The Mole
... for anyone inspired to dig deeper into chemistry
Adventurous science
Experimentation and exploration go hand in hand as Zoë Fleming takes to
the field in the Arctic
Issue 02 | March 2013
In this issue
A magnificent
molecule
What do skin creams,
pretzels and fertilisers all
have in common?
Keeping fruit fresher
Find out how to stop your
bananas from going off
So you want to be a
chemist?
All about work experience
Super surfaces
that repel liquids
Cutting-edge chemistry
Cakes and bread
© ZoË Fleming
Avogadro's lab
looks at foams
High on a glacier in north-east Norway...
Not all chemists wear white coats. Some wear crampons
and glacier goggles and tramp around remote hillsides
with a camera, notebook, sample vial, pH paper,
penknife and battery-powered air pump in their
backpacks along with essentials for several weeks of
wild camping.
and a thirst for knowledge, you might discover a passion
for understanding the Earth and its environment.
Editor
Karen J Ogilvie
Arctic odyssey
Assistant editor
David Sait
Last summer, 60 ‘young explorers’ (aged 16–20),
14 leaders and 12 trainee leaders took part in an
expedition to Arctic Norway with British Exploring
There are still remote places in the world to explore and (BE, formerly British Schools Exploring Society, BSES).
investigate with science. You may picture Captain Scott
The party was divided into five groups concentrating
or other bearded men from the heroic age of exploration on specific science topics, linked to the expertise of
and science and think that was a bygone era. But
the science leaders. They carried out research in that
new discoveries are still being made, and we are still
discipline as they travelled around the area on foot,
best able to learn about our environment by sampling
setting up camps as they went. As an environmental
and testing it. If you are tired of sitting in a classroom
chemist working for the UK National Centre for
and preparing for exams and want to see what field
Atmospheric Science, I led the ‘atmospheric’ group,
scientists do, why not join a science expedition with
along with an atmospheric physicist (and science
British Exploring? If you have a keen sense of adventure teacher). We were trying to bring together a story about
ChemNet content
Francesca Burgoyne
Production
Scott Ollington and Emma Shiells
Publisher
Bibiana Campos-Seijo
The Mole is published six times
a year by the Royal Society of
Chemistry, Thomas Graham
House, Cambridge,
CB4 0WF.
01223 420066
email: [email protected]
www.rsc.org/TheMole
© The Royal Society of Chemistry,
2013. ISSN: 2049-2634
www.rsc.org/TheMole
Registered Charity Number 207890
The teams carried
out research as they
travelled around the
area on foot
© ZoË Fleming
we found their levels to all be very close to or below the
limits of what our kits could detect. The pH was also
at a safe level, between 5.5 and 6.5, much less acidic
than during the acid rain scare a couple of decades
ago in Scandinavia. Comparing our results with past
measurements from a nearby monitoring station
showed how pollutant levels in rainwater and in the
lakes, streams and soils have been dropping since the
late 1980s.
the weather and how pollution is transported to the
area; to carry out an environmental investigation of this
fragile remote environment; and to have a good oldfashioned adventure along the way.
Our experiments were designed to be portable and
easily carried from base camp to our many campsites
around the area – including up on the ice cap, over
1000 m above the fjords, and past fields of crevasses
(deep cracks in the ice). Improvisation is the name of
the game in these remote areas, so we made use of
any opportunity to monitor environmental variables
as we moved through the changing terrain. The young
explorers quickly developed useful skills, like always
having a bottle to hand to take samples for analysis
back at camp, along with a notebook and camera to
log the location. We wanted to merge environmental
chemistry monitoring with a feeling of environmental
responsibility, a ‘leave no trace’ ethic and also an awe
and respect for nature, while living in this wilderness
under the midnight sun.
Separating and analysing
all the different
greenhouse gases in
these arctic air samples
is done by gas
chromatography. The
mixture of gases is fed
into one end of a long
glass tube, lined with a
material that sticks to
some of the gas
molecules better than
others. An unreactive gas
like helium is pumped
down the tube, carrying
the sample gases with it.
As they travel along the
column, the gases are
separated out according
to how strongly they stick
to the lining. The ones
that stick least well come
out the other end first,
and can be fed into other
instruments for further
analysis. For example, a
mass spectrometer can
weigh the molecules very
accurately and determine
the ratio of methane with
14C in it to that with
normal 12C.
