Resonance Issue 8 | Spring 2018
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Co The University of Sheffield’s Chemistry News Team
NANOBOTS SMARTPHONES PLASTIC MONEY A diagnostic revolution? Are they sustainable? The science behind it.
Resonance
The University of Sheffield’s Chemistry News Team Editor Josh Nicks
Resonance Resonance is a biannual newsletter produced by chemistry students at the University of Sheffield. It aims to provide insights into unheard stories from the department and to engage you with issues in the wider scientific world.
Design Editors Josh Nicks and James Shipp Social Media Coordinator Josh Nicks
Contributing Authors Josh Nicks James Shipp Hannah Winter Imogen Holmes Zoe Smallwood Beth Crowston Joseph Clarke Nara Vasa Sam Harrison Jennifer Train Copy Editors Josh Nicks James Shipp Dr Grant Hill Prof Anthony J. H. M. Meijer
Email chem-news@sheffield.ac.uk Printers Print and Design Solutions Bolsover Street Sheffield S3 7NA
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Editorial
T
his is now the eighth issue of Resonance, with a new pair of editors and a new batch of authors, but its purpose of communicating interesting, important science and the news of our department remains. Resonance aims to showcase the department and all the great and inspiring things that occur here to its readers; be they undergraduates, postgraduates, academics or prospective students and their parents. However, at heart Resonance is a chemistry magazine, and the articles within also focus on conveying fresh and gripping topics that readers of all backgrounds can use to learn and enjoy. Having assumed the post of Editor from Beth Crowston in October, I would like to thank both her and of course Joe Clarke for their continued input and dedication to Resonance, and for doing such a fantastic job that I’m not quite sure how to follow it! I must also give thanks to James Shipp, my co-editor, for his inspired ideas and for all the effort he has put into this issue. Though obviously, the articles are what make Resonance, so I’d like to commend those who have devoted their time to writing for this issue. This issue boasts a breadth of topics; ranging from nanobots and their diagnostic potential by a local college student, Imogen Holmes, to an in-depth interview with our new head of department by our exdesign editor and recent employee of science communication firm Notch Communications, Joe Clarke. 2017 is brought to a close by Zoe Smallwood, with a reflection on the many distinguished achievements of our department last year, while Hannah Winter delves into the chemistry of our minds and why certain scents can trigger such happy memories. Happy reading.
Joshua Nicks
Contents
On the Cover
4 Nanobots
Can nanoscale machines help shape the future of the medical industry?
In This Issue Editorial
1
The Chemistry of Nostalgia
3
Nanobots
4
Nitrifying our Earth
5-6
An Interview with Peter Styring
7-8
Smartphones: Behind the Screen
9-10
Elemental Factfile: Gold
9 Smartphones: Behind the Screen
Is the industry sustainable at all? What you didn’t know about the device you can’t live without.
10
The Department of Chemistry in 2017
11-12
Student Projects
13-14
PepsiCo: A Factfile
14
Plastic Money
15
Nobel Prize 2017
16
Chemistry Crossword
17
Get in Touch @resonancenews @SheffieldChem
15
@sheffield.chem The University of Sheffield University of Sheffield Chemistry Alumni @Resonance_Sheff
Plastic Money
What actually makes our new currency, and how chemistry was fundamental in designing it.
chem-news@sheffield.ac.uk www http://bit.ly/2weV7M1
The University of Sheffield || Resonance Issue 8
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Insight
The Chemistry of Nostalgia By Hannah Winter
S
o many aspects of our seasonal traditions are filled with nostalgia: the lights on the tree, the taste of mince pies or the heat of the fireplace. With the short days and cold nights, our senses lead us to reminisce. Out of our five senses, however, it is smell that really transports us back in time. Imagine the crisp smell of the air after snow, the smoky bonfire on the 5th November or your first pumpkin spiced latte of the year. It’s often astounding how vivid the memory within the scent of a slowly jading Christmas tree can be. But how is it that smell brings back such strong emotions that none of our other senses can compete with? First, a little background about how
the olfactory (relating to smell) system works. The olfactory sensors in the human nose are covered in a layer of mucus, so when we breathe in, air is passed over this mucus and volatile chemicals from our surroundings become dissolved in it. It is the following interaction of these dissolved chemicals with our receptor cells that cause ‘smells’. Hence, for a chemical to be smelled it is essential for it to not only be volatile, but also soluble in this mucus. The olfactory sensor cells have over 1000 different types of receptors, resulting in a much more complex sense compared to our other four, leading to the ability to differentiate between many types of stimuli. These cells also regenerate and change according to what a
person frequently smells (this is why you cannot smell your own scent). This complexity is one theory as to why odour stimulated memories are so sentimental. The other main theory is more closely related to neuroscience, but investigating the complex systems that are our own brains is still largely a work in process. However, it is known that the stimuli from the nose are processed in the olfactory bulb which is directly connected to our hypothalamus and amygdala; the two areas most associated with memory and emotion. So, the next time that certain smell brings back memories of home, remember that, really, it all comes down to chemistry.
Cinnamaldehyde (C9H8O) is the source of the aroma (and
flavour) of most of your favourite autumn bakes and lattes. It is the major component of the essential oil found in the bark of cinnamon trees (cinnamon sticks).
Menthone (C10H18O) is a monoterpene and ketone which is found in
peppermint, and is often used in cosmetics due to its fresh minty aroma. It is one of 4 possible stereoisomers and is closely related to menthol.
Pinene Bornyl Acetate The
two
for the odour of pine trees.
