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Message from the editors Welcome to the second edition of The Atom, Godolphin’s chemistry magazine. This magazine was created by a group of the LVI with the aim of collating articles from a variety of areas within chemistry, which we hope you will find fascinating and informative. In this issue we have articles ranging from sustainable fashion to slime and an inspirational woman in STEM. You will also be able to get some great book reviews from our very own chemistry department, which is great for wider reading if you want to study chemistry later, or are just enthusiastic like us! We hope you enjoy reading the articles! Tabitha and Rojin
Editors
Tabitha Iliffe Rojin Zahaki
Writers
Nadia Baghai Jacqueline Byun Roxanna Fahid Clara Gilardi Jess Gilbert Hannah Goldin Freya Gubbay Tabitha Iliffe Angelina Kim Aya Kodmani Ella McKean Atti Mowat Lara Weeks Rojin Zahaki
Cover by
Jess Gilbert
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Contents Chemistry in the world around us Flour, sugar and eggs: the chemistry behind these key baking ingredients The chemistry behind slime (+ recipe) Why do glow sticks glow?
Sustainability spotlight Can sustainable fashion start from food waste? Should we be reconsidering our lockdown athleisure wear?
Women in STEM Marie Maynard Daly
Chemistry challenge! Quiz, riddles, codebreaker Science fiction reading recommendations
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Flour, sugar and eggs: the chemistry behind these key baking ingredients Some may believe that the talent and skill of a baker does not come hand in hand with a great chemist, however, that is far from the truth. Chemistry is fundamental in order to achieve great culinary success, appearing throughout the whole baking process, right
curly chains that form strong hydrogen bonds with one another. By kneading, mixing and resting the dough, it encourages these bonds to form, therefore allowing it to develop its elastic properties that we require. However because glutenin is so great at giving the
from start to finish. When one takes a bite from a light fluffy luxury chocolate cupcake, with almost complete certainty, chemistry will be the last thing on their mind. However, without the science behind it, the recipe would simply fail, as baking is not too far from a scientific experiment. But, how does chemistry play a part? This article is going to touch upon the chemistry behind some of the common ingredients and the role that they play.
dough
Firstly, let's take a look at the ingredient which
back to its original form, which is why we
is arguably the base for all baking - FLOUR.
then depend on the gliadin. Unlike the
Flour is the powdery substance produced
glutenin molecules the gliadin molecules
from grinding any type of raw grains, roots,
don’t change shape in the presence of water,
beans, nuts, or seeds, yet in baking, the most
they remain in their compact shape which
commonly used is from cereal grain. Now, in
allows parts of glutenin chains to slide past
order to understand how flour reacts in
each other without bonding, meaning the
baking, it's important to understand its
dough can be shaped.
composition. There are two major protein components present in flour, known as Gliadin and Glutenin. When this pair of proteins react through a hydration reaction, due to the presence of water in the milk and egg, they combine to form a larger protein known as gluten. When the water is added, glutenin molecules team up to form long,
elasticity
it
makes
it
almost
impossible to shape it, as it keeps bouncing
When we think of baking, our minds instantly associate it with sweet, sugary, indulgent delights that we can treat ourselves to. And the obvious component that lends to this idea is SUGAR. However sugar does much more than just
4 sweeten a cake. It's responsible for the moisture of cake, carmalisation, and is a key component in a series of reactions known as the Maillard reactions.
For example; Maltol, which is produced during the first stages of caramelization, is mainly responsible for a caramel toasty-like flavour.
In order to break this down, let's start with moisture and the way it interacts with sugar. Sugar is hygroscopic, meaning it has a tendency to attract and hold onto water molecules. So, by keeping water locked up in place, it disrupts the network structures created by the flour, and in doing so prevents
Unlike caramelisation, which only requires a
the cake from being too rigid or dense!
simple sugar, the Maillard reaction occurs
Both caramelisation and Maillard reactions can be classified under the same overarching category, browning reactions. Caramelization is a type of non-enzymatic browning reaction that relies on the high heat to oxidise a simple sugar. We can use sucrose (a type of disaccharide) in order to explore the process
due to the interactions between an amino acid and a reducing sugar, under the addition of heat. The reactive carbonyl group of the sugar (either a saturated sugar aldehyde or saturated sugar ketone) interacts with the nucleophilic amine group of the amino acid, forming odor and flavor molecules (either a unsaturated sugar aldehyde or unsaturated sugar ketone). A large variation of flavour can be produced, as different amino acids produce different amounts of browning, therefore different products are produced. Despite there being a growing market for vegan substitutes in baking, such as flax
in further detail. Firstly, thermal decomposition of sucrose begins by the formation of fragments of glucose
and
fructose
(both
eggs and applesauce, there are some properties of a chicken EGG that just cannot be replicated in baking.
