about 800 grams, 900 grams per litre. However, we're utilizing new technology, reducing the VOC compounds to 420 grams per litre maximum for a base coat and a varnish. The primer could be up to 540 grams and that is a significant reduction from what it was in the past and we use for example, water-bond technology for that. But you see the environment being managed also on another area. We're now using a new drying method and that is revolutionary in combination with paints and that reduces the CO2 emission with about 80%. Why CO2 emission, because the normal curing process of paint is by heating it up, so you heat the environment, the object up and that obviously is normally using natural gas and we've changed that system with McLaren. So therefore the CO2 emission caused by this heating up, which is significant, is reduced by 80%.
Interviewer - Chris Smith
You mentioned that performance is important; obviously it's important in formula one.
Interviewee - Mark Korsmit
Yes.
Interviewer - Chris Smith
Fractions of a second determine who wins and who loses, but also given the number of miles that the average car is driving on the road, if you can get paint that is going to give slightly less air resistance, that presumably is going to translate into a huge environmental saving?
Interviewee - Mark Korsmit
Exactly, so every small bit will contribute, although I must say that the Formula 1 environment is so different than from the normal conditions of our car, you have to think about exposure, formula one car last maximum for one season, whilst the cars that you and I drive have to last for 10-20 years and the paints from ours has got a lifetime warranty. So then if you talk about air resistance in these kinds of areas, we can make a sacrifice for formula one, a sacrifice, which we're not likely to be able to do so on a normal car, but also the speed generated and air resistance has got a strict relation with the speeds and object drives and you can imagine that 300 kilometres now on a track is a little bit different than we can do on a motor way. We utilize this technology also in our marine protective business unit, where we, for example apply it to the hull of a ship and because it's such low friction, it reduces drag of the ship and saves up significant amounts of fuel consumption and I heard the number between 6 and 7% is feasible.
Interviewer - Chris Smith
Which of course is going to translate into a reduction in carbon emissions and things? Do you get to drive the F1 car?
Interviewee - Mark Korsmit
No, the dream is still alive.
Interviewer - Chris Smith
Well, as they say, you can but dream. That was Mark Korsmit, he's from the Dutch Paint Specialists AkzoNobel.
Interviewer - Chris Smith
This is the Chemistry World with me Chris Smith. Still to come, how scientists are tying molecules a knot and a revolutionary new battery design, but first Nina, now not everyone likes them, but spider silk definitely likes water. Tell us more.
Interviewee - Nina Notman
So Chinese scientists from the Chinese Academy Of Scientists in Beijing have been looking how the spider silk captured the morning dew and they published this work in the journal, Nature. So when they went to find out how nature worked, they also wanted to use the information to make artificial materials to capture water from air. So they've been looking at the hackled orb-weaver spider webs using a scanning electron microscope and they found that the dry thread has loose hydrophilic puffs of very fine silk, in particular places along its length and when the web is exposed to water vapour, that's when changes occur, so these puffs shrink and become rough, then form knots and as the water kind of settles onto the web, it slides along the smooth silk and accumulates into the rough knot, so this is where the big droplets of water appear.
Interviewer - Chris Smith
It's fascinating because that's saying basically a spider web is not a homogeneous structure along the length of each thread, there are these knots separated by these thin slippery bits, which is why you get the water collecting in these blobs.
Interviewee - Nina Notman
Yes. That's these scientists have seen, yes.
Interviewer - Chris Smith
Do they think that this has got some kind of application or industrial application, or is this purely just an academic interest?
Interviewee - Nina Notman
Yeah, they think industrially it could be useful for any kind of application, where you'd want to collect water from air and also from a chemistry point of view they could be used as filters to draw substances after chemical reactions.
Interviewer - Chris Smith
If you wanted to do that how would you do it?
Interviewee - Nina Notman
For having looking at the natural material, they've now been trying to make artificial materials. So they've made an artificial spider silk of nylon fibres and coated it with polymers and they've looked at the structures and this again under the microscope and they've found that when it is dry there are these really tiny knots and when it is exposed to mist, it behaves in a very similar material to the natural ones.
Interviewer - Chris Smith
And that presumably collects water?
Interviewee - Nina Notman
Yeah. And collects water in the same ways, so they found that initially random droplets appear on the surface and these kind of the droplets slide along the artificial body silk to form the bigger droplet in the knot area.
Interviewer - Chris Smith
So presumably then we're talking rain catching machines, mist filters to get water in areas where there isn't much rain there?
Interviewee - Nina Notman
Hopefully so, yeah.
Interviewer - Chris Smith
Do we know why the spiders do it though?
Interviewee - Nina Notman
We don't know why the spiders do it, because normally when people are looking at spider silk, they're considering its extreme strength and people haven't looked into this before.
Interviewer - Chris Smith
So, I guess from one knotty issue, knots in spider webs from Nina Notman to another knotty problem is you're tying molecules in knots, Phil tell us about this.