2 | The Mole | March 2013
Leaving the lush green valleys and boulder-strewn
mountain ridges behind for the snow fields and ice
on the Øksfjordjøkelen
glacier was always exciting
and an extra challenge
to our mountaineering
endeavours. It was also
a chance to do some
different science. We
compared the gritty snow
of the glacial moraine –
with large amounts of rock
and gravel dust covering it
– with the cleaner snow of
the ice cap. Passing melted
snow through a filter showed the amount and size of
particles on the snow surface. It was interesting to see
how even the clean snow left a visible spattering of fine
black particles on the filter paper. This darkening of the
snow decreases the albedo (the reflectivity of the snow),
which means it absorbs more sunlight, so the snow pack
warms and melts more quickly.
We carried out many tests on the water in the numerous
lakes, rivers and streams, using water quality testing
kits that revealed pH, as well as concentrations of
Another interesting find (worthy of more investigations)
sulfates, nitrates and nitrites, phosphates and ammonia.
was algae growing in channels and narrow funnels,
Comforting to us, but not a breakthrough scientifically,
where the dissolved nutrients in the meltwater drain
off the ice cap. We first noticed them as very localised
pink patches. The colour comes from a carotenoid
chemical – similar to the compounds that colour carrots
or tomatoes – which the algae produce to protect
themselves against the high levels of visible and
ultraviolet light that bear down on the ice cap 24 hours
a day in spring and summer. Filtering this snow showed
us these tiny red algae and the presence of other bugs
(even mosquitoes). We later found out that the local
reindeer were very keen on licking the ice for some
extra nutrients.
© ZoË Fleming
Testing kits revealed the
high quality of the water
Lab in a backpack
On the ice cap
Daily air sampling
Throughout the expedition we carried out meteorological
observations every morning and pumped samples of air
www.rsc.org/TheMole
© ZoË Fleming
What’s in
that balloon?
We also tested so-called ‘natural’ cosmetic products
– such as organic laundry soap and toothpaste – and
compared them with some chemically manufactured
soaps. The results showed us why we should be using
these natural products in the wilderness, as the nonorganic versions tested much higher in nitrates and
made the water considerably alkaline, while the natural
products did not affect the pH.
© sean crane
into special plastic bags that were sent for greenhouse
gas analysis using gas chromatography at Royal Holloway,
University of London, UK. Investigating the ever-increasing
methane levels in the Arctic helps us to understand its
sources and the release mechanisms. Tracking the 14C
isotope levels in the methane also gives us a clue to its
source. A long term greenhouse gas monitoring station
is being set up on the coast nearby and while we were
sampling, other scientists were taking air samples from
an aircraft that was flying between Sweden, Finland and
the Norwegian island Svalbard, so our daily ground-based
samples have been a useful addition to their database.
Carrying the battery powered pump up many a mountain
was source of great hilarity. For the good of science, we
whipped it out every morning – come rain or shine –
then carried three or four of the two litre air sample bags
back to base camp after each excursion, strapped to the
science leader's already overflowing backpack.
More than just weather
In combination with the glaciology, geology, marine
biology and geomorphology science groups on the
expedition, we worked on a river flow monitoring
experiment on the outflow valley from the glacier. We
measured the temperature and flow rates from all
the tributaries joining the river from the surrounding
slopes and ridges. This was a mighty task, showing the
immense quantities of water rushing down the steep
Exposing
ozone
© ZoË Fleming
Other experiments involved measuring ozone with ‘Eco
Badge’ test cards, which show the one hour and eight
hour average ozone exposure (again, all showing very
low levels). We also set up a British Antarctic Survey
ozonesonde probe, designed to be released from
helium balloons in Antarctica. The students saw the use
and running of small scale measuring devices, some
purpose-built and some commercial, all able to measure
meteorological and atmospheric chemistry.
The team monitored many
different environmental
variables
valley sides and groundwater channels in the area.
Wherever we could, we tried to overlap the science
themes to give our young explorers a sense of how
earth system science is a real mix of chemistry, physics,
biology, geology and geography.
Zoë Fleming is an atmospheric chemist at the National
Centre for Atmospheric Science, University of Leicester, UK
Acknowledgements
Visit www.britishexploring.org for more information
about future expeditions.
We would like to thank the RSC International Year of
Chemistry (IYC) funding to the Environmental Chemistry
Group (ECG) that paid for the instrumentation used on
the field trip and British Exploring for some fantastic
experiences for the leaders and young explorers. I would
also like to thank my fellow leader Sean Crane and the
young scientists themselves.
These 'Eco Badge' test
cards measure ozone
exposure, a major
component of air
pollution. Ozone is
created by sunlight
reacting with the nitrogen
oxides emitted by cars
and industry.