monosaccharides). Further heating causes
Eggs are multifunctional in the role that they
these
the
play in baking. Firstly, a whole egg (yolk and
molecules,
white) has a water content of 74%, meaning
allowing the mononsachharies to react with
that in the hot conditions of an oven, an
each other and form bonds between each
evaporation reaction occurs as the water
other, in multiple different combinations,
changes state from its liquid form to its
creating a range of different caramel tones.
gaseous state, steam. The steam produced
monosaccharides
previously
attracted
to
water
release
5 helps the process called leavening to concur,
network of lectin surrounding the air bubbles,
which is the expansion and rising of
holding them in place. Whilst this is a crucial
dough/batter. If we take a look more
process of the protein component in eggs, it's
specifically at just egg whites, they account
not the only useful trait that they possess.
for 2/3 the total volume of the egg and are
The protein in the egg also provides the
made up of mostly water and some proteins
diverse variety of amino acids that are
known as lectins.
required for the Maillard reactions mentioned in the section on sugar. Now you have read a bit more about the vitality of chemistry in baking you can apply your knowledge in your next batch of cookies. Happy baking! By Freya Gubbay References and further reading:
Lectins are long chains of amino acids that fold into spherical tangles, however when air bubbles are incorporated into the lectins,
https://nzic.org.nz/app/uploads/2017/10/6D. pdf
during the whipping or beating process, the
https://sciencing.com/chemical-reactions-inv
lectin unwinds and stretches to form a long
olved-baking-cake-7173041.html
elastic web. In order to understand why the addition of air causes this change in structure and bonding, you must know that some
https://bakerpedia.com/processes/carameliz ation/
amino acids in lectins are hydrophobic (water
https://www.ifst.org/lovefoodlovescience/res
fearing) whereas others are hydrophilic
ources/carbohydrates-caramelisation
(water
loving).
In
the
initial
compact
formation of lectins, the hydrophobic amino
https://www.scienceofcooking.com/carameli
acids are in the centre of the sphere and from
zation.htm
the water and the hydrophilic amino acids are
https://www.scienceofcooking.com/maillard_
on the outside in contact with the water. As
reaction.htm
the air is slowly incorporated into the egg white, the hydrophilic part of the lectin is now
https://www.eggs.ca/eggs101/view/95/food-
in contact with the air, not the water, so the
science
lectin unfolds in order to submerge the
https://www.exploratorium.edu/cooking/egg
hydrophilic amino acids in water, forcing the hydrophobic amino acids to stick to the air. New bonds are formed which creates a
s/eggscience.html
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The Chemistry Behind Slime! The main reason for slime’s unique texture is Who else remembers when asmr and slime
due to polymers. A polymer is essentially a
first became a craze about 5 years ago? I
long chain of repeated molecules linked
certainly do. Making slime fascinated people
together. In this case, the glue that we use to
worldwide- not to mention the extremely
make slime is the polymer, which is made up
satisfying videos all over the internet- but
of repeating units of a molecule called
what about the basic slime science behind
polyvinyl acetate to create an extended
this stretchy, sticky substance? And why were
sequence. Within the glue, these chains are
we all using contact lens solution in a great
able to slide past one another very easily and
effort to make our own? Hopefully by the end
this allows PVA glue to flow as a liquid.
of this you can understand the never ending magical properties of slime from a chemistry perspective, and maybe have a stab at making it yourself!
Now that we have discussed the glue aspect of slime-making, it is time to move on to the activator. Whether you use borax, liquid starch, laundry detergent, or contact lens
A large part of chemistry is the different
solution,
the
same
principal
chemical
states of matter- solids, liquids and gases-
reaction occurs to make slime. These
and how these act under different conditions.
activators contain boric acid and sodium
If someone asked me what state slime is in, I
borate, and when they are dissolved in water
would probably say that it is solid. But how
they form a substance called a borate ion. An
could this be if slime takes the shape of any
ion is an atom or molecule that has a charge.
container it is in? In fact, slime is a
When this solution is added to the glue
non-Newtonian fluid. This means it is neither
mixture, the borate ions help connect the long
solid nor liquid. Slime can be held like a solid
polymer chains in the glue together in a
(we can’t hold water in our hands!), yet it
process called cross-linking. This prevents
oozes out like a liquid. Newtonian fluids, like
the glue from moving and flowing as easily
water, can only change state when there is a
and the mixture begins to become slightly
change in temperature (think about freezing
more solid-like- AKA it becomes more
water to make ice!) Rather, non-newtonian
viscous! When enough polymer chains in the
fluids become more liquid or solid when we
glue become correctly linked to each other,
apply a force. You may have noticed that
the glue solution eventually starts to take
slime becomes more solid-like when you
shape, changing from being very liquidy to
squeeze it. We can also say that slime has an
much more rubbery and transforming into
increased viscosity.
slime. This gives slime it’s thickness and stretchiness! You can see the borate ions interacting with the glue mixture here, the
7 molecules in the slime have essentially become tangled.