(C10H16)
isomers
and
(C12H20O2) are responsible
Bornyl acetate has the typical fresh pine odour while the two isomers of pinene give the pines a smell particular to their region with the (-) isomer being more common in European pines and the (+) isomer in North America. Beta-pinene has a woodier, forest like smell in comparison to the alpha isomer.
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Interview Feature
Nanobots By Imogen Holmes
P
icture a robot, and the image that might come to mind is one of a metallic machine, often a crude representation of a human, designed to perform simple tasks such as cleaning or cooking. An image less likely to come to mind is that of a nanoparticle-sized machine, moving within your bloodstream. Welcome to the world of ‘nanobots’, or nanotechnology as most scientists prefer to call it. The idea of nanobots first entered the scene in 1959, when Richard Feynman gave a lecture titled “There’s plenty of room at the bottom’” introducing the idea that nanotechnology could one day be used within the body as part of biological and medicinal systems. However, nanotechnology faced a major limitation; electron microscopes of that era were not powerful enough to resolve individual atoms. Two major breakthroughs allowed progression in nanotechnology: the scanning tunnelling microscope was developed in 1981 by Heinrich Rohrer and Gerd Binnig, and Binnig then went on to develop the atomic force microscope in 1986. These techniques allowed materials to be manipulated at the nanoscale, and have unlocked the great potential of nanochemistry, with some of the most exciting current research being nanobots.
Figure 1. Thirtyfive individual xenon atoms arranged to spell IBM (the company where the technique was developed) on a nickel crystal using a scanning tunneling microscope.1
Figure 2. An artificial muscle, dubbed a ‘yarn motor’, that may be used to propel nanobots. Made out of carbon nanotube ‘yarns’, they twist and untwist to act as a synthetic flagellum, propelling the attached device.2
Devices are being developed with features that a medical nanobot would require. A nanobot with a metal helix type structure has been developed which can attach to a sperm cell, aiding its transport to an egg cell by use of a magnetic field - although they have been unable to use the nanobot to actually fertilise the egg. However, with further research this may be of huge benefit to couples struggling to conceive, as a low sperm count is the main problem in 20% of infertility cases. Alternatively, the power of a sperm cells flagellum (or that of any other mobile cell) could be harnessed by a biohybrid nanobot, which could bind and deliver drugs to specific cells, removing the need for motors. This would be particularly useful when treating cancer, as an alternative to treatments such as chemotherapy, which harm all fast dividing cells - not just cancer cells.
In 2009, nanobots with tails that mimic flagella were developed, and in 2017, a faster nanobot was developed that mimics front crawl movements. It is able to ‘swim’ through viscous liquids (such as semen), and is being tested on other bodily fluids such as blood plasma. Perhaps in the future these nanobots may also be used to deliver drugs to cells in our bodies. Most trials have taken place in vitro, as many use toxic fuels such as hydrogen peroxide, which are toxic to humans. Hence, nanobots controlled by a magnetic field may prove to be better alternatives. Another problem to solve before use in the human body, is removal of nanobots when treatment has finished. Possibilities include using biodegradable materials, or guiding the nanobots out of the body through the digestive system. There are some remaing issues: manufacturing would not be cheap, as materials must be highly pure with few defects. Would the benefits of this treatment justify such a high price? Could nanobots become autonomous, or find some way of replicating inside the body? However, fastforward a few decades and having nanobots injections may be a normal part of any hospital trip, revolutionising fertility and cancer treatments, and even other areas of medical science, who knows? 1. http://bit.ly/25bc8jj 2. http://bit.ly/2DJJAaP
The University of Sheffield || Resonance Issue 8
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Insight
Nitrifying Our Earth By James Shipp
N
itrogen is vital for healthy growth of plants and crops. Artificial fertilisers are added to our crops to supply nitrogen, but could we be driving nitrification of soils too far?
One of the key cycles in the natural world is responsible for conversion of nitrogen into various products through the atmosphere, soil and oceans. The key steps in the nitrogen cycle are: Fixation and Ammonification This is performed via capture of N2 by symbiotic bacteria in the root nodules of plants (known as diazetrophs). These organisms possess a nitrogenase enzyme which uses hydrogen and nitrogen to produce ammonia (NH3), the starting material for the production of key amino acids and other organic compounds. When a plant dies, bacteria in the soil convert organic matter back into ammonium (NH4+ ), releasing fixed nitrogen into the environment where it can be used by other organisms. Nitrification The conversion of ammonium to nitrite (NO2−) is performed by ammonium oxidising bacteria (AOB), two key examples being Nitrosomonas and Nitrosococcus. Other species, such as Nitrobacter and Nitrospira, perform the oxidation required to convert nitrite to nitrate (NO3−). Denitrification The reduction of nitrates by anaerobic bacterial species such as Pseudomonas and Clostridium back into N2 gas is the step that completes the cycle. These species use such nitrate anions in place of oxygen during respiration, the inert, gaseous N2 produced then diffuses back into the atmosphere, where the cycle repeats.
Figure 1. The nitrogen cycle.
Figure 2. From left to right: Nitrosomonas, Nitrobacter and Pseudomonas bacteria.
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Insight Artificial Nitrogen Fixation - the Haber-Bosch Process Nitrogen fixation is not just limited to natural processes, in fact, artificial fixation is critical for modern life. The Haber-Bosch process, which replaced using mined nitre as a nitrogen source, produces 450 million tonnes of nitrogen based fertilisers per year. The majority of these are anhydrous ammonia, ammonium nitrate, and urea. They are produced in a reaction between nitrogen and hydrogen at high temperature in the presence of a catalyst, typically iron doped with K2O, CaO, SiO2, and Al2O3. The original catalysts suggested by Fritz Haber were osmium, or uranium. However the use of these was not widely implemented because of how rare and toxic these metals are. Artificial nitrogen fixation has had a dramatic impact on our ability to grow food, and can be thought of as one of the main reasons for the population explosion we are experiencing to this day.