Interviewee - Phillip Broadwith
Yes Chris. You'd really struggle to see these kinds of knots with an electron microscope; we'd need something a lot more powerful. We're talking about single molecules that are tied up into a true knot and if you want to know what a true knot is, go and ask a mathematician, but be sure to have a pillow handy because it might be a lengthy explanation, basically it comes down to the fact that to be a true knot, you have to have all of the ends tied up together. You can't unravel a knot.
Interviewer - Chris Smith
So shoe lace, a knot in a shoe. That's not a true knot then?
Interviewee - Phillip Broadwith
Absolutely not. No.
Interviewer - Chris Smith
So what have they done to do this chemically?
Interviewee - Phillip Broadwidth
Okay, what Chris Hunter and his group at Sheffield in the UK have done is take a long stringy molecule, which has three sides that combined to a metal. When you add zinc to that, you get two of the metal binding sides, make loops out of sort of in the middle bit of the string, but then for the third one to get into position to bind it has to physically thread through the loop. So you then end up with what's called an open knot. So, the molecules has been tied up a little bit, but it still has the ends free.
Interviewer - Chris Smith
So that doesn't' fulfil the criteria then? Does it? It's got the ends free. So what do you then?
Interviewee - Phillip Broadwith
So that's where the next stage of the chemistry comes in. You got to try and tie those knots together. First of all, they tried using an ester bond, but the problem with that was what you really wanted to do is be able to get the metal out of the middle, when they tried to use chloride or lithium sulfide to get the metal out, it either just did nothing or it broke the ester bond. So what the group then did was to use alkene metathesis to close the loops instead. So you then have a true trefoil knot, which is a little bit like the sort of Celtic knots that you see. It's a very simplified form of that.
Interviewer - Chris Smith
Beautiful. But what can you actually do with it?
Interviewee - Phillip Broadwith
Molecular knots are very interesting from the point of view of comparing them with things that happen in nature. There are certain proteins which are naturally knotted up, but they tend to be mostly open knots. The other thing to thinks about what these knots is that they're handed, they're chiral so if you can make a knot structure, which is itself chiral and then you can decorate it with various other bits to do kind of catalytic chemistry or whatever, you can end up with a very rigid and very spatially defined catalyst which should hopefully give you some interesting catalytic activity.
Interviewer - Chris Smith
And just for the sake of argument, how big are these knots?
Interviewee - Phillip Broadwith
Well, if you're comparing them to say a drug molecule that are a bit bigger than that because you have to have enough length to kind of fold up on itself, but they're nowhere near the size of a protein molecule for example. We're talking a relatively short polymer chain.
Interviewer - Chris Smith
And given how hard they're to make, are we close to actually being able to make them in a viable way or is this just someone saying we can do this, but its going to be a little while before we can do anything useful with it?
Interviewee - Phillip Broadwidth
Yeah, I mean, this kind of research is still very much at the early stages. People are still exploring what shapes we can make, whether we can make knots even more complex than this kind of very simple trefoil knot. So, yeah, we're still at very early stages and any kind of application is going to be a little way off. Because first of all, you've got to be able to make one hand of the knot rather than the other, so that's another problem entirely.
Interviewer - Chris Smith
So they've got the knot sorted. Now researchers just need the nano bow tie to practice on. Thank you Phil. And now, here's Meera Senthilingam, with news of another chemical offering from Chemistry World.
Interviewer - Meera Senthilingam
Each week, the Chemistry in its eement podcasts bring you the tales, trials and tribulations behind the discovery and chemistry of the elements in our periodic table. So to you give a taster of what these podcasts reveal, I thought it best to share the element that some consider to be, the king of the elements. Well, that's Brian Clegg's view at least.