Sign up!
www.rsc.org/TheMole
© ZoË Fleming'
If you are interested in joining a British Exploring
project next year, either as a young explorer in the
summer holidays, as a gap year project, a university
science expedition or as a trainee leader (if you
are 18 or over) then check out their wide variety
of trips to Norway, the Himalaya, Iceland and the
deserts of Oman. If you sign up early, you can find
out more in the training weekends that prepare you
for the big expedition. Young explorers are helped
and encouraged to come up with original ideas for
fundraising for the trip and are given some preexpedition training. The society has left a legacy of
science projects in remote areas around the world,
and has worked with many scientists to bring back
good quality data, so if you know any keen scientists
to collaborate with, the society would love to hear
from you too. They would also welcome any keen
science teachers to apply as leaders.
Find out
more
Learn about using
Antarctic ice cores to
measure climate change
with this article from
Chemistry World:
http://rsc.li/XzcyKo
Fancy a trip to Norway,
the Himalaya or Iceland?
March 2013 | The Mole | 3
Magnificent molecules
Urea
Ian Le Guillou finds out what skin creams, pretzels
and fertilisers have in common
Urea was the first molecule from a living organism to be
synthesised in a lab. The honour for this achievement
goes to Friedrich Wöhler, who synthesised urea in Berlin
in 1828 by reacting silver cyanate and ammonium
chloride. As so often happens in these stories, Wöhler
never intended to make urea, but was actually trying to
make ammonium cyanate. However, the significance of
his discovery was so great that he is now
known as the father of organic chemistry.
highest percentage nitrogen content of solid fertilisers,
which means less weight is required and it is cheaper to
transport. The urea typically decomposes into ammonia,
which can be absorbed by plants. However, ammonia
tends to evaporate, reducing the amount of nitrogen
available in the soil. To avoid this, particularly during
the summer, farmers will spread the urea on fields just
before it is due to rain.
The ammonia can also be oxidised by bacteria
in the soil, creating nitrates. Nitrates are easily
Before Wöhler, it was still possible to get
absorbed by plants, but can be carried away
Urea
hold of urea but it doesn’t sound pleasant
in rain water, running off into nearby lakes and
– Herman Boerhaave purified urea from urine 100
rivers. This is a growing problem because it encourages
years earlier. Boerhaave’s work on urea was somehow
the growth of plants in the water, which can disrupt the
forgotten and 50 years later a method for purifying urea local ecosystem.
was rediscovered by French chemist Hilaire Rouelle.
Modern synthesis
Unfortunately, as it took two hundred years until
Since Wöhler, the method for synthesising urea has been
Boerhaave’s work was uncovered, confusion about who
adapted. The Bosch–Meiser process reacts ammonia
first discovered urea persists, although Boerhaave is
and carbon dioxide, under high temperature and
now slowly getting the recognition that he deserves.
pressure, to form ammonium carbamate which then
The human body produces urea from ammonia and
decomposes into urea and water. Even though this was
excess amino acids. Amino acids are usually used to
first developed in 1922, it still remains the standard way
make the proteins that we need to function. However,
of producing urea, thanks to the cheap reagents used.
ammonia is toxic, so it is vital that the body has a way to
get rid of it. Ammonia is produced naturally in the course Urea can be reacted with formaldehyde or nitric acid to
create a range of other materials that can be used to
of metabolising food, but if it is allowed to accumulate
in cells it would raise the pH to toxic levels. Even though make resins, plastics and explosives. However, it also
has a wide range of uses including a skin softener in
it costs energy to do so, ammonia is converted to urea,
which is practically harmless and can be removed easily cosmetic creams and colouring for pretzels.
through urine and even a little through sweat!
There are few molecules that have such an important
Efficient fertilisers
place in chemical history. The story of urea is nearly 300
Industrially, 100 million tons of urea is synthesised
years old, from rather smelly origins through to fertilising
every year. So what is it all used for? Well, 90% goes
the world’s crops. Its synthesis may have been a lucky
into fertilisers, providing an essential source of nitrogen accident but it laid the foundations of modern-day
for crops to grow as quickly as possible. Urea has the
organic chemistry.
A little accident
Urea is used to add colour
to pretzels
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4 | The Mole | March 2013
www.rsc.org/TheMole
Secrets of the trade
Keeping fruit fresher for longer
You may have come across the old trick of putting a
banana in a bag with unripe tomatoes to help them
ripen more quickly. Have you ever thought about how
this works?
eaten. Suppliers are testing plastic bags impregnated
with potassium permanganate. The plan is that
customers can wrap fruit up in the bags and it should
stay fresher for longer.
Ripening process
A quick web search will reveal all sorts of 'fruit keeping'
devices, many of which make use of zeolites. Zeolites
are a naturally occurring material with many household
uses (eg washing powders and cat litter). They consist of
an extended microporous crystal structure that readily
adsorbs gases and ions. Cartridges containing zeolites
soaked in potassium permanganate can be fitted into
the base of fruit bowls and storage boxes to keep fruit
fresher for longer.
