20 posts tagged “last word”
Published in Chemistry in Britain, (edited a bit to make it more PC) June 2000 (CHEMTECH wouldn't take it, but I've tagged it "last word" anyway).
Not long ago one of my development projects took me to a ceramics manufacturer near the Rhine. I was delighted to visit their laboratory, for it was as though I had stepped back a generation – Bunsen burners, tripods, crucibles, pipe clay triangles, the works. At first I thought that they were either extremely conservative, or else they were keeping the laboratory as a sort of museum. But then it dawned on me that for the ceramics industry this is all still perfectly appropriate technology.
Shortly afterwards business took me to Heidelberg. Strolling through the University I asked my guide about famous chemistry alumni. Well, Gmelin had been there and Mendeleev, but the best known name was Bunsen. Very much a chemist of the old school, he had nearly killed himself accidently by arsenic poisoning, and had lost an eye in an explosion. My guide hadn’t seen a Bunsen burner in decades, so I was pleased to be able to tell him that some laboratories still used them.
That evening, over the Schloss, there was an impressive fireworks display. A change in wind direction and I could smell the smell of ignited gunpowder. Together with thoughts of Robert Bunsen’s career, the flashes and bangs and the mildly sulphurous aroma reminded me of what had attracted me to chemistry in the first place. Stink bombs, home made pyrotechnics, acid burns, wrecking my mum’s kitchen with potassium permanganate.
Returning home, I attended a conference on the declining number of pupils electing to study chemistry after age sixteen. Great efforts have been made to attract more girls to the subject, with considerable success, but this has been accompanied by an even bigger fall off in the number of boys donning the lab coat. The reason is not hard to fathom.
The chemical industry and chemical education have improved their safety records enormously in the thirty odd years since I first opened a chemistry set, or thrilled to the stinks and bangs and roaring blue flames in the school laboratory, or stole a few inches of magnesium ribbon for home combustion. It would no longer be ethical to teach teenage children how to generate toxic gases, or form explosive mixtures of hydrogen or natural gas with air, and provide them with the means to do so. Unfortunately, in sanitising our subject and de-emphasising the macho side we have thrown away much of the excitement for adolescent males.
We need to regenerate enthusiasm amongst the little horrors, and recognise that we may have made the subject too “girly”. Educationalists are coming round to the idea that boys and girls respond better to different teaching approaches. Nowhere is this more true than in chemistry. We could almost use two separate curricula. Boys need their fumes and their explosions. We can’t go back to letting them play unsupervised with the Kipps apparatus, or having them generate acetylene and chlorine in the same boiling tube on the open bench, so what do we do?
I suggest that the “bangs” shouldn’t be too difficult to handle. TV, video and the Internet can play very useful roles, but even better would be a series of lecture demonstrations, probably in university lecture theatres and compulsory for all thirteen year-old boys, on the chemistry of explosions. The “stinks” would be a bit trickier, but the technology is coming. We need to produce a set of scratch and sniff cards covering all the smells that used to be so important to chemists – hydrogen sulphide, sulphur dioxide, acetamide, even benzene and chloroform. If the necessary concentrations are too high for safety then we must learn how to artificially stimulate the olfactory sensors to mimic these important odours.
More seriously, and forgetting the sex differences for a moment, I strongly believe that we industrialists could also do much more, in terms of giving talks to schools, letting classes visit our facilities, providing more summer placements to sixteen year olds. As schools chemistry becomes less hands on it is important to demonstrate how what they are learning is linked to the real world.
But to get back to Bunsen, I’ve been reading up about his career recently. He didn’t really invent the burner that bears his name, but he was very interested in flames and he did make some critical contributions to the development of spectroscopy. And he discovered the joy of burning magnesium ribbon. My hero.
Published in Chemistry in Britain, August 1998 (tagged "last word" even though CHEMTECH didn't take it).
In this column in June Bob Jones argued that chemists should hold up their hands and admit that they are really technologists as much as scientists. He is clearly correct, as far as he goes. However, I would like to take the argument a step further, and suggest that modern chemistry shouldn’t be regarded as a science at all, but rather as a handicraft, albeit one with an unusually strong quantum mechanical underpinning.
The establishment, some fifty years ago, of the theoretical foundation of molecular and solid state structure, of kinetics and statistical thermodynamics, was a new beginning for chemistry, turning our subject from a science into a truly creative discipline.
Consider what we do, whether in industry or in academia. We make new molecules or materials, either to perform some useful task (pharmaceuticals or high temperature superonductors, for instance), or for their beauty (fullerene is my favourite example), or, on a few happy occasions such as the development of dendrimers, both. What very few of us do is to make testable hypotheses about how the world works.