Figure 3. The Haber-Bosch Process
It has been estimated that without these fertilisers we would require almost four times more agricultural land than we do today to produce the food we need. Impact of Artificial Fertilisers However, the use of artificial fertilisers on crop land has led to significant environmental problems, which, if allowed to continue, could have severe consequences for our soil, rivers, and oceans. The rate-limiting step of the nitrogen cycle is nitrification; therefore there is a natural limit to the amount of nitrites and nitrates in the soil at any time. Adding a large excess of these ions to soils can lead to leaching of these ions into rivers. Due to both their high solubility in water, and the inability of soils to retain these excess anions, nitrites and nitrates are prone to being washed out of soils into the groundwater. In time, the ions washed out of agricultural soil will end up in oceans. The enrichment of the sea with nitrogen based anions leads to rapid growth of algae within the water, a process known as eutrophication. This occurs because nitrogen levels are normally the limiting factor in marine ecosystems, so when an excess is available the habitat can support a much larger population of algae, leading to agal blooms.
Figure 4. Three examples of algal blooms in different environments.
An algal bloom will absorb most of the sunlight at the surface of the water. It causes large changes in the amount of oxygen available in the water. These changes lead to the suffocation of fish and other marine animals. Moreover, some algae release neurotoxins, such as domoic acid, which are very harmful to livestock or humans. This can be problematic for the food industry if shellfish and other edible species absorb the toxins. Figure 4. Domoic acid - the neurotoxin
The nitrogen cycle is a carefully balanced sequence of natural process- responsible for amnesic shellfish poisoning es which regulates nitrate concentrations in our soils. The use of artificial fertilisers could tip the balance, leading to huge excesses of these 1. http://bit.ly/2lsmdHP ions in the oceans. If not properly controlled, or if new sustainable 2. http://bit.ly/2zLkW3z 3. http://bit.ly/2zNs13M methods of farming are not developed, this could lead to significant problems in the near future, as our oceans become dominated by toxic algal blooms.
The University of Sheffield || Resonance Issue 8
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Interview
An Interview with Peter Styring I
n August 2017, Prof. Peter Styring moved from Chemical Engineering to become head of the Chemistry Department. With an academic background beginning in this very department, he has forged a career as a leading academic expert in CO2 utilisation, writing several policy documents that have shaped the landscape of research on carbon dioxide utility. Joseph Clarke had the opportunity to talk to Peter about his experiences in academia, research interests and activities outside the department. First, can you just give a brief outline of your academic career? So, I started in Sheffield in 1982 as an undergraduate before graduating in 1985. I then began a PhD with Peter Maitlis (who is 85 next year) and Duncan Bruce, who is now HoD in York, and David Dunmur, who was an ex-HoD here. It was a great experience and I decided not to leave academia. So, I got my first Postdoc in New York, State University of New York and Stony Brook which was set up by Fraser Stoddart, who was a great influence. Actually, Fraser was my organic tutor during my undergraduate and Mark Winter was my personal tutor! I then returned to the UK to take up a lectureship in organic chemistry at the University of Hull for 11 years. I was persuaded to join the chemical engineering department here in 2000 as a senior lecturer and then became Professor of Chemical Engineering and Chemistry in 2007. In reality, I was doing a lot of chemistry under the guise of chemical engineering. Then I heard about the HoD job here and, subsequently, here I am. Can you give a brief summary of your research area? I was in the inorganic department for my PhD research, but it was mainly cross-coupling reactions such as Heck reactions. Later on this moved into general cross-coupling reactions such as Suzuki, Heck and Kumada. Then at an EPSRC event in 2007, representatives of other universities and myself, had to devise new sustainable chemistry routes to new products. This really was the start of my interest in CO2 chemistry. As such, my interests then evolved into using carbon dioxide as a C1 feedstock to replace petrochemicals. In 2010 we formed the CO2Chem network, a global network of academics, industry and policy makers, known as the Triple Helix model. The three groups are all intertwined and connected. We’re currently at about 1200 members, with me as chair. We’ve just received two years extra funding leading to a total of nine years of funding, which is fantastic.
Peter Styring starting the Alternative Aviation Fuels session at COP22.
In abroad sense, what does your research group look into? In a nutshell, we focus on CO2 utilisation and sustainability via resource recovery. We also look into carbon capture, which currently, is very inefficient. We are looking into new capture agents based on ionic liquids and amines, as well as organic and inorganic polymers. But my group is split between here [chemistry] and Chemical engineering at the moment. I’m hoping to move more people over here shortly, but there are certain experiments already established over in Engineering. I have moved six postdocs here, who are working loosely on policy and life cycle assessment, techno-economics, etc. They’re looking more into the process viability than directly at the chemistry itself. It’s almost like being a theoretical chemist, but with a focus on policy.