Certain fruits such as apples, apricots, tomatoes and
bananas are known as climacteric fruits. Climacteric is
the name of a stage in the fruit ripening process when
cell respiration rises and ethylene gas is produced. This
leads to changes in pigment (eg banana skins turning
black) and an increase in sugar levels. This stage marks
the peak of edible ripeness and from that point the fruit
will start to 'go off’.
Now that you know some of the science you can make
more informed decisions when choosing your ‘fruit
keeping’ devices!
Find out more
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Learn more abou
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http://bit.ly/14
Reference
1. Chemistry World, June 2012, p4 (http://rsc.li/XsT6Af)
© vario images GmbH & Co.KG / Alamy
Ethylene produced by bananas can cause other
climacteric fruits (such as oranges and grapes) nearby to
ripen more quickly. Even non-climacteric fruits (eg some
melons) can still have active ethylene receptors and so
may also be affected by nearby fruit, even though they
don't produce ethylene themselves.
Ecuador is the world’s
largest exporter of
bananas – 5.2 million
tonnes every year. The UK
imports 1 million tonnes of
bananas each year.
© North Wind Picture Archives / Alamy
Jonathan Hare investigates how to stop his bananas
from going off
Did you
know?
Freshness in transit
When fruit is transported in bulk, the air is often
monitored for ethylene to check the state of the
produce. The ventilation and temperature can then be
regulated to try and prolong the freshness of the fruit.
Ethylene levels for bananas and avocados need to be
kept between 0.1 to 1 ppm. Monitoring at this level
is a costly and time consuming process. Recently, a
relatively simple nanotube-based ethylene detector has
been developed that should make monitoring much
cheaper and easier.1
If you could absorb the ethylene produced, would it
prolong the life of your fruit? In industry, potassium
permanganate is used to achieve this. The complete
reaction may be complex, but essentially ethylene is
oxidised to ethylene glycol (in some cases it may even
be oxidised to CO2):
2KMnO4(s) + 3C2H4(g) + 4H2O(l) →
2MnO2(s) + 3CH2OHCH2OH(aq) + 2KOH(aq)
Stay fresh solutions
When we buy fruit, we obviously want to keep it fresh for
a reasonable length of time. It’s a well known fact that
mountains of fruit are thrown away before they can be
www.rsc.org/TheMole
March 2013 | The Mole | 5
© the hitman
Avogadro’s lab
Foams
Toothpaste for
elephants?
‘Elephant’s toothpaste’ is a
spectacular demonstration
that generates a huge
amount of foam in no time
at all – take a look on
YouTube:
http://bit.ly/149oMja
Stephen Ashworth tells us about a conversation
between Avogadro the Mole and his friend Bob…
Cheers!
Some people get all the
fun! Find out about the
team whose job it is to
study the physics and
chemistry of the bubbles in
champagne:
http://rsc.li/M6n2dY
‘I say, Avogadro,’ said my friend Bob, ‘the cappuccino
foam here is magnificent.’
‘I couldn’t agree more,’ I replied, as we found seats in
the bustling coffee shop.
‘It’s such a shame that you only get foam on a
cappuccino and in a washing-up bowl.’
‘On the contrary, dear Bob,’ I corrected, ‘but what we
should do first is decide what we mean by foam.’
‘Go on then, what is foam?’ challenged Bob.
© shutterstock
‘A foam is a series of pockets of gas trapped in either
a solid or a liquid (bubbles). There are lots of different
foams all over the place.’
‘Well really, Avogadro,’ said Bob indignantly ‘give me an
example.’
6 | The Mole | March 2013
Cushions, sandwiches and volcanoes
‘Let’s look at the chair you are sitting on – it probably
has foam rubber in the cushion.’
‘Of course!’ exclaimed Bob. ‘I should have thought of
that, but surely there aren’t many others?’
‘Think about the sponge cake you’re eating – that’s a
foam. The whipped cream in the middle is a foam too.
Those sandwiches on the counter are made of bread,
another foam.’
‘Well I never,’ said Bob, ‘I’d never thought of it like that.
Does that mean that your meringue is a foam too?’
‘That’s right.’ I replied. ‘There are also foams in nature.
A sponge is foam – air pockets trapped in a solid much
the same as pumice – the rock from volcanoes. You find
www.rsc.org/TheMole
Egg white on the left and washing
up liquid foam on the right
foams in plant stems and some insects use foam to
protect their eggs.’
same, does it?’