Another cool fact about this mechanism is that it is endothermic. This means that when the polyvinyl acetate in glue combines with the borate ions from the activator, the reaction actually absorbs heat energy from the surrounding environment, which is why slime will feel cold to the touch! It is certainly clear that chemistry really is all around us. Unicorn slime, galaxy slime, butter slime and even colour changing putty all stem from science. Chemistry is great for not only
aiding
revolutionary
technological
advancements, but also creating stuff that is fun to play with (and very stress relieving!) Perhaps in the future we will discover a new use for slime that will transform the course of The chemical bonds between the borate ions and the glue polymer break and reform very easily. They are strong enough to hold the
our lives. But for now, you can’t go wrong with a bucket of goo! By Tabitha Iliffe
slime together, but still weak enough to allow the slime to be easily bent into all sorts of other shapes. As a non-Newtonian fluid, slime becomes harder when squeezed. This is as a result of the cross-linking process of the polymers. When the slime is left untouched, the particles curl up and these coils will easily slip
over one another. However, when
pressure is applied by pressing or stirring the slime, some of the coils unwind and become twisted, rendering the slime flow more difficult. When you try to pull it apart quickly, slime rips because of this.
The ultimate slime recipe! Ingredients: 1. 230ml PVA glue 2. 115ml water 3. 1 tsp bicarbonate of soda 4. 1 tbsp contact lens solution (this must contain boric acid and sodium borate) 5. Food colouring (this is optional) Method: 1. Pour the PVA glue and water into a bowl and mix until fully incorporated. You can also add any food colouring, sequins,
glitter
or
embellishments here.
any
other
8 2. Add the bicarbonate of soda to the mixture, stirring thoroughly. At this point, the slime mixture should still be slightly runny.
https://littlebinsforlittlehands.com/basic-slim e-science-homemade-slime-for-kids/ https://blog.giftedstudy.org/the-science-behi
3. Slowly add the contact lens solution
nd-slime/#:~:text=The%20science%20behind
and stir. You should feel the mixture
%20slime%E2%80%93it's%20chemistry!&text
thicken up quite quickly and when it
=Silk%2C%20wool%2C%20and%20DNA%20ar
starts coming away from the sides it’s
e,past%20each%20other%20somewhat%20e
time to get your hands in and knead
asily.
the mixture. If your slime is still too sticky add a few more drops of saline solution until it firms up - be careful with this as adding too much will make the slime hard and brittle! References and Further reading: https://www.acs.org/content/acs/en/educati on/whatischemistry/adventures-in-chemistry /experiments/slime.html
Slime recipehttps://www.curiscope.com/blogs/blog/the-p erfect-slime-recipe
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Why do glow sticks glow?
peroxide and prolongs the shelf life of a glow stick. In the outer layer, diphenyl
Glow sticks were originally a military tool and
oxalate, which is also known as cyalume,
had a lot of different uses: experimental
is found. This is the chemical that reacts
bombs, creating targets for air strikes and as a
with hydrogen peroxide to enable the glow
replacement
flare.
stick to glow. Furthermore in the outer
Furthermore, in a catastrophe where electricity
layer, butyl benzoate, a super solvent,
is out glow sticks are one of the only sources
keeps the colours and oxalate esters
of light considered to be safe to use still, as
(diphenyl oxalate)
they are a man made light source and don’t
them spread through the outer tube.
give off heat. On top of this, as they are
super solvent is a substance which
waterproof they can be used by scuba divers
another substance can be dissolved in.
to help see the bottom of the ocean. Overall
Commonly, butyl benzoate is used to
glow sticks have many more uses than just for
preserve cosmetic products. Finally in the
bracelets and party decorations. So what
outer layer the fluorescent dyes are found,
actually happens when you snap a glow stick?