This turns out to have ramifications in another issue that has concerned me for some time. I’m sure most chemists agree that they are woefully under-rewarded compared to the professions. We don’t have a powerful association that can limit entry to our field and therefore keep salaries high. We could try to push the C.Chem MRSC approach, but I think I have a better idea.
I propose that we recognise that we are moleculesmiths, and should form ourselves into a Guild, maybe even with fancy dress (black labcoats and gold safety spex perhaps?) and secret handshakes. We could probably get government support for the idea that new compounds can only be introduced to the market by Master, or Mistress, Chemists. After all, the rack of approvals we need these days - fda, coshh, einecs, tsca - means that industry is now de facto reliant upon responsible, experienced chemical craftspersons.
Entry to the Guild could be fiercely restricted. Even to be accepted as an apprentice the aspirant would need a BSc, for we still need a scientific understanding to practise our trade successfully. But the PhD would be replaced by a Masterpiece Examination, probably still in thesis form, where the journeyman chemist (itself an idea to play with) would present his or her new molecules or materials and demonstrate their usefulness and elegance. However, once in the Guild we could command salaries undreamt of except by lawyers.
The downside, of course, is that as the government recognises our art for what it is, state funding for chemical R&D would rapidly dry up. The Guild would have to set up its own laboratories, or buy space at the universities. Most of the post docs would be forced out into industry. But to me this would be no bad thing. There would be a huge infusion of creativity into the commercial sector, while the former academics would benefit from the superior discipline of making something that can be sold profitably, rather than those of peer review and the citations index.
It probably won’t happen, but let’s at least be honest with ourselves, and change our self-image. We are moleculesmiths , and should be proud of it.
Published in (the last ever edition of) Chemical Innovation, December 2001
I had been intending for some time to write about diet, nerve gases and disease prevention, although I hadn’t particularly planned a piece with a seasonal angle. However, the sad demise of one of my favourite chemistry journals meant that my last chance to tackle this topic would come with a December issue. Fortunately, the Brussels sprout provides a suitable link.
In Chemtech in June 1999 I wrote about my accidental generation of trace quantities of ethyl isothiocyanate, a military poison, during an attempt to make fire retardant acrylic fibres. I later came to realise that I needn’t have panicked. Indeed, I may have been doing myself some good. It has been known for some time that brassicas, and in particular the Brussels sprout, contain compounds that appear to protect against a range of cancers. What I didn’t know was that the most important compound, a glucosinolate known as sinigrin, isn’t the protective agent at all. It’s a metabolite of this – allyl isothiocyanate. Apparently this seeming nasty causes precancerous cells to commit apoptosis.
Now I don’t know if the situation in the US is the same as it is in the UK and Ireland, but over here just about the only time anyone ever eats Brussels sprouts is with their Christmas roast. Indeed, I believe some health organisation came up with the slogan: “Sprouts are for life, not just for Christmas.”
I have therefore been wondering about the health implications of other parts of the traditional seasonal fare. I haven’t found any other nerve gases, but otherwise there’s a lot to chew on (sorry). Most people now know about the cardiac benefits of the occasional glass of red wine, while the value of cranberries in helping with urinary tract infections is almost part of folk medicine. Perhaps less well known is the importance of the nut bowl, and particularly the walnuts, in preventing coronary heart disease. Or that of cinnamon in the mulled wine and Christmas pudding in the treatment of diabetes.
So is everything good for us? Well, I have my doubts about the brandy butter, and the after-dinner cigar. The potatoes probably shouldn’t be roast, but for the rest who knows what dietary science will throw up? In our family we treat ourselves to a little smoked salmon before our Christmas lunch. Oily fish have recently been given gold stars for being good for the heart. Will salmon win any prizes in the future, or should we switch to smoked mackerel? What about the chestnut stuffing? The turkey flesh itself?
The suspicion has to be that for omnivores such as homo sapiens variety is what matters – this seems to be the line that dieticians are increasingly taking. But if evolution has driven us that way, why shouldn’t a varied diet also be beneficial to carnivores and herbivores? Perhaps sheep and rabbits would live longer if they ate a portion of sardines once a week. A favourite Far Side cartoon of mine has one lion saying to another: “Boy, I could just go a nice salad!” Maybe it’s not as ridiculous as it sounds.
Anyway, this year we’ve decided to experiment on our cats. We don’t expect too much trouble in persuading them to eat turkey and smoked salmon. They may even drink a drop of port instead of milk – I once knew a dog who loved it, although whenever he drank it he would have to spend the whole of the next day lying down with his paws over his eyes. But we will probably get some puzzled glances when we fill their bowls with sprouts and walnuts. Perhaps we should coat them in aspic.
