As Professor of Explosive Chemistry, at this time of year, Jackie Akhavan always finds herself asked how fireworks go bang. Here she shares part of the secret and gives us an insight into the world of explosives and how she came to be in this career.
I study the science of explosives which is fascinating. I didn’t set out with this career path in mind. I left school not knowing what I wanted to do. I found physics and maths beyond my ability but loved chemistry. I went on to study chemistry at the University of Southampton and was then encouraged to do a PhD in polymer chemistry. I worked as a postdoc and while I knew I wanted a career in academia, I was advised to work in industry first, which I did.
Managing to cause a container with explosives to blow up was not my proudest moment! I was working on an experiment with Semtex which led to the container exploding. Luckily there were no injuries. I was working on a powerful technique known as Raman Spectroscopy – basically the shining of laser light on materials and studying how the wavelength of light changes depending on the material’s properties. This technique was instrumental in helping distinguish between different types of plastic explosives and the tracing of the origins of Semtex used by the IRA.
Much of what I do is secretive and commercial-in-confidence, however, some of the science is still publishable even if the application isn’t.
At the moment TNT is used to bind an explosive composition together, but it has a low melting temperature and does not age very well. One way of replacing TNT is with a polymer which will bind the explosive crystals together. A polymer could be described as spaghetti if you were able to look at it with x-ray eyes.
I came across Cranfield when searching for jobs for a friend. I applied for a lectureship in polymer chemistry and the rest is history. It was perfect; I was teaching polymers and doing research in explosives. 
My first contract was with Standard Fireworks putting polymers into firework compositions.
Fireworks are fascinating and I always find myself asked how they work. In their packaging they are safe. I would never tell anyone how to make them or recommend it as it is dangerous as well as illegal. But I can disclose the ingredients. Gunpowder, which is made of carbon, provides the fuel and is what gives a firework its oomph, potassium nitrate provides the oxygen and then sulphur is used as an ignition and cementing agent. When you heat the sulphur it brings the carbon and oxygen together and after initiation, it produces the thrust. The addition of strontium results in a red flame, and barium a green flame. The colours are created through a blend of different compositions in the capsules within a firework.
Understanding how explosives will behave in any given environment is really important so risk can be minimised. Explosives have such wide-ranging uses. I have worked with the British Antarctic Survey who are using them during their surveys of ice thickness. The correct handling is vital as is knowing what impact extremely cold temperatures may have on them – do they become more or less sensitive? The safety of soldiers when transporting and handling explosives is another area my work expands into.
Environmental consideration has become more topical. The destroying of legacy items in an environmentally responsible manner is another aspect of my work. It comes full circle.
My work is contributing to the fight against terrorism. As one of the few universities with an explosives licence, we have manufactured improvised liquid explosives so we can develop detectors used at places like airports. Hopefully, soon you will be able to go through an airport with a bottle of water and not be stopped. We have looked at various methods of detection as part of a 
European Union programme; this includes synthesising polymers which change colour when in contact with liquid explosives or the vapours coming from them – known as colormetrics.
Sniffer bees were an interesting insect to work with. We were investigating whether a bee could be trained to detect explosives. While they could detect the additives in an explosive, when it came to using pure explosives with no additives, the experiment failed.
Testing the high test peroxide for the supersonic Bloodhound car was something I’ve worked on. This car will attempt to break the world land speed record, hitting speeds of 1,000mph. The people developing it are engineers, not chemists. As well as investigating what happens if the oxidiser spills on the car’s components, we are helping them with the safe handling of the oxidisers.
3-D printing is our latest area of research. My colleague Dr Ranko Vrcelj and his research team are developing a 3-D printer for the manufacture of explosives, which will be portable and capable of producing complex explosives components.
Want to find out more?
Read about the work of the Centre for Defence Chemistry and watch their latest video on our website.