‘Yes, that’s right,’ I
confirmed. ‘Then you take
your sample and ideally
Surface tension
put it in a very clean,
‘What we need to make a foam is a substance that helps
narrow, straight-sided
to stabilise a surface. If you think about a single soap
transparent container. A
bubble, it’s just a thin film of water with two surfaces –
measuring cylinder would
inside and outside.’
be perfect, but as long as
the vessels have the same
‘So what will stabilise such a large surface?’
shape and size the results
‘Any molecules that collect at the surface of a liquid
will be comparable.’
and reduce the surface tension will help make a foam.
‘Can I use glasses?’
Surface tension is the force that makes drops of liquid
spherical – the molecules in the liquid don’t like to
‘Yes, if they are all the same.’ I said. ‘Then you blow
be at the surface, so the drop forms the shape with
into your sample until there is enough foam to fill
the minimum surface area possible. The substances
the container. If you can’t even fill the container you
that collect at the surface are known as surface active
know your foam is not stable. As gravity makes the
agents, or surfactants.’
liquid drain out of the bubbles to the bottom of the
foam, some of them will burst. The speed the foam
‘That’s fine, but what sort of molecules make good
drops in the container gives an indication of the
surfactants?’
stability of the foam.’
‘Washing-up liquid is a good example. It’s made up of
‘What can I use as a sample?’
molecules that have one end that likes to dissolve in
water and one end that doesn’t.’
‘You can use anything that will make a foam. I tried
it first with a teaspoon of washing-up liquid in about
‘Wait… wait… that means that one end is hydrophilic, it
100 cm3 of water, and then with some egg white
likes water, and the other end is hydrophobic, does it?’
dissolved in about the same amount of water. The
said Bob, excitedly.
proteins in the egg white act to stabilise the foam.’
‘That’s correct,’ I replied, ‘so the molecules collect at
Is it a fair test?
the surface with the hydrophilic end in water and the
‘Egg white will have water in it too, so isn’t it hard to
hydrophobic end sticking out. The result is a lower
devise a fair test for this?’ asked Bob, frowning with
surface tension, which stabilises the liquid foam.’
concentration.
‘What makes a foam then?’ asked Bob.
Bubbles
In 1999 the world record
for the most people
simultaneously blowing
bubbles was set in
London. 23 680 people
gathered to blow bubbles
for one minute.
Try it yourself – testing stability
‘Are some foams more stable than others?’
‘Oh yes.’
‘Can you test the stability of a foam?’
‘Well, there is a nice little experiment that you can
do when you get home,’ I said, ‘first you have to find
something that will make lots of little bubbles. I did this
by tying or gluing a piece of foam rubber to the end of
a straw.’
‘That helps to make lots of small bubbles that are all the
www.rsc.org/TheMole
‘That’s a very good point – I assumed that the egg
white was around 90% water and used half water
and half egg white, but even that has its problems.’
‘I think I will go home and try it out myself!’ said Bob
eagerly, as he stood up to leave.
‘A least we know that the milk foam is pretty stable,’
he chortled
Find out more
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‘How?’ I asked, puzzled.
‘You’ve still got some on the end of your nose!’
March 2013 | The Mole | 7
Cutting-edge chemistry
See it
work�
Watch beads of solution
roll around and observe
how it resists attack from
acid and base:
http://bit.ly/15p7z5S
© american chemical society
The super
material
consists of a
stainless steel
mesh coated
with a layer of
polymer beads
8 | The Mole | March 2013
A material that is equally good at repelling water, oil,
concentrated acid and alkali solutions, and non-Newtonian
fluids like polymer solutions has been created by chemists
in the US. This chemical resistance combined with the
simple, scalable production process makes it promising for
protective and self-cleaning surface applications.
© american chemical society
See droplets of liquid and
jets of fluid bounce off the
superomniphobic surface
in this YouTube video.
Super surface repels non-Newtonian
fluids
Anish Tuteja from the University of Michigan in Ann Arbor
explains that while a lot of effort has been directed towards
creating ‘self-cleaning’ superomniphobic surfaces that
repel both oily and water-based liquids, less attention has
been paid to non-Newtonian fluids.
Honey, custard and polymers
Viscous substances like custard, honey and solutions
containing polymers change the way they flow depending
on the forces applied to them. They can also absorb a lot
more energy by deforming when they hit a surface. The
deformation and flow of matter is known as ‘rheology’.
Adding 0.2 wt% of a polymer to water can make a droplet
stick to a surface where pure water droplets would bounce
off, Tuteja explains. ‘But in this case [...] we can still get
droplets or jets of these solutions to bounce off’.