I had better sign off here. I want to leave a little space to say how much I have enjoyed writing for Chemtech and Chemical Innovation over the last few years, and to thank Marcia Dresner and Mike Block for the encouragement they have given me in developing this column. Chemistry as a subject is facing difficult times, and we chemists are the only people who can do anything about it. So here’s a final seasonal thought: we should each of us resolve to do something in 2002 to slow the decline – to talk to a local school perhaps about the great careers that chemistry can give you, or to write to your newspaper when ever you see an article knocking “chemicals”. Whatever. It’s up to you. If we don’t do anything we’ll be extinct in a generation.
Merry Christmas.
Published Chemical Innovation October 2001 & one of my favourites.
It's June as I write this. 1 am wrapped up warm against another Irish summer, and thoughts of global warming rarely intrude, quarrels over the Kyoto Protocol notwithstanding. But I was forced to dwell on the topic recently when I read of an article in Geophysical Research Letters (1), reviewed in New Scientist (2). I thought at first that either the original piece or the review had been an April 1st hoax, but this couldn't be – I looked up the original on the Web, and New Scientist was a day too early. According to the authors, the worlds output of carbon dioxide from the combustion of fossil fuels could be soaked up by a shallow limewater lake the size of Minnesota. The idea was that the calcium carbonate produced would be recycled back to the oxide, and the CO2 would be permanently tied up in a basic magnesium silicate.
Getting such a scheme off the ground (or more accurately, sunk a few feet into the ground) could present a few problems—the Minnesotans might object for a start. So I wondered what could be done on an individual basis. Apparently, humanity is busy adding 7 Gt of CO2 to the atmosphere every year. Taking a Pareto approximation (i.e.. that 20% of the population is responsible for 80% of the mess, which is probably about right), then the average family of four in the developed world must produce 430 kg/week of the gas. This seemed like an awful lot until I realized that my own family's two cars belch out something like 200 kg/week between them.
Now I know that doubts have been raised in this publication (3) about the causal connection between CO2 levels and global warming, and I share those doubts; but the Precautionary Principle, and even good neighborliness, suggest that we shouldn't be venting off to the atmosphere nearly half a tonne of waste gas per family per week.
So what can the concerned family do, short of giving up one or both cars? I considered creating our own limewater lake, but it would need to be about 625 m2, which is considerably bigger than our back garden. We would also produce several tonnes per week of magnesium carbonate silicate, and I don't imagine, the binnies (trash collectors) would be too happy about taking it away.
Another idea: tree planting. Our middle daughter, Sally, has been raising an oak tree from seed. It's still sitting on our window ledge (tiny oaks from mighty acorns grow), and I reckon it's soaking up about 10 g of CO2 every 7 days. Therefore. Sally should be planting 430,000 of them. We got her started, but her teacher complained that her school work was suffering.
So what's left? Until zero-emission cars come along [see September CI, pp 34-38 - Ed], we're going to have to think laterally. If we want to reduce our environmental impact without spoiling our lifestyle, we'll need to spoil other people's lifestyles. If I can force four or five commuters out of their cars and onto public transport every day, then I'm doing the business. I considered slashing tires on all the local SUVs (a good hobby in itself), but then I remembered that all the scrap tires would end up in a dump, burning and causing more damage than the gasoline. So now I prefer a more subtle approach. Siphoning off all the fuel is a good one - we can use it in our own cars, which saves money as well, but it's not that easy with most modem automobiles. Draining the lube oil is also good, and quite a bit easier, it also has the advantage that nothing happens until the victim is several miles away, which diverts suspicion.
But other peoples car travel is really too small a target. Doing away completely with a few gas-guzzlers has a lot going for it, hut long-haul air transport is a much more worthy adversary. I'm now contemplating a career change: I could train as an air traffic controller, start at somewhere like Heathrow, and then promptly instigate a long, bitter strike. Six months of that and 1 wouldn't have to worry about my own CO2 emissions ever again. But I had better get that long-planned trip to Australia in first.
References
(1) Elliott, S.; Lackner, K.; Ziock, H., Dubey, M.; Hanson, H.; Ball, S.; Ciszkowski, N.; Blake, D. Geophys. Res. Lctt 2001, 28, 1235-1238,
(2) Samuel, E. New Scientist, March 31, 2001, p 14.
(3) Essenhigh, R. Chem. Innov. 2001, 31 (5), 44-16,
Published in CHEMTECH June 1999 as "The Janus Element"
Books I wish had never been written: No. 1 The Periodic Table (Il Tavolo Periodico) by Primo Levi. That’s about it, really. Not that it is a bad book - quite the reverse. I regard it as the best book ever written by a chemist. If you have never read it, you must. No, my problem is that I wish I had written something similar myself, first.
Levi was an Italian Jew whose career spanned the war. His book is autobiographical, and each chapter, named after an element, relates a period of his life and how that element impinged on it.