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Interview Still related to your research area, you have an interest in policy and you have written a white paper on Carbon Capture Utilisation, could you be able to tell us a little about that? Yeah, so this was in 2011, we got a grant to work with ECN (Energy Centre for Netherlands), and write a policy document called “Carbon Capture and Utilisation in the Green Economy” (see: bit.ly/2nlKsIO). You could almost consider it a review paper but with sections aimed at policy makers. It gained quite considerable global press interest, taken up by Reuters and the Guardian. We’re also able to gather information on citations and, last time I checked, there were 23,000 hits on the document with 2500 citations on webpages. The paper just came from dedicating time to work on a non-academic journal. This type of document has a technical, scientific section forming the majority of the text. However, there is a less technical, four-page summary and a one-page executive summary for policy makers to take away the key messages, so it really is tailored for different audiences. The great thing about this type of document is it builds your reputation meaning people now approach us, and has led to collaborations in terms of both policy and fundamental chemistry. Are there any other upcoming policy documents or research you can talk about? We are writing a new white paper as the follow-up to our green economy paper, as it is now six years old and the landscape has changed. The research needs an honest and fair appraisal of the strengths, and importantly limitations, of using CO2. Our goal at CO2Chem is to take the middle ground and accept the limitations. The new white paper will be more inclusive looking at the whole carbon economy from multiple perspectives across physical and social sciences. It sounds nice and interdisciplinary. Yes and that is key! Funding agencies don’t want to see bubbles with labels like ‘I am an inorganic chemist’ or ‘I am a chemical engineer’. They want physical sciences working with social sciences with research, looking at, for example, the social impact of scientific research. In addition to research challenges, there are other challenges, including student recruitment. I was wondering if there were any upcoming changes that you could discuss. As I’m sure you’ve heard, there is a general decline in admittance to science and engineering subjects at universities. There are many factors that have likely led to this situation but likely student fees played a big part. But most importantly, how are we going to address it? We are going to make our course the best course in the country. We are going to make it a department where people want to come and work and study by offering excellent teaching and facilities. Research is great for an institution’s reputation, but students are the life blood of the department, so we must give that a high priority. I saw online that you had a stint as an EPRSC senior media fellow could you tell me about that? Yeah! Tony Ryan did the first one and then Noel Sharkey in computer science did the second doing Robot Wars, where he was one of the judges. I did mine on science and engineering in sport and then science and engineering in the kitchen. It was great, working with radio and TV and film producers. It led to me becoming a film producer making my own films, but unfortunately I don’t have the time any more. Do you have any other interests outside of chemistry? Well, one positive from film producing was that I started writing my own music to overcome some licensing issues with using music in films. This led me, a few Christmases ago, to build a recording studio in my house. I currently have 3 guitars, an electro-acoustic base, a cello, a violin, an electronic drum kit, digital grand piano, 2 synthesisers, and various other pieces of equipment. I now do my own multi-tracking for soundtracks. It’s both my hobby and method of relieving stress. Thank you for your time, Peter.
The University of Sheffield || Resonance Issue 8
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Feature
Smartphones: Behind the Screen By Beth Crowston
T
he number of smartphone users has increased dramatically in the decade following the release of the first iPhone. From an initial market of 122 million buyers, there are now an estimated 2.3 billion consumers worldwide; set to rise to over a third of the global population by the end of 2018.1 The actual number of handsets in circulation exceeds this even further, as people update their mobile phone to keep up with improving technology and tuck old handsets away in a cupboard to be long forgotten about. But how much do people know about the chemical complexity of the gadget in their pocket, and are there enough resources to keep up with the ever-increasing demand?
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What makes a phone smart? There are 83 stable (non-radioactive) elements on the periodic table and at least 70 of them can be found in varying amounts in an average smartphone. This equates to 84% of all the stable elements! Of these, 62 are metals; with copper, gold, platinum, silver and tungsten featuring predominantly, as these metals make up the main micro-electrical components as well as the wiring and solder. However, it is thanks to the rare-earth metals that smartphones have many of their ‘smart’ features. Of the 17 rare-earth metals, only element number 61 (promethium) cannot be found within a
smartphone due to its radioactive nature. Praseodymium, neodymium and gadolinium all aid the communication features through the speakers and microphone, and dysprosium, terbium and neodymium all assist the phone’s vibration function. The remaining rare-earths are used to produce the vivid colours in the screen and reduce UV light penetration into the phone. But how abundant are these elements? And how easy are they to extract? How rare are the elements? The rare-earth metals are actually adequately prevalent in the earth’s crust; the main issues occur because trying to extract them is
Feature Insight extremely difficult, time-consuming and costly to mine. However, the supply of the metals is finite, and once they have been used there is currently no suitable replacement. Unfortunately, recent statistics reveal that around only 10% of unwanted handsets are recycled, as many go forgotten at the back of a drawer or are simply just thrown away. This is a cause for concern, as it is predicted that in 20-30 years’ time we may not have access to the supply of these useful metals. One million recycled mobile phones could liberate nearly 16 tonnes of copper, 350 kg of silver, 34 kg of gold and 15 kg of palladium, and so the task of recovering these metals is one worth undertaking. But how easy is it to extract and separate the metals for reuse in a new handset? Recycling smartphones Most of the mobile phones that do make it to the recycling bin are
exported to countries such as China, where they are chemically broken apart to get at the valuable contents. However, the recovery processes used are not responsibly operated. A town in south-eastern China called Guiya has the largest volume of mobile phone waste in the world, which has led to the residents having health problems, as well as the soil, rivers and air becoming polluted with highly toxic chemicals such as lead, arsenic, mercury and chromium.