‘Normally, when people talk about superhydrophobic or
superomniphobic surfaces, they talk about wetting, which
is a measure of the shape that droplets make on the
surface and their contact angles,’ says Sergiy Minko, who
researches smart polymer materials at Clarkson University
in Potsdam, US.
less impact,’ he adds, which is why the surface can repel
Newtonian and non-Newtonian fluids equally well.
The surfaces are also highly resistant to chemical attack.
Tuteja and his group covered one side of aluminium
plates with their material and dunked them into baths of
The crucial aspect of Tuteja’s surface, Minko says, is that it
concentrated hydrochloric acid and sodium hydroxide. The
has a very low wetting hysteresis, which means that as a
droplet rolls over the surface, the contact angles at the front uncoated sides of the aluminium were quickly attacked, but
and rear of the droplet are almost the same, so the droplet the coated surfaces were completely protected.
does not deform very much. ‘This means the rheology has
Pockets of air
All of these properties stem from two aspects of the
material’s construction, Tuteja explains. The material is
based on a fine stainless steel wire mesh. This is coated
with a layer of polymer beads, made from a mixture of
polydimethylsiloxane (PDMS) and fluorodecyl polyhedral
oligomeric silsesquioxane (POSS). The roughly spherical
shape of the beads gives the surface the geometry required
to make it superomniphobic and also means it traps a layer
of tiny pockets of air, which prevents the acid or base from
coming into contact with the surface, so it can’t react. The
fluorinated POSS molecules also migrate to the surface of
the beads, lowering the surface energy and enhancing the
chemical resistance. Phillip Broadwith
www.rsc.org/TheMole
Platinum plating at the flick of
a switch
Atom thick catalytic layers of platinum can be
deposited on surfaces from solution rapidly and
cheaply thanks to a new technique developed by
scientists in the US.
atoms are deposited first at steps or defects on the
surface. ‘But platinum is happier growing on platinum
than it is on gold,’ says Moffat, so you end up with islands
that eventually join up into relatively thick, lumpy layers.
Platinum films are used as catalysts in devices such
as fuel cells, as well as in microelectronics and various
other applications. Because of the rising price of
platinum and the interesting properties of very thin
films, it is desirable to make these films as thin as
possible, explains Thomas Moffat from the National
Institute of Standards and Technology in Gaithersburg,
who led the project.
Reversing the polarity
Abandoning tradition
Atomically thin films of platinum can already be made,
Moffat acknowledges, but these techniques involve
expensive high vacuum chambers and each layer forms
quite slowly. ‘We’re essentially using beaker chemistry
and can lay down a monolayer in under a second,’
Moffat says, ‘so from an engineering perspective it’s
much simpler.’
As part of their investigations, Moffat’s team tried
cranking up the voltage. ‘We went right to the threshold
of when you start reducing the protons in solution into
hydrogen gas, which is not normally what you’d want to
do,’ he says. Instead of getting a very thick film of metal
laid down, they got a single atomic layer of platinum,
capped with a layer of hydrogen atoms. Switching briefly
to a positive potential oxidises the hydrogen atoms off
the surface, leaving the platinum ready to add another
layer if needed.
This, says Jay Switzer from Missouri University of
Science and Technology in Rolla, US, is the biggest
advantage of the technique. ‘In one beaker, just by
pulsing the potential back and forth, you can put down
one monolayer at a time. So if you wanted to look at
properties of a material as a function of thickness, you
But to get a smooth, thin layer of platinum atoms on
can grow anywhere between one and several layers
their surface, the team had to abandon traditional
electrodeposition techniques. Normally, Moffat explains, fairly easily.’ This kind of investigation will be particularly
deposition is done very slowly. The item is immersed in a useful for people working on catalysts and magnetic
bath containing a platinum salt and a very small potential materials, where the properties of thin film materials can
vary considerably. Phillip Broadwith
is applied. The platinum complex is reduced and metal
Electrochem
istr y
What does
an electroch
emist
do? How do
you becom
e one?
Take a look
at this profi
le of
electrochem
ist Katherin
e Holt
from Chem
istr y World:
http://rsc.l
i/TRnXdi
Find out more
t
st and resistan
Medicine, cataly
t
ou
ab
arn more
to corrosion – le
arkable
platinum’s rem
this ar ticle from
ith
w
s
tie
er
prop
emistr y
Education in Ch
magazine:
hS7h
http://rsc.li/Xd
© science/aaas
Scientists can
build a platinum
coating one
layer at a time
by pulsing
the electrode
potentials
Mole
You can download The Mole at www.rsc.org/The
and copy it to use in schools
www.rsc.org/TheMole
March 2013 | The Mole | 9
RSC ChemNet Events
Dates for
your diary
E ngaging with the UK
parliament
19 March 2013 18:00–20:00
Liverpool
Hear Chris Blanchett,
Parliamentary Outreach officer
for the north-west, talk about
how parliament works.