A super idea, something that every chemist should emulate. But the lay public is probably not ready for thousands of “Periodic Tables”, so we will have to write for each other, in columns such as this, or via an internet discussion group. (Does anyone know if such a group exists already?).
The element that has haunted me most throughout my career, flickering into my consciousness like the will-of-the wisps it causes, is phosphorus. I see it as a Janus element, along with nitrogen and chlorine, a bringer of life and death, essential but much abused. Regular readers of this column will know that the burning red allotrope impinged on me quite literally in the sixth form, and inorganic phosphates caused me no end of frustration while I was working for my D Phil, but I want to concentrate here on neurotoxins.
The chain of thoughts that led me back to Levi’s book, and to my own phosphorus “chapter”, began Proust-like with an apparently unrelated, trivial incident. I needed to send some flammable adhesives across the Atlantic, and therefore needed to encase them in United Nations approved packages. This eminently reasonable interference by an international body in chemical commerce brought to mind a more irritating example from my previous job working with polyurethane foams. Dimethyl methylphosphonate (dmmp) was a marvellous, innocuous additive for foam formulations, reducing viscosities and improving fire retardance without any loss of performance.
Unfortunately, it can also be a precursor for much nastier materials, so the UN declared it a controlled substance, and our supplier withdrew it. Sensible, perhaps? Well, not really. It’s no harder to make dmmp than it is to react it further. Anyone with the ability to synthesise the toxins could easily make the raw material. But whatever the merits of the case, the recollection established in my mind the link between beneficial phosphorus compounds and their lethal derivatives.
My mental rewind then took me back to a previous stage in my career, to when I was working with acrylic fibres. Phosphorus in various forms is often used to reduce the flammability of synthetic fibres. It was already known that polymers based on trimethylolpropane (tmp) caused problems in fires if there was phosphorus around. Bizarrely, the beautiful, innocent-looking by-product molecule
is intensely toxic, interfering with the function of acetylcholine. But that shouldn’t have been a problem - there were no traces of tmp in our acrylic fibres. We merely wanted to copolymerise a few percent of a vinylphosphonate with the main constituent, acrylonitrile. We were carrying out the reactions in concentrated aqueous sodium thiocyanate, a good solvent for polyacrylonitrile. Things were going well - the expected level of phosphorous was being incorporated in the fibre, the fibres were showing the expected improvements in limiting oxygen index. But the solutions had an unpleasant mustardy smell. Head space analysis showed that for the diethyl vinylphosphonate we were making traces of either ethyl thiocyanate (Toxic) or ethyl isothiocyanate - an early nerve gas. The phosphonate ester was acting as an alkylating agent. When we used bis-beta chloroethyl vinylphosphonate
CH2=CH-PO(OCH2CH2Cl)2
the solutions smelled even worse, but we couldn’t detect anything. Heaven knows what we were making - we didn’t wait to find out, but closed the project immediately.
Typical of phosphorus. It has been an untrustworthy friend to humanity since the beginnings of the industrial revolution, since match workers started to develop “Phossy jaw”. But also typical of the fascination of chemistry. We think we understand our subject, but there are surprises around every corner. Delightful surprises most of the time, but we never know when we’re going to wake a Balrog. So the incident is also a reminder of the dangers of hubris. Industrial chemists and their managers aren’t bad people, but an arrogant faith in our control over the elements has brought much misery, sick operatives and sterile rivers. The chemical industry has a poor reputation, a public perception of a corporate cavalier attitude to employee safety and the environment, a perception shamefully accurate until relatively recently. We need to remember that our subject is two-faced. Will-of-the wisps are bewitching phenomena. They have led people to their deaths.
Published Chemical Innovation July 2001
Last time here I discussed chemical anniversaries, but ducked the question of when the chemical industry started. Since then, prompted fortuitously by a book I was ask
ed to review (which I posted last year) for another journal(1) , I now have a couple of candidate developments.
Clearly, there’s a matter of definition to sort out first – what counts as chemical industry? I went along
with public perception, and discounted those industries that use chemicals to produce consumer items. The public is glad to accept paper, leather, soap, glass and pharmaceuticals. Ergo they’re not really “chemical”. This left me with the production of chemical intermediates for these and other industries – largely the production of bulk organics and inorganics.
Sticking with lay opinion, I also had to contend with the image of the chemical industry as “The Great Polluter”. These days the epithet is manifestly unfair. The industry has cleaned up its act enormously and now has much less negative environmental impact than say agriculture or transport. However, we must admit that at times the record of our great endeavour in this respect has been scandalous.