This is an unlikely solution to the issue, however, due to how quickly technology is advancing. Even looking for potential alternatives has bleak prospects as substitution is very difficult and the replacement metals may still have supply issues eventually anyway. Another hopeful avenue for recycling electronic waste is using hydrometallurgical techniques that can be housed in a shipping container and transported wherever necessary. However, this technology has yet to be applied to smartEven countries that try to respon- phones. sibly recycle smartphones on their own land such as Australia, face Although we don’t have an ideal problems such as the high costs solution right now, a project called of industrial smelting and the en- the Critical Raw Material Recovvironmental implications of using ery in the EU is working towards harsh chemicals. So is there a bet- collecting particular resources ter solution to the problem? that are economically important including the rare-earths, and so What can we do? a responsible answer to our recyIn an ideal world, smartphone cling needs may soon be found. consumers wouldn’t update their handset every 11 months and there 1. bit.ly/2oUFshU would be less of a demand on the 2. bit.ly/1uXnrXo resources in the first place.
Elemental Factfile: Gold By Josh Nicks
G
The first pure gold coins were minted by Croesus, the King of Lydia, Gold is the most malleable and during 561-547 BC. ductile of all metals, which is the reason we are able to easily make After the ancient era, most gold gold leaves – 1 gram of gold can came from the Aztecs or Incas, be flattened into a 230 atom thick and then the Spanish and Portu- sheet. The reason you hear of piguese brought this to Europe in the rates biting gold isn’t because 16th century. Major gold rushes they’re tough, it’s because gold is took place in the 19th century, in so malleable teeth can dent it, uncountries such as Australia, New like counterfeits. Egyptians made Zealand, Brazil, Canada, South Af- a huge variety of décor out of gold rica and the US, as miners sought - King Tutankhamun’s coffin conto claim their fortune. Gold rushes tained 112 kg of gold. An estimatsparked huge amounts of immigra- ed £585 trillion worth of gold, 20 Probably one of the most estab- tion and globalisation, and are the million tons, is found in the world’s lished uses of Gold was its use in reason that states like California oceans, with one litre of seawater the first major currency systems, were settled, as newly mined gold containing approximately one 13 provided a great economic boost. billionth of a gram of gold. which began in ancient Egypt. old’s name comes from the Anglo-Saxon word for the metal, while the symbol, Au, derives from the Latin ‘Aurum’ or ‘shining dawn’. Gold forms group 11 of the periodic table with Silver and Copper – these were three of the first nine elements known to ancient man, as they can be found naturally pure. Gold is known as the most noble of the noble metals, which are resistant to corrosion and oxidation, and it does not react with most acids or bases.
The University of Sheffield || Resonance Issue 8
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News
The Department of
S
heffield Chemistry had another busy year in 2017. Throughout the year, the department has played host to many events and distinguished guests, alongside the education of several hundred undergraduate chemists and the continuing research of the community of postgraduates, postdoctoral researchers and academic staff. The year began with several staff promotions, with Simon Jones, Oleksandr Mykhaylyk and Sarah Staniland being promoted to Professor, Senior Research Fellow and Reader respectively. February saw the first ChemSoc lecture of the year, delivered by MasterChef contestant Stuart Archer (right), a postdoctoral research fellow in the Thomas group, on culinary chemistry with free samples! The Stirling Lecture Series, allowing members of the department to see what research academics do outside of teaching, was also launched in February with the inaugural lecture given by Prof. Stirling himself. In March, the University celebrated International Women’s Day by commissioning several portraits of women who form part of the University community. One recipient was Pauline Boulding, the department’s long-standing provider of tea and coffee in the common room until her retirement in 2015. Around the same time, Sarah Staniland (left) was awarded the 2017 Suffrage Science Award for her achievements towards the promotion of women in science. March was also cause of celebration and appreciation for two long-serving members of staff, Harry Adams (Manager for X-ray crystallography) and Elaine Fisher (Postgraduate Recruitment Administrator) who retired at the end of the month after a total of 91 years’ service between them! In May, two members of staff received awards in recognition of their work. Julia Weinstein (left) was awarded the RSC Chemical Dynamics Award for her work in photoinduced charge transfer and control of reaction pathways using IR radiation. Meanwhile, Julie Hyde (right) received a Senate Award for Sustained Excellence in Learning and Teaching, in recognition of her efforts both in Sheffield and in China as part of the Nanjing Tech University/ University of Sheffield joint degree programme.
Harry Kroto was fondly remembered on the annual Kroto Day, held in June following his death in 2016. The day involved Year 7 students from Chaucer Academy in Sheffield watching a presentation prepared by Sheffield Chemistry PhD students on the measurement scales used in science, and took part in practical sessions including the synthesis of polymer slime! Later in June, Steve Armes (right) was awarded the European Colloid and Interface Science (ECIS) Award, sponsored by Solvay, for his work on design of block copolymer nanoparticles. Steve received the award after being nominated by colleagues from the ECIS.