http://rsc.li/14dKO3z
L ook what chemistry has
done for me
27 March 2013 13:00–15:00
London
Come along to The Royal
Veterinary College to find out
more about careers in chemistry.
http://rsc.li/Wm0zQ9
Quotient site visit
19 June 2013 12:30–15:30
Cardiff
A chance to visit the world’s
largest radiochemical facility
and find out how radiolabels are
used in drug discovery.
http://rsc.li/Wm0sE4
Meet the Universities
29 June (Leeds) and
6 July (London) 2013
10.00–12.30 and 13.30–16.00
If you are considering a degree
in the chemical sciences, then
this is a fantastic opportunity
for you to talk directly to staff
and students from many of the
UK's universities.
http://rsc.li/mtu
10 | The Mole | March 2013
Francesca Burgoyne from RSC ChemNet takes a look at
why you should get some work experience and how to
go about finding a placement
If you think you’d like a job that involves chemistry, it’s
a good idea to get some work experience in an industry
that uses the chemical sciences.
© the Nuffield foundation
L ook what chemistry has
done for me
14 March 2013 18:30–20:30
Cambridge
A great opportunity to learn
more from real chemists about
possible career options in
chemistry, with free buffet.
http://rsc.li/14dJUEa
So you want to be
a chemist?
Work experience can give you an insight into how
science can be used to solve some of the problems that
society faces. It’s an opportunity to find out what you
are good at, to learn new skills, to find out if a particular
job suits you and maybe put some of the chemistry
you’ve learnt into practice.
Do I really need work experience?
Even if you already know you’d like to be a chemist,
there are lots of reasons why getting work experience is
a good idea.
It puts you ahead of the game and shows that you’re
keen and committed when you’re applying for university
or your first job. If you’ve taken the time to find and
complete a work placement, then admissions tutors and
potential employers know you are serious.
Recent studies have shown that university graduates
are more likely to be employed if they already have
work experience, often because they are taken on by
the companies that gave them the placement in the first
place. Companies like to employ people they already
know they can trust.
Your application for the next stage in your career will
be stronger. Your CV will stand out, and in interviews
you will be able to talk about the skills and experience
you’ve gained. If you do well on your placement,
you should be able to get a job reference from the
organisation you work for.
So how do I get it?
First, think about what you want to get out of a placement.
What are you interested in? Do you want to get some
experience of a particular sector or industry? Do you want
to know what it’s like to work for a large company?
The internet is the best place to start when looking for
companies in particular industries, but just typing in
‘work experience chemistry’ won’t yield the best results.
It does require some digging to get a good placement,
but the payoff will be worth it.
Some places to start looking:
Family and friends – it’s all about who you know. If
you have a great aunt who happens to be the chair of a
multinational pharmaceutical company, give her a call!
Local companies – find out what chemical
companies are in your area and whether they have
work placement schemes.
Find out what other students have done – your
school careers service will be help out, or speak to
students in the years above you.
University research labs – some universities are
able to take students for short placements in their
research labs.
Try your RSC Local Section – RSC members have a
wealth of experience and it’s all connected to chemistry.
They might be able to put you in contact with someone
with a placement opportunity (http://rsc.li/14nVeP0).
Nuffield Research placements – each year the
Nuffield Foundation provides over 1000 students the
opportunity to work alongside professional scientists
across the UK (http://bit.ly/X8l43Y).
www.rsc.org/TheMole
Oliver Holton
Graduate trainee at Johnson Matthey
Chemistry can take you around the world and into a
range of careers. Ian Le Guillou finds out about Oliver
Holton's journey through chemistry.
Since first visiting China for the International Chemistry
Olympiad in 2005, Oliver has been fascinated by
the country and its culture. Thanks to his chemistry
knowledge, he has been able to enjoy living and
working there, and will be returning again soon.
Pathway to
success
2012–present
Graduate trainee,
Johnson Matthey, Royston
2011–2012
Chemistry tutor,
Manchester
2009–2011
Lecturer, Tsinghua
University, Beijing, China
2005–2009
MChem, University of
Oxford
2003–2005
A-levels in chemistry,
biology, maths and French
at Manchester Grammar
School
While studying for his chemistry degree he taught
himself Mandarin Chinese, and after finishing university
he went to Beijing to teach English to science students:
‘I taught classes to science majors with the aim of
improving their ability to present their own research,
read research papers and write their own.’
Chemical language
‘I taught quite a lot of organic mechanisms and how to
describe them in English, which is surprisingly tricky...