And yet, governments and street mobs have always been surprisingly tolerant of industrial processes that cause localised environmental degradation, so long as the products of such processes provided employment and were of sufficient utility. Until very recently, slaughterhouses, soap and glue works, leather tanneries and paper mills were hardly models of Responsible Care. I therefore took the view that my ur-industry needed to produce something of enormous social benefit.
Already the choice was narrow, but should I include metallurgy? If I did then there was no need to look beyond the introduction of the blast furnace into Europe in about 1500. Neither the Bronze Age nor the prehistoric Iron Age counted. The first brought the pollution (arsenic) but produced a metal still sufficiently expensive that it didn’t really impinge on the lives of the masses. The second caused less environmental damage, but any social benefits it brought in terms of agricultural implements were more than outweighed by the arms race it engendered: arrow heads, swords, chain mail, plate armour and eventually fire arms and artillery. But the blast furnace changed the equation. It was now possible to produce iron in much larger quantities, and it found its way into a plethora of new applications, but at a cost. The demand for charcoal was so great that most of France and England was deforested.
However, if you don’t include metal extraction as part of the chemical industry then there’s only one real contender under my criteria: the Leblanc Process. Depending on how you look at it, it was either all the fault of, or all thanks to the Americans and the French. During the American War of Independence and the Napoleonic Wars, England was cut off from North American and Baltic timber. But the demand was no longer just for charcoal for blast furnaces. Wood ash (or “potash”) was virtually the sole source of alkali for making soap, bleach, glass, paper and most significantly, given the military situation, saltpetre for gunpowder. Ironically it was a Frenchman in 1792 who cracked the problem of how to make sodium carbonate from salt, sulphuric acid, coal and limestone, and thereby kept the English industrial revolution going.
The pollution resultant from the Leblanc process was horrendous. Just look at the equations:
2NaCl + H2SO4 ® Na2SO4 + 2HCl
Na2SO4 + 4C + CaCO3 ® Na2CO3 + CaS + 4CO
It wasn’t just the HCl and the carbon monoxide venting off to the atmosphere, but the calcium sulphide piling up in foul smelling tips. And the sulphuric acid plants that had to be built next door didn’t help. Stretches of Merseyside and Tyneside became perhaps the most unpleasant places on earth for more than half a century until ways of using the by-products became commercially viable, and the rival (and much less polluting) Solvay and Castner-Kellner processes appeared.
And yet, the social benefits the process brought were equally dramatic. Soap and bleach, glass and paper became affordable household items. Deforestation was halted in the United Kingdom. To the authorities of the time, the health of the working classes in Widnes and Jarrow was a small price to pay.
I think the example is instructive. We industrial chemists tend to feel that we are unfairly treated, that we get insufficient credit for the benefits that our enterprise brings (true) and that each piece of environmental legislation that circumscribes our activities is unnecessary (false). We should recognise our power to change the world for the better, and accept our responsibilities in mitigating the negative effects of those changes without waiting for legislation. We won’t get any thanks for it, but who said Life had to be fair?
1. Russell, Colin A (ed) Chemistry, Society and Environment (A New History of the British Chemical Industry), RSC, Cambridge UK, 2000 – read it!
Published Chemical Innovation April 2001.
I know the mathematically challenged (a.k.a. “the general public”) think of us as pedants, but I am firmly with Arthur C. Clarke and, I imagine, the majority of chemists on this one: the twenty first century and the third millennium started this year (i.e. 2001), not last year.
Does it matter? Well, no - except possibly to a few fundamentalists, it’s not important what the average party-goer thinks. But when we chemists reflect back on key dates in the history of our subject it becomes clear that the year 1901, far more than 1900, stands out as “The Year That Chemistry Came of Age”.
It would be neater if we could also claim 1801 as the year that chemistry started, but unfortunately the subject is rather coy about its precise age. We can’t really say when the chemical industry began - the Bronze Age, maybe, or the first appearance of glass or ceramics spring to mind. However, the foundation of chemistry as a science was tantalisingly close to the start of the nineteenth century. Unfortunately the exact date is a little fuzzy. John Dalton proposed his Law of Partial Pressures in 1801, but his atomic theory had to wait a few years. By 1801 Lavoisier had already met Madame Guillotine, and Joseph Priestley was on his way out, while Gay Lussac and Avogadro were only beginning their careers.
We can view 1901 as a turning point with much greater confidence. True, Max Planck was a month early when he announced his quantum theory, and anyway the physicists claim him as their own. However, I think it is fair to say that the elucidation of atomic structure was of much greater importance to chemistry than to physics – let’s picture Planck’s contribution as a Christmas present to the chemists which they didn’t open until the following year.
1901 was also the first year of the Nobel prizes. Van’t Hoff won the chemistry prize, while the winning physicist was Röntgen for his work with X-rays, another piece of physics that the chemists have appropriated. The same year saw the birth of two key figures for our subject – Heisenberg and Linus Pauling.
