2019 has been declared by UNESCO as the Year of the Periodic Table. To celebrate, we are releasing a series of blogs about our favourite elements and their importance to the chemical industry. Today’s blog is about one of the most abundant and most used elements, carbon!
Carbon could be called the element of life – it can be found in every living creature on Earth in a variety of different forms, from the backbone of your DNA, to the taste receptors in your tongue and the hormones controlling your hunger. Carbon-based chemistry surrounds us – in the air we breathe, in the food we eat and in the soil beneath our feet.
So, why is carbon so important to life? Carbon’s chemistry allows it to form large, intricate 3D structures, which are the basis of its interaction in biology – like jigsaw pieces that come together to build a tree, an elephant or a human being.
The study of carbon-based chemistry, or organic chemistry, has allowed us to better understand our living world and the interactions that occur, leading to development of better tasting food, higher yielding crops and more efficient medicines to improve our health.
In the early 19th century, chemist Justus von Liebig began synthesising organic, carbon-based molecules and said: ‘The production of all organic substances no longer belongs just to living organisms.’
Since then, hundreds of organic compounds for medicinal use have been synthesised – from adrenaline to ibuprofen – and hundreds of unique synthesis pathways have been described.
Organic chemistry – the study of carbon-based chemistry – has given us hundreds of modern medicines.
Carbon in materials
Atoms of carbon can make four bonds, each with another carbon attached, to arrange themselves into different molecular structures and form completely different substances. These molecular structures, known as allotropes, can result in vast differences in the end-result material.
For example, one allotrope, diamond, is the hardest and highest thermally conductive of any natural material, whereas another, graphite, is soft enough to be used in pencils, and is highly conductive of electricity.
Graphene is carbon allotrope that exists in thin, 2-dimensional layers, with the carbon atoms arranged in a honeycomb formation. Scientists had theorised its existence for years, but it was not isolated and characterised until 2004 by Andre Geim and Konstantin Novoselov at the University of Manchester, UK. The pair won the 2010 Nobel Prize in Physics for their work.
The structure of carbon atoms in graphene.
Graphene is a highly conductive, flexible and transparent – this means it can be used in electronics, medical biotechnology, and a variety of other innovative solutions.
Another innovative material made from carbon is carbon fibre, which can then produce carbon-fibre reinforced polymer (CFRP). CFRP is a polymer interwoven with fibres of carbon, which is 5-10μm in diameter. The mixture of these two materials gives an extremely strong but lightweight material, useful in building products from aerospace and automotive, to sports equipment and technology.
Fueling the world
The name carbon comes from the Latin carbo meaning coal, and until recently most of our energy was generated by the consumption of carbon through the burning of naturally occurring carbon-based fuels, or fossil fuels. When these fuels, such as coal, natural gas and oil, are burnt, the combustion reaction generates carbon dioxide (CO2).
CO2, produced by burning fossil fuels, is thought to be a contributor to climate change. Image: Pixabay
High production of the by-product CO2, and its release into the atmosphere, is considered to have a negative environmental impact and is thought to contribute to global warming and climate change. Fossil fuels are not a renewable resource and supplies are expected to diminish in the next 50-100 years.
Consequently, there has been a movement towards more renewable energy, from wind, solar and hydropower, driving a move towards a low-carbon economy. These energy sources are generally considered to be better for the environment, with lower amounts of CO2 being produced.
Chemical engineer Jennifer Wilcox previews some amazing technology to scrub carbon from the air, using chemical reactions that capture and reuse CO2. Video: TED
In this strive for a low-carbon economy, new technology is being used that prevents the release of CO2 into the atmosphere in the first place. Carbon capture and storage (CCS) takes waste CO2 from large-scale industrial processes and transports it to a storage facility. This CCS technology is one of the only proven, effective methods