It's that kind of language which is hard to get from a
normal English teacher. So my advantage was that I
had my chemistry background, as well as being able
to speak English, and that's why I was employed – the
chemistry background clinched it.’
Determination
Graduate trainee
Oliver is now a graduate trainee at Johnson Matthey,
a large chemicals company, in Royston, UK. As part of
the graduate scheme, he has had experience in several
departments within the company. While working in
trading, he had to keep a close eye on metal prices and
quickly react to any breaking news that could affect
them. It is a fast-paced job where the market can change
from minute to minute. In contrast he is now working
in market research, taking the long view and trying to
predict the future of hydrogen fuel cells.
www.rsc.org/TheMole
Did you
know?
© intelligent energy
After teaching in China for two years, Oliver returned to
the UK to look for a long-term job. ‘When I came back, I
knew it would probably take me a while to get a job – it
took about eight months in the end. I didn't want to just
waste that time, so I set up my own chemistry tutoring
business in the area where I live. I had experience of
tutoring and I also knew that there is a demand in the
UK for science teaching. I wandered around the local
area and put out flyers and ended up with a base of
students working towards A-level chemistry.’
‘The first project I worked on was looking at a
distributed hydrogen network – how you would actually
implement the infrastructure you need for hydrogenpowered fuel cell cars. I was looking at the needs of the
system, like distributing hydrogen and whether it should
be produced centrally and then shipped to different
stations, or should it be produced locally? What would
be more efficient and what are the opportunities for our
company in those areas?’
The future and beyond!
‘My second project I can’t talk so much about – I'm
investigating the technology behind fuel cells and how it
might develop in the future.
‘The hydrogen distribution network project looked
ahead until 2050 and the stuff I'm working on now
is looking ahead almost indefinitely at how fuel cell
technology will change and what the demand will be,
in terms of the materials required. It's quite strange
looking at a time frame that's almost longer than my
entire working career will be!’
After finishing his first year at Johnson Matthey in
the UK, Oliver will spend the next two years working
at their factories in Shanghai and Hong Kong. ‘The
business is expanding pretty rapidly now in Asia, so it'll
be interesting when I go over there to see how I can
help out.’ With China as one of the largest and fastestgrowing economies in the world, it's a good time to
continue his Chinese journey through chemistry.
Fuel cell powered taxis
were used at the London
2012 Olympic Games. Find
out more about hydrogen
fuel cells with this article
from Chemistry World:
http://rsc.li/p51miz
March 2013 | The Mole | 11
£50 of vouchers to be won
Chemical acrostic
Puzzles
Complete the grid (contributed by Simon Cotton) by answering the
eight clues to find the answer in the shaded box. This will spell out a
transition metal whose oxide is an important catalyst.
Wordsearch
1
2
Find the 31 words/expressions associated with thermoelectric materials
making hidden in this grid (contributed by Bert Neary). Words read in
any direction, but are always in a straight line. Some letters may be used
more than once. When you have found all the words, use the remaining
letters to make a 7-letter word.
3
4
5
6
C
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G
A
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L
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B
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2. Noble gas that makes up nearly 1% of the
atmosphere.
3. I’m in nylon but not in polythene.
7
8
1. Jewellery metal also associated with mirrors.
T
N
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4. A metal that will melt in your hand.
C
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5. Precious metal found in catalytic convertors, with
immense ability to absorb hydrogen.
U
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W O
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AUTOMOBILE
CONDUCTING POLYMER
COVALENT NETWORK
CLATHRATES
CRYSTALS
CRYSTAL STRUCTURE
CURRENT
EFFECTIVE
EMISSIONS
ENERGY
ENGINE
FUEL ENERGY
GAPS
GENERATE
HEAT
IMBALANCE
ION
JUNCTION
LEAD TELLURIDE
MATERIAL
MECHANICAL
MODE
NANOCOMPOSITES
POWER
SCARCE ELEMENTS
SEEBECK VOLTAGE
SEMICONDUCTORS
SKUTTERUDITES
TELLURIUM
VOLTAGE DIFFERENCE
WAVELENGTH
6. Most abundant halogen in the oceans.
7. Marie Curie discovered this radioactive element and
named it after her native land.
8. A metal named after the village in Scotland where
it was discovered. Its salts give a deep red colour to
fireworks.
Y
January wordsearch solution and winner
The winner was Susanna from Hereford. The 7-letter word was PROTEIN.
T
Submit your answers online at
http://svy.mk/TM213ans
by Monday 15 April.
A correct answer for each puzzle, chosen at
random, will win a £25 Amazon voucher.
B
I
T
T
T
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I
U
M
H
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B
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January acrostic
solution and
winner
The winner was
Lucy Berry from
Oxford