But I also think of 1901 as a seminal year for the chemical industry. Many historians would agree that the industry mutated during the period from 1890 to 1910, but wouldn’t want to be pinned down to a single year. If pushed, they probably wouldn’t choose 1901. In pharmaceuticals, Bayer had launched Aspirin in 1899, while Erlich didn’t discover Salvarsan until 1910. For heavy chemicals, 1910 would again seem more important, for that was when Fritz Haber patented his high pressure trick for making ammonia, as would 1892 (the Castner-Kellner chlor-alkali process). Polymer chemists can point to Otto Röhm’s discovery of acrylic polymers in 1901, but the Viscose process wasn’t acquired by Courtaulds until 1904 while Goodyear only developed the accelerated vulcanisation process in 1907.
No, the reason I am so dogmatic stems from a discovery made in January 1901 that didn’t initially appear to have anything to do with chemistry at all. For that was when Pattilio Higgins struck oil at Spindletop in Texas and changed the world. Until then the only “gushers” had been in the Caspian region, a long way from centres of industry or from ocean transport. Suddenly what had been an expensive lubricant became a cheap fuel and feedstock. Clearly the automotive industry benefitted most from Spindletop – it couldn’t have started in earnest before 1901. But of almost equal importance was its effect on synthetic polymers, and all the industries that depend upon them – fibres, plastics, paints and adhesives.
So how about the state of chemistry in 2001? I don’t imagine it will be an annus mirabilis. Indeed, the subject as a science faces problems, with student numbers declining, lured away by biology and informatics. It’s not just the money - chemistry is now middle-aged, still healthy but maybe slowing down. This needn’t necessarily be a bad thing - perhaps those of us who are left will have more time for fun, more opportunities to be creative.
I could stop there, but I must tell you about another discovery made in 1901, one that links physical chemistry, biology and the event that all these centuries and millennia commemorate – the virgin birth. Jacques Loeb was studying the effect of varying osmotic pressure on the development of sea-urchins. I’ve no idea why he was doing this, but obviously osmotic pressure was all the rage at the time – witness the prize given to Van’t Hoff. Loeb found that if he added certain inorganic salts to sea water, unfertilised eggs could grow into larvae, the first recorded instance of chemically induced parthenogenesis.
So, hoping that my gloomier prognoses for chemistry prove wrong and that we see a renaissance in the next decade, here’s wishhing you all a happy twenty-first century.
Published Chemical Innovation October 2000
Regular readers of this column will know that I am fascinated by the origins of life from the viewpoint of a polymer chemist. What I hadn't realized until recently were the strange connections that molecular evolution has with the manufacture of carbon fibers, with underwear falling apart in the washing machine, and with anaerobic adhesives. And, embarrassingly, I find that the ancient Mesopotamians seem to have worked out the importance of oxygen millennia ago.
Their goddess Ishtar is linked to Venus, Aphrodite, Freya, and Kali, but more explicitly than her Indo-European counterparts, she is the goddess of both procreation and death. The ancient Babylonians are well known for their expertise in astronomy and mathematics, but I suggest that they understood a lot more about chemistry than is commonly recognized. My reasoning—specious, I admit—is that Ishtar had as her symbol an eight-pointed star. I believe that the Mesopotamians knew the atomic number of oxygen (though not the difference between s and p orbitals), and realized the importance of oxygen chemistry to the molecular origin of life and death. What they missed out on, and what the Teutonic nomads clearly understood, was the crucial role of transition metals. In the Norse pantheon, Freya had a twin, Frey who was connected with the mineral wealth of the Earth. Indeed, the element vanadium reflects this, for it is named after the twins' collective designation "Vanadis".
I have long been fascinated by that moment in evolution when microbes learned to handle oxygen. Until then, their spread had been limited, for the oxygen they produced as a byproduct of their growth was toxic to themselves and others. Furthermore, they had to process polymers anaerobically, limiting the polymers' usefulness for storing energy. And then a bright bacterium hit on the idea of fixing oxygen with iron- or copper-containing polymers. It was a pity that they didn't have patents back then, for he or she, the ancestor of us all, would have been a very rich bug.
Our love-hate relationship with element number eight continues to this day. Oncologists have shown that the radicals it produces in the body are a major cause of cancer, and that the antioxidants in fruit and vegetables are essential to our health.
Transition metal-oxygen chemistry got me into trouble as a child. I was working away in the kitchen with potassium permanganate from my chemistry set and whatever I could find—hydrogen peroxide, I think—when my test tube started to froth over, spilling corrosive purple gunk over the work surface. I was still trying to clean up the mess when Mum came in. I narrowly escaped a thrashing, but my test tubes and I were banished to the cold and damp of the shed.