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Chemistry in 2017
News
By Zoe Smallwood
Julie Hyde was presented with her Senate award (see above) at July’s graduation ceremony, alongside the year’s cohort of graduating chemists. The ceremony also hosted a distinguished Sheffield Chemistry Alumna- Helen Sharman, the first British person in space, who was receiving an honorary Doctor of Science degree. Helen gave a speech to the graduating class and took the time afterwards to meet members of Resonance in a follow-up to an interview she gave to Resonance the previous year. Alongside the departure of our most recent graduates, July also saw the retirement of another long-serving staff member, Dr Ed Warminski, who oversaw the undergraduate teaching laboratories for 25 years, after first coming to Sheffield to complete an MPhil degree in 1990! Professor Peter Styring was appointed as the latest Head of Department in July, following the departure of Mike Ward to take up the role of Head of Department at Warwick University. More awards followed in August and September for Sarah Staniland, Julie Hyde, Dan Jackson and Sophie Greaves. Sarah was awarded the Wain Medal for her biochemical research, which involves the presentation of her work in an award lecture, whilst Julie Hyde was given an Outstanding Service Award by the RSC for her service to the RSC as well as local, national and international chemistry. Our talented glassblower Dan Jackson was awarded a Literary Award from the British Society of Scientific Glassblowers at their annual symposium in September for his article about the Murano Glass Museum in Venice. Recent MChem graduate Sophie Greaves (right), now a PhD student in the Harrity group, had her 4th year MChem thesis ‘highly commended’ in the 2017 Undergraduate Awards. This puts her research, completed in the Coldham group, in the top 10% of research submitted to the Chemistry and Pharmaceutical category. During October, Harry Kroto was commemorated by the refurbishment and reopening of the department’s Schools Laboratory as the ‘Kroto Schools Laboratory’, and a donation by his wife Lady Margaret Kroto to establish of the Kroto Family Education Foundation. Both of these will enable Harry’s legacy to be continued through the education of young people and the public. Prof Armes received another award in November in the form of the Macro Group UK Medal for Outstanding Achievement, in recognition of his internationally-renowned contributions to polymer science. December saw several Graduate Teaching Assistants (GTA) achieve professional recognition. Beth Crowston, Dave Griffin and Zoe Smallwood (right) were appointed as Fellows of the Higher Education Academy (FHEA) in recognition of their efforts in their teaching and learning activities. The year was rounded off with Anthony Meijer being promoted to Professor in Theoretical Chemistry at the beginning of 2018. Acknowledgements: Joe Clarke and the Chemistry Publicity Team
The University of Sheffield || Resonance Issue 8
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Students
Year in Industry: AkzoNobel By Nara Vasa
L
ast year, I completed my year in industry with AkzoNobel in the Interior Wall Paints division, working with the UK and Ireland product development teams. I was one of twelve chemistry students hired to work in their research and development programme. I chose an industry year as I wasn’t certain whether I wanted a career in chemistry and had no real idea of what working in the chemical industry entailed. This was an opportunity to discover whether I would enjoy working in a laboratory environment full-time. AkzoNobel are most famous for their world-leading paint brand Dulux. I worked on a number of Dulux products throughout my year, innovating new paint formulations as well as tweaking existing ones to improve overall performance. The most common question people asked when told I worked for AkzoNobel was “Do you just watch paint dry all day?”. To which my answer was, of course not! Before my placement, I figured
Left: Nara and her colleagues in the lab. Right: Nara meeting Herbert the Dulux dog at Christmas.
that all white paint was the same. However, a lot of chemistry is involved in paint systems. By altering raw materials in different proportions, the opacity and the durability of a paint film change and in most cases the final colour of the paint system will too. Understanding how these alterations affect systems forms the basis of a job as a formulation chemist. On a day-to-day basis, I worked on numerous projects at one time, ranging from fixing quality complaints from consumers to cost-saving projects. Due to the high sensitivity of the formulations
our projects couldn’t be taken out of the office, which always gave us a good excuse to socialise after work. As well as learning a great deal from my experienced colleagues, a new product I was working on during my placement will be on the shelves for consumers to buy in early 2018, which will act as a permanent reminder of my work! I would definitely recommend an industry year to anyone thinking about applying. It can really help in deciding what you want or don’t want to do after you graduate and will give insight into the chemical industry in particular.
SURE Scheme: Armes Group By Sam Harrison
I
n 2016, I applied to the Think Ahead SURE scheme for a research placement during the summer. I was selected and offered the chance to work for Dr Matthew Derry, a member of the Armes Research Group. The project involved synthesis of block copolymer nanoparticles via polymerisation-induced self-assembly (PISA), and evaluation of their use as oil thickeners. The particular aim of this was to tackle the real-world technical challenge of thickening engine oil at high temperatures, which would increase engine durability.
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Work prior to this showed a unique high-temperature oil thickening mechanism, which occured due to a morphological transformation of the nanoparticles from vesicles to worms.1 Using this, it is possible to use thinner motor oil which would improve fuel efficiency at lower temperatures. Then, once the oil thickens at high temperatures, the engine parts become better lubricated and thus more durable. However, this process is currently irreversible, so the focus of my project was improving reversibility and increasing the extent of thickening.
The time I spent in the laboratory gave me the opportunity to engage in techniques that most undergraduates would not be able to at that stage, such as rheology, transmission electron microscopy, dynamic light scattering and gel permeation chromatography. I spent much of my time synthesising multiple block-copolymer nanoparticles with varying degrees of polymerisation as well as making reversible addition-fragmentation chain transfer (RAFT) agents. Actually undertaking research was a big change from undergraduate
Students labs, as you can’t know the outcome of an experiment for certain. For example, some vesicles I developed actually exhibited a greater extent of high-temperature oil thickening compared to prior work, but they too were irreversible. At the end of the project I attended a presentation day where members of the scheme gave talks and shared their research. It gave a great insight into different aspects of the work going on in the university and very useful presenting experience. For those interested in experience of working in a research environment, I must recommend the SURE scheme. It provided me with an opportunity to develop my knowledge beyond my course, and it was enjoyable to work with a wonderful group of people, who all have a passion for learning and research.
Figure 1. TEM image showing PSMA13-PBzMA96 vesicles undergoing a morphological transformation into worms at 150 ˚C, reproduced with permission from John Wiley and Sons.
Interested in the Think Ahead SURE scheme? Undergraduate students from any discipline, who are not in their first or final years of study, can apply for a summer placement based in the Faculties of Medicine, Dentistry and Health or Science, through a competitive application process. Successfully placed students get a taste of a career in a research environment by undertaking a 6-8 week project. See sheffield.ac.uk/rs/ecr/tasure for more details.