which are the determiners of what colour
to
the
traditional
flowing and keeps A
the glow stick will glow. Most of the dyes Glow sticks glow due to a chemical
have a base structure of three fused
reaction which occurs when the thin glass
benzene rings. A benzene ring is a ring of
inner tube within the outer plastic tube is
six carbon atoms which are unsaturated,
broken by you snapping it. Within the inner
meaning the molecule contains double
sealed capsule that breaks open you find
bonds. The colour is determined by what
hydrogen peroxide (H2O2), a chemical
compounds are attached to the rings.
commonly
found
disinfectants,
in
along
bleaches with
and
dimethyl
This irreversible reaction typically glows
phthalate which makes up 90% of the
for
inner
snapped,
depending on the dyes used. The reaction
hydrogen peroxide triggers the chemical
occurs between hydrogen peroxide and
reaction that enables the glow stick to
diphenyl oxalate (made up of a double
glow. Dimethyl phthalate is a compound
ester and an oxalic acid), to form 1,2-
that dilutes and preserves the hydrogen
dioxethanedione (C2O4) and two phenols.
capsule.
Once
it
is
around 12 hours, but can vary
10 This compound, C2O4, is highly unstable
create
and very reactive. When this molecule
diphenylanthracene to create a blue glow.
reacts with the dyes, carbon dioxide is
When you combine these two molecules,
released and the dye becomes excited.
you create a purple and by altering the
Therefore, the dyes emit energy as a
ratios and including more of one you can
photon (light energy) creating the glowing
create a pink or more of an indigo colour.
effect to make the dye stable again. This is
For a yellow you can use Rubrene and for
called chemiluminescence, which is a
green,
reaction that releases light. The only thing
bis(phenylethynyl)anthracene. Once the
that
reaction
affects
chemiluminescence
is
a
reddy
glow
and
9,10-
9,10-
inside
the
glow
stick
has
temperature. Higher temperatures cause a
occurred, it cannot be turned off. However
brighter glow, but it’s for a shorter period of
it can be slowed through placing the glow
time. Some manufacturers use catalysts
stick in colder temperatures, but it will only
like
stop reacting when the full reaction is
sodium
salicylate,
an
alkaline
compound to speed up and intensity the
complete.
glow. In terms of the colour of the glow stick, manufacturers use Rhodamine B to
By Atti Mowat
11
Can sustainable fashion start from food waste? Sustainable fashion and some alternatives that have recently been developed in the chemistry research field. With the rise of global
warming
and
threat
to
the
environment, the need to develop or change the sources and exports of human
What
are
some
examples
of
unsustainable fabrics?
fashion is greatly increased. Sustainability
Polyester - this is not biodegradable [takes
in general is seen as an essential part of
an extremely long time to be broken down
the change needed to decrease human
naturally by the environment] and when it
effect on the environment.
is being produced it is partially derived from oil. The oil and gas industry is a
So what actually is sustainable fashion?
major contributor to greenhouse gases
Sustainability itself is being able to
that are causing the global temperature to
maintain and meet the needs of the
rise significantly each year.
present without compromising the ability of future generations to meet their needs.
Cotton - it can take more than 20,000 litres of water to produce one cotton t-shirt and
In terms of fashion, being sustainable
a pair of jeans. The excess water ends up
would focus on sustainable sources of
polluting
material, shipping methods, packaging
produced when making cotton clothes.
and other social and ecological aspects.
rivers
with
the
chemicals
Leather - although it is a byproduct from
For materials to be sustainable they need
another industry, the carbon footprint of
to tick a certain number of boxes. Namely
this industry is extremely large. The
they
tanning process of leather uses chrome.
must
biodegradable
be
organic,
fabrics,
use
natural, parts
of
This produces a lot of toxic waste and
recycled clothing, repurposed materials
serious
and use Non-toxic dyes.
workers.
harm
to
industrial
tannery
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What is vegan leather? Vegan leather is a material that mimics the look and feel of animal leather.
Grape leather
Historically, vegan leather was produced
This is a 100% recyclable bio-based
using unsustainable and non-eco friendly
polymer called grape leather. This is made
PU (polyurethane). This is a type of plastic
using grape waste from the wine industry.
which is incredibly damaging to the
This was created by a company called
environment because of how long it takes
VEGEA that received the top prize of the
to biodegrade. Just because this leather is
global change award.
vegan doesn’t make it environmentally friendly. In more recent developments, bio-based polymers are being created What are bio-based polymers? These polymers are materials made with a part organic component. Although bio-based products are not always biodegradable or compostable, the carbon footprint produced when using these materials would be much less than other polymers that are not bio-based. Many of these products are created from food waste. Apple leather The core and skin of the apples you ate could be made into a flexible leathery sheet called apple leather. The apple leather used is made using 50% apple waste (that has been powderised) mixed with 50% Polyurethane
Pineapple leather Another example is pineapple leather. It is just as the name says, it is created by taking the long fibres from pineapple leaves. Although it is not biodegradable, it is partially made using a waste product. This means no extra land, water and other resources are used when growing the leaves. There is also none of the toxic chemicals production.
used
in
animal
leather
13 These bio-based polymers are a step forward into sustainable fashion. This can only be achieved by further research into the chemical makeup of more plants and crops that have less impact on the environment.