Interviewee - Brian Clegg
Forget 10 Downing Street or 1600 Pennsylvania Avenue, the most prestigious address in the Universe is number one in the periodic table, Hydrogen. In science, simplicity and beauty are often equated and that makes hydrogen as beautiful as they come; a single proton and a lone electron making the most compact element in existence. Hydrogen has been around since atoms first formed in the residue of the Big Bang. It is the most abundant element by far. Despite billions of years of countless stars fusing hydrogen into helium, it still makes up 75% of the detectable content of the universe. This light colourless, highly flammable gas carries on its uniqueness by having the only named isotopes and some of the best known at that deuterium with an added neutron in the nucleus and tritium with two neutrons. Hydrogen is essential for life in the universe and just about everything. Without hydrogen we wouldn't have the sun to give us heat and light. There would be no useful organic compounds to form the building blocks of life and that most essential substance for life's existence, water would not exist. It's only thanks to a special trick of hydrogen's that we can use water at all. Hydrogen forms weak bonds between molecules latching onto adjacent oxygen, nitrogen or fluorine atoms. It's these hydrogen bond that gives water many of its properties. If they didn't exist, the boiling point of water will be below minus 70 degrees Celsius. Liquid water would not feature on the earth. Hydrogen was the unwitting discovery of Paracelsus, the 16th century Swiss alchemist also known as Theophrastus Phillippus Aureolus Bombastus von Hohenheim. He found that something flammable bubbled off metals that were dropped into strong acids, unaware of the chemical reaction that was forming metal salts and releasing hydrogen. However, the first person to realize hydrogen was a unique substance, one he called inflammable air was Henry Cavendish, the Nobel ancestor of William Cavendish, who later gave his name to what would become the world's most famous physics laboratory in Cambridge. Between the 1760s and 1780s, Henry not only isolated hydrogen, but found that when it burnt it combined with oxygen or dephlogisticated air as it was called to produce water. These clumsy terms was swept aside by the French chemist Antoine Lavoisier who changed chemical naming for good, calling the inflammable air, hydrogen, the gene or creator or hydro - water. Because hydrogen is so light, the pure element isn't commonly found on the earth. It would just float away. The prime components of the air, nitrogen and oxygen are 4 and 16 times heavier, giving hydrogen dramatic buoyancy. This lightness of hydrogen made it a natural for one of its first practical uses, filling balloons. Neon balloons soar as well as a hydrogen balloon. The first such airy vessel was the creation of French scientists, Jacques Charles in 1783, who was inspired by the Montgolfier brothers' hot air success a couple of months before to use hydrogen in a balloon of silk impregnated with rubber. Hydrogen seemed to have a guaranteed future in flying machines, reinforced by the invention of air ships built on a rigid frame called dirigibles in the UK, but better known by their German nick name of Zeppelins, after their enthusiastic promoter, Graf Ferdinand von Zeppelin. These air ships were soon the lioness of the sky, carrying passengers safely and smoothly across the Atlantic. But despite the ultimate lightness of hydrogen, it has another property that killed off air ships. Hydrogen is highly flammable. The destruction of the vast Zeppelin, the Hindenburg, caused by a fire probably from static electricity was seen on film by shocked audiences around the world. The hydrogen air ship was doomed. Yet hydrogen has remained a player in the field of transport because of the raw efficiency of its combustion. Many of NASA's rockets including the second and third stages of the Apollo programs Saturn V and the space shuttle's main engines are powered by burning liquid hydrogen with pure oxygen. More recently still, hydrogen has been proposed as a replacement for fossil fuels in cars. Here it has a big advantage over petrol of burning to provide only water, no greenhouse gases are emitted. The most likely way to employ hydrogen is not to burn it explosively, but to use it in a fuel cell, where an electrochemical reaction is used to produce electricity to power the vehicle. But even if we don't get the hydrogen fuelled cars, hydrogen still has a future in a more dramatic energy source, nuclear fusion, the power source of the sun. Fusion power stations are tens of years away from being practical, but hold out the hope clean plentiful energy. However, we use hydrogen though; we can't take away its prime position. It is numero uno, the king of elements. Interviewee - Meera Senthilingam Elemental royalty there, brought to you by science writer, Brian Clegg. And you can hear more stories about the discovery and reactivity of the remaining elements as the well the scientists behind them, by visiting the web site at rsc dot org forward slash chemistryworld forward slash podcast forward slash element.
Interviewer - Chris Smith
Meera Senthilingam. And you can also track down Chemistry in its element as a podcast on iTunes. In just a moment, how some carbon nanotubes and a bit of titanium dioxide looks at to revolutionise lithium based batteries. But first Bibi something that's out of this world!
Interviewee - Bibiana Campos-Seijo
Right, this story is about meteoroid getting a holistic treatment.
Interviewer - Chris Smith
What are the kinds of treatments can meteorites get then?
Interviewee - Bibiana Campos-Seijo
This one has had a lot of probing and testing actually. It was discovered at the end of the 1960s in Australia and at the time, the analytical chemist that were dealing with it and tried to get some data out of it, were using all the technology that was at their disposal to try to get some information about it generally biologically active components to see if they could actually shed any light into the potential sources of life on earth. So they were..
Interviewer - Chris Smith
What age was the meteorite then?
Interviewee - Bibiana Campos-Seijo
It is at least old or of the same age of the sun.
Interviewer - Chris Smith
So born from the same primordial soup that's born our solar system basically. So therefore things that are in it gave rise us to as well ultimately.
Interviewee - Bibiana Campos-Seijo
Absolutely, the intention was to obtain information that would help us understand what was happening at those very early stages of the solar system, specifically looking at the chemistry that operated at or just before the birth of our solar system. So this meteorite would be very useful to analyse because of all the information that could be locked in. At the time they were using a very targeted approach which involved searching for a specific group of chemicals such as amino acids, but the analyses that is being carried out at the moment by a group of researchers at the Helmholtz Center at Munich in Germany is a non-targeted approach. So basically what they've done is to have use a new technology that has a very interesting name.
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