I had more fun with manganese later, when I began my career. I was trying to catalyze the oxidation of acrylic fibers, the first stage in making carbon fibers. Virtually any transition metal helped, but manganese gave the reaction such a kick that the fibers burst into flames. Other chemists I know have had similar problems with manganese and what it can do to synthetic fibers. I understand that a major detergent manufacturer recently had to withdraw a new product, launched at great expense, when it was discovered that a manganese-based additive caused garments of a certain hue to dissolve in the wash.
On the positive side, I wouldn't be where I am today were it not for the influence that oxygen and those brightly colored salts from the middle of the periodic table can have on polymerizations. My current employers owe their existence to the chance discovery, in the 1950s, of an adhesive that wouldn't set up if there was oxygen about, and which would only set up in the presence of iron and copper in the lower oxidation states. Not much of an adhesive, you might think, but if you paint it onto a bolt, then screw the bolt into a nut, eliminating air, the stuff cures rapidly, securing the assembly. Much of modern engineering depends on this unheralded piece of serendipity, which made Loctite a great deal of money.
To return to Ishtar: 1 think we chemists should make her our goddess of oxidation, for without it, life forms would be much simpler and the termination of complex ones less common. She needs a new symbol, though—one that reflects her role as an Earth mother, the twin circles of Life and Death, and the diradical nature of the oxygen molecule.
Published Chemical Innovation July 2000
My wife wants credit for this piece, but she can’t have it. She wanted me to write about the genetics of tooth decay, for she hasn’t had a dental cavity in her life, nor did her grandfather, and nor have any of our three children. But I would rather force fit the debate about fluoridation of drinking water into one of my “Periodic Table” chapters, and give myself the excuse for more reminiscences. So, I’m going to demonstrate the clear links between the weaknesses of hydroxyapatite, ceramic fabrication, high tenacity fibres, insulating foam, the “missing mass” and the large scale structure of the Universe.
My own molars are full of amalgam. As a kid in Liverpool I wasn’t a big sweet eater, and I brushed my teeth religiously, but they were all drilled and filled anyway. I have long suspected that most of this treatment was unnecessary – I haven’t had a new cavity since I left home. My Dublin dentist tells me that it’s more to do with fluoridation, which started round about then, and that’s why my daughters have no problems. I’m not wholly convinced, but even if the Liverpool dentist wasn’t imagining dental caries, then there are other possible answers.
Liverpool water is famously soft and acidic, and I also wonder about affluence. I didn’t get much pocket money as a child, so the only confectionery I could afford were cheap boiled sweets, ideal for bathing your teeth for hours on end in a warm sugar solution. My own spoilt brats won’t touch the things, but live on chocolate, which has a much shorter residence time in the mouth. However, if your man here is right, then that is when the ninth element first impinged on my life.
Go with the flow. That’s where the name comes from. Fluorspar (calcium fluoride) was so called, long before fluorine gas was known, because of its use as a metallurgical flux (same Latin root). In my ceramic days I tried using it to help sinter my phosphates, but it didn’t work. I also thought I wanted to make tantalum oxyfluoride, but as that would have involved dissolving the oxide in HF and evaporating to dryness, I decided I didn’t want the stuff after all.
Moving into industrial R&D, in the fibres area, I was immediately involved with fluorine chemistry again. DuPont had just put out the Kevlar patents, showing how they could make extemely strong fibres by spinning them from liquid crystalline solutions. My employers wanted to know if we could pull off the same trick with the polymers we routinely used, notably cellulose acetate. Briefly, the answer was yes, but only if we used trifluoroacetic acid as the solvent. Once again, ultra-strong cellulose acetate fibres suddenly didn’t look quite so attractive.
The F element continued to dog my career when I moved to working with polyurethane foams. They had been blown for years with chlorofluorocarbons, apparently magic molecules – non-flammable, non-toxic and, so we thought, great for the environment. Within months some pest discovered the Antarctic ozone hole, and all our development programmes had to be put on hold while we scrambled around for alternatives. It might seem unfair for me to be blaming the fluorine, when it’s the chlorine that is believed to cause all the damage. But it is the fluorine that gives the molecules their long life. Without it the little devils would never reach the stratosphere.
Until then I hadn’t been aware of the microscopic structure of urethane foams. The cells are roughly dodecahedral, but with virtually all the polymer in the struts that run around the windows. The windows themselves are extremely thin. Now, astronomers believe that this is precisely the structure of the Universe – all the galaxies sit inside filaments that join up to form a foam. The cells themselves are apparently empty. What made space froth up like that? The physicists go on about an inflationary phase, about Higgs bosons and the like, but it all seems rather conjectural. And what about the “dark matter” that supposedly makes up ninety percent of the mass of the Universe, but which the astrophysicists can’t find? They ought to talk to the chemists. The answer is clear – CFC’s! To date, nobody has checked out this important hypothesis, so I’m sticking with it.