PepsiCo: Factfile By Jennifer Train
J
ennifer completed her year in industry in 2015 working at PepsiCo’s Beaumont Park facility in Leicester, and has written a factfile on some of their current targets regarding making snacks healthier. PepsiCo is a key player in the snack market; it is the second largest food and drink business in the world, with twenty-two of their brands each generating over one billion dollars in estimated retail sales every year. Of these, eight are snacking brands, including the famous Lay’s, Walkers and, who can forget, Doritos. Within PepsiCo, research and development plays an increasingly important role, with a focus on new product development and optimization. With obesity rates rising, a drive to create healthier snacks has begun, and doing so requires a unique
understanding of food chemistry. In 2016, PepsiCo issued a pledge to reduce the amount of saturated fat in at least 75% of their foods to less than 1.1 g per 100 calories. Many steps have already been taken to achieve this, largely targeting oil. So far, much of the oil in snacks has been substituted for healthier options like high oleic sunflower oil with very low saturated fat levels, but efforts have not stopped there.
such as Walkers Baked, is using emulsion technology. Through use of water-in-oil emulsions, oil content can be reduced by varying percentages of water in the emulsion, while not having to compromise on texture or flavour. However, the ‘crispiness’ of snacks depends heavily on moisture content, meaning water dispersed in these emulsions must be fully encapsulated and unable to destroy snack structural integrity - it is imperative that rheological and tribological (mouthfeel) properties are mainatained when using emulsions.
These are just a few illustrations of the ways companies like PepsiCo are utilising food chemistry to reduce saturated fat contents in their foods, whilst maintaining the same Another method of reducing oil taste and texture of the products amounts used for seasoning crisps, we all know and love. The University of Sheffield || Resonance Issue 8
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Feature
Plastic Money By Joseph Clarke
T
he money in our wallets is changing. The past two years have seen the conversion from old-fashioned “Paper” banknotes to modern polymer banknotes, with the introduction of the £5 note in September 2016 and the new £10 note in September 2017 - but what makes these notes better and what heightened security measures do they offer?
Banknotes have been a staple of our currency for over 300 years. Currency has always advanced with technology, and introduction of polymer notes is just the latest iteration. The old-fashioned banknotes are commonly referred to as “paper” - but this is itself a misnomer. Typical paper banknotes are constructed from 80% cotton paper, and cotton is comprised of the natural polymer cellulose. Polymer banknotes are typically made from polypropylene, a versatile polymer that is also used in various commercial applications such as food and DVD packaging. The difference in banknotes is in the process. The polypropylene used in banknotes is known as Biaxially Oriented Polypropylene or BOPP, indicating the process of stretching along two axes leading to a stronger, more durable plastic. These are expected to last 2.5 times longer than paper notes, and are also more resistant to dirt and moisture, looking new for longer.
birthed security devices known as OVDs or optically variable devices, which are now commonplace in any note and include effects such as holograms and colour changes. Australia were first to adopt the these in 1988, before they became known as polymer notes.
The new notes are said to be 2.5x more durable than paper notes, but this is only applicable to everyday wear and tear, polymers are by no means indestructible. Prof. Martin Poliakoff from Nottingham University, known for his “Periodic” YouTube videos, demonstrated two ways to destroy the £5 bankThe exact details of all security notes. The first was to submerge the measures in polymer banknotes note in liquid nitrogen, cooling to are understandably closely guard- -196 oC, before being struck with a ed secrets, but several OVDs are hammer. This freezes the polymer apparent to the naked eye. For strands which break on impact. instance, the gold leaf on the £10 note varies in colour according to the angle viewed, appearing gold in reflected light and green in transmitted light. The smoother surface also makes conventional security measures and printing easier; with holograms, microscopic lettering and images appearing sharper. Figure 2. The structure of nitrocellulose.
The Bank of England is only the latest to adopt polymer notes, with the initial research dating back to the 1960’s. Development of polymer notes is attributed to the Royal Bank of Australia and the Commonwealth Scientific and Industrial Research Organisation (CSIRO) combatting counterfeiters of the Figure 1. A group of polymer notes, with 10 AUD note in 1967. Their efforts chromatic effects in the crown image.1
The second method involved submerging the note in fuming nitric acid, which acts as a powerful cleaning fluid. After submersion, the ink was removed leaving a pure sheet of polypropylene, the exact size of the £5 note. As a control experiment, a paper note was also submerged in this mixture. This is where the chemistry gets explosive. Addition of nitric acid to cellulose leads to nitration of hydroxyl groups to create nitrocellulose (above), also known as guncotton - a low-order explosive with uses as propellants and in film.