This
research
is
still
continuing to produce more sustainable
How does this work?
and eco friendly fashion alternatives to
After pineapple harvest, the plant leaves
help develop the sustainable fashion
are collected and the long fibres are
industry even further. Next time you go
extracted using semi-automatic machines.
shopping why don’t you have a look at
The fibres are washed and dried. The dry fibres go through a purification process to remove any impurities which results in a fluff-like material.The key to creating the pineapple leather is the use of corn based
whether
your
favorite
stores source
sustainable materials? By Angelina Kim References and further reading: https://www.eco-stylist.com/a-guide-to-th
polylactic acid (PLA).
e-most-and-least-sustainable-fabrics/
Polyurethane vs polylactic acid? Polyurethane is a ‘thermoset plastic’. This means that it hardens as it is heated,
https://compareethics.com/sustainable-fa shion-101/
making it hard to recycle. Polyurethane
https://www.sustainyourstyle.org/en/sust
also emits toxic fumes if burned. Specific
ainable-leather#:~:text=Leather%20will%2
agents
0never%20be%20an,need%20additional%2
in
polyurethane
produce
greenhouse gases like carbon dioxide. Polyurethane definitely causes a negative impact on the environment.
0land%20and%20resources. https://www.tortoiseandladygrey.com/201 6/05/02/environmental-impacts-leather-fa
plastic
shion/#:~:text=Around%2080%25%20of%
substitute made from fermented plant
20leather%20worldwide,harm%20to%20in
starch (usually corn). It is biodegradable
dustrial%20tannery%20workers.&text=It%
and
20is%20true%20that%20making,will%20n
Polylactic
can
acid
be
(PLA)
referred
is
a
to
as
a
‘thermoplastic’. This means that PLA can liquify instead of burning, so it can return to its original state without much damage. This would mean easier recycling!
ot%20go%20to%20waste https://www.watsonwolfe.com/2018/09/2 2/what-is-vegan-leather/ https://www.ananas-anam.com/about-us/
14 https://www.hunker.com/13414626/the-di sadvantages-of-polyurethane https://olivercompanylondon.com/pages/ apple-leather#:~:text=Apple%20leather%2 0is%20a%20bio,fruit%20juice%20and%20c ompote%20industry.&text=The%20apple%
20leather%20used%20in,onto%20a%20cot ton%2Fpolyester%20canvas. https://www.creativemechanisms.com/bl og/learn-about-polylactic-acid-pla-prototyp e
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Chemistry Quiz! Is your knowledge as light as helium or as heavy as plutonium? 1. What are the most common 3 elements in the human body? 2. Who was awarded the 2020 Nobel prize in Chemistry? 3. What is the only letter not appearing on the periodic table? 4. Which metal has the highest melting point? 5. Ernest Rutherford was born in which country? 6. What is the centre of an atom called? 7. How much salt (NaCl) is in the average adult human body? 8. Water-based liquids can be described as acidic, neutral, or basic, with respect to pH. Which of these describes milk? 9. A drop of food coloring spreading out in a cup of water is an example of which transport process? 10. Which chemical causes the burning taste sensation when eating chillies?
Riddle H2O is water and H2O2 is hydrogen peroxide. What is H2O4? What did the bartender say when oxygen, hydrogen, sulfur, sodium, and phosphorus walked into a bar? Why does hamburger yield lower energy than steak?
Crack the code using the periodic table to uncover the secret message!
Answers: 1. Oxygen, Carbon, Hydrogen 2. Jennifer Doudna, Emmanuelle Charpentier 3. J 4. Tungsten 5. New Zealand 6. Nucleus 7. 250g 8. Slightly acidic 9. Diffusion 10. Caspaicin
Riddle 1. Drinking 2. OH SNaP 3. Because it’s in the ground state
Codebreaker: Transition metals are shiny and hard
16
Science Fiction Reading Recommendations! This Dark Endeavour By Kenneth Oppel Half Brother By Kenneth Oppel Lost on Mars By Paul Magrs Satellite By Nick Lake This Cruel Design By Emily Suvada It’s The End Of The World As We Know It By Saci Lloyd