It’s a bit of a problem if I’m correct though. The Montreal Protocol isn’t going to help very much if inter-stellar space is awash with ozone-depleting molecules. Some further thoughts: What happens to the fluorine when CFC’s break down in the polar spring? Does it enter the food chain? And is that why the Inuit don’t suffer from tooth decay?
Published Chemical Innovation April 2000
Marcel Proust could access a shortcut to deep memories by nibbling on a madeleine. I don’t know whether it is sad or something to be proud of (I think the latter) but I managed to activate my own mental time machine by reading an article in Chemtech as was. An article on soot.
My personal tour of the periodic table in this column has taken me in recent months from phosphorus through tantalum to gold and scandium, but now I must discuss carbon. Not all the fiddly organic chemistry, but the element itself. And I don’t mean pretty, pretty diamonds, or fancy fullerenes, but honest, black graphite.
Like many adolescent boys I conducted my first extra-mural chemistry experiments with powdered charcoal, sulphur (I’m English, so I insist on the “ph”) and saltpetre. These first essays into pyrotechnic technology were undramatic, and I soon progressed to chlorate and sugar or ammonia and iodine, but I have retained a fondness for element number six, and the mess it can make, to this day.
Carbon black is of surprising economic importance. Compounded with natural rubber it forms a sort of interpenetrating polymer network which shows superb mechanical properties that are very expensive to obtain with purely synthetic elastomers. That’s why all tyres, even on top of the range cars, are black. The same trick works with polyurethane adhesives, giving excellent products for sticking in car windscreens, which is why I have been handling the stuff in recent years. The problem is, the adhesives are themselves moisture-curing, so that the carbon black has to be rigorously dried. The only quick way I found to do this on a sufficiently large scale was to use a small fluidised bed dryer, resulting in my laboratory turning black, being labelled “The Carbon Lab” and being shunned by the drippy conventional adhesive formulators elsewhere in the building. Unfortunately, carbon black has been shown to cause testicular cancer amongst chimney sweeps, so it’s going to become increasingly difficult and expensive to process the material.
Taking two career steps back I recall having great fun trying to accelerate the oxidation of acrylic fibres (the first stage in making carbon fibres) and producing clouds of soot and carbon dioxide instead. And going back to school I was delighted by a bench experiment, one that wouldn’t be allowed any more, where we generated chlorine and acetylene in the same test-tube and produced a series of beautiful black smoke rings.
But the Chemtech piece on the structure and characterisation of soot particles (July 1998) took me back to that fertile time for reminiscences, my university days. An old college friend of mine is Tony Marchington, now CEO of Oxford Molecular. For the diligent researchers amongst you he has already appeared, anonymously, in this column. As a student he shared a house with Walter Hooper, a former secretary to C. S. Lewis, and the world’s leading authority on the Narnia man. In those days there was a furious controversy amongst Lewis scholars. After Lewis’s death his family is supposed to have destroyed many of his papers in a bonfire in his back garden. However, another prominent academic with an interest in Lewis refused to accept this and led a vitriolic campaign accusing Hooper of secreting the said papers for his own benefit.
Walter was naturally upset, so Tony wrote an article for a journal devoted to Lewis studies, purportedly coming from the Oxford University Department of Physical Chemistry (where he in fact worked). In the paper he claimed to have subjected several tons of topsoil from Lewis’s garden to a technique he called “Carbon Particle Analysis”. He concluded that there could not have been a bonfire on that site for at least eight hundred years. Astonishingly, the paper was accepted, and the anti-Hooper faction tried to use it as ammunition until the hoax was uncovered.
Imagine my delight therefore when the researchers at MIT and Caltech showed that just such a technique could work. I hope it wasn’t a hoax. I thought then about writing to Chemtech, but in spite of some serious web-surfing I couldn’t uncover any of the original correspondance, and the matter slipped from my memory again. It remained in deep store until a few weeks ago, when in the space of a few days I received a business letter from Tony, and during a flying visit to Oxford I bumped by chance into Walter.
Lewis’s old Inkling friend, Tolkien, believed that such meetings never happen by “chance”, that they are all connected somehow with the great struggle between Good and Evil. I can’t quite see how a few hundred words on graphite can frustrate the designs of the Dark Lord. Perhaps it’s something to do with testicular cancer. Anyway, every little helps. Read the Chemtech piece again. When you are called up for The Last Battle, and the clouds of smoke are billowing around the four horsemen, at least you will know more about the structure of those smoke particles.