Polymer banknotes have been introduced to modernise British currency. A new £20 note is expected to be introduced in 2020, and combined with a shift towards contactless payments, the way we spend our money is becoming more and more plastic by the year. 1. bit.ly/2v6PzyY
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2017 Nobel Prize in Chemistry
Research
By Zoe Smallwood
L
ast year’s Nobel Prize in Chemistry was awarded to three scientists who pioneered the work of Cryo-Electron Microscopy (CryoEM). Jacques Dubochet from the University of Lausanne, Joachim Frank from Columbia University and Richard Henderson from the MRC Laboratory of Molecular Biology in Cambridge were awarded the 2017 prize for using the technique for revolutionalising the way we image biomolecular structures in solution.1,2
Until the development of CryoEM, biochemists were faced with difficulties in actually observing what processes occurred in proteins, DNA and other biomolecules. Electron microscopy was often used, but required harsh conditions which can cause irreversible damage. X-ray crystallography provides high structural resolution with less risk of sample damage, but some biomolecules do not form in a crystalline state. As well as limiting the number of molecules that can be studied crystallographically, the requirement for single crystals often necessitates isolation from the systems the molecules are being studied in, meaning it can be difficult to study some heterogeneous structures as they exist in nature.
b Illustration, ©The Royal Swedish Academy of Sc1ences
Figure 1. Protein structures elucidated by Cryo-EM: a) A protein complex that governs the circadian rhythm. b) A sensor that detects pressure changes in the ear, allowing us to hear. c) The Zika virus.1
The Laureate’s work provides a compromise between these two techniques. Cryo-EM provides extremely high resolution (the current record standing at 1.8 Å3) without the need to remove samples from their environment, attempt crystallisation or place them in damaging conditions. Water is a key part of biochemistry, but the vacuum required for conventional electron microscopy often removed water incorporated within structures. This can lead to inaccurate results or different structures than would be observed in situ. Cryo-EM overcomes this thanks to the work of Dubochet, who realised that first firing the sample through a sample of ultracold (−190 °C) ethene did not make the water freeze into single crystals of ice, but instead became vitreous (non-crystalline).
Not only is this closer to the naturally observed state in biological systems, vitreous water barely diffracts the electron beam and so provides much clearer images than if ice crystals were present.2,3 The technique has revolutionised the field of biomolecular imaging, and has been used in high resolution characterisation of important biomolecules such as the Zika virus.4 It has even been predicted that as Cryo-EM advances, it will overtake X-ray crystallography as the preferred method of structural characterisation of biomolecules.5 Whilst crystallographic biomolecular imaging is not obsolete, the development of Cryo-EM has been dubbed “the beginning of a new era in molecular biology”, and the awarding of last year’s Nobel Prize reflects the great potential of the technique for the future.6
1. bit.ly/2y8zInm 2. Chemistry World, November 2017, 15-19. 3. A. Merk, A. Bartesaghi, S. Banerjee et al., Cell, 165, 2016, 16998-1707. 4. D. Sirohi and Z. Chen et al., Science, 352, 2016, 47-470. 5. E. Callaway, Nature, 525, 2015, 172-174. 6. W. Kühlbrandt, Science, 343, 2014, 1443-1444.
The University of Sheffield || Resonance Issue 8
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Crossword
Chemistry Crossword This crossword is designed to challenge even the most seasoned chemists, if you think you’ve completed it, take a picture and send it to chem-news@sheffield.ac.uk and we’ll announce you as the first chemistry crossword winner in the next issue.
Across
Down
1. Theorems used in density functional theory which relate to a system of electrons moving under influence of an external potential. (14) 4. French chemist known for his discovery of the role oxygen plays in combustion. (9) 7. The meaning of the abbreviation ‘z’ (as in, e/z isomerism). (8) 9. The process of applying a protective zinc coating to steel or iron. (13) 12. Element that shares its name with a superhero’s home planet. (7) 14. The surname of an ex-Sheffield chemistry professor, who won the Nobel Prize for his work on flash photolysis. (6) 15. An aromatic molecule consisting of a five-membered ring of nitrogen atoms. (9) 17. The element most commonly cited as being the densest known element. (6) 19. Glass bottle used to wash or dry gases. (8)
2. Principle that if two states occur consecutively during a reaction process and have nearly the same energy, their interconversion will involve only a small reorganisation of the molecular structures. (17) 3. The only non-metal liquid element at SATP. (7) 5. Flask named after the German chemist who designed it. (10) 6. An organic reaction that oxidises alcohols to carboxylic acids and ketones using chromium trioxide in sulphuric acid. (5) 8. One of the most recent elements to be discovered, named after an east Asian country. (8) 10. A crystal system consisting of a rectangular prism with lengths a, b, c where a=b. (10) 11. Isotope of hydrogen with a half-life of 12.32 years. (7) 13. Unit used to quantitate the pungency of spicy foods. (8) 16. A form of life notation for describing chemical species using short ASCII strings. (6) 18. A palladium catalysed cross coupling involving organostannaes. (6)
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Resonance NEEDS YOU!
Interested in writing for us? Thinking of a career in Scientific Communication? Have you enjoyed reading this issue of Resonance? We would love for you to get involved in our next issue! We welcome anyone interested in writing or researching articles, designing or contributing to our social media presence, regardless of experience or year of study. As a bonus, contributing to Resonance is HEAR accredited. If you are interested email the team at:
chem-news@sheffield.ac.uk
Don’t forget to follow us on Social Media to keep updated.
Resonance Contributors
We would like to thank the following students who have contributed to Resonance over the past issue and will graduate with HEAR accreditation: Hannah Winter Nara Vasa Sam Harrison Resonance could not exist without their dedication and hardwork. Special thanks go to Imogen Holmes, a local college student who had the initiative to contact us and write one of our feature articles.
Event and Seminar Listings Disorder in Inorganic Solids: Exploiting Multinuclear NMR Spectroscopy and DFT Calculations Prof. Sharon Ashbrook 22 February Simplifying Earth-abudant metal catalysis Dr. Stephen Thomas 8 March British Science Week 9-18 March Porter Symposium and Laser Lab Opening 14 March RSC Tilden Lecture 2017 Prof. Lucy Carpenter 22 March
Various nights out, guest lectures and non-alcoholic socials to be confirmed. More details can be found at: sheffield.ac.uk/chemistry/events
This Semester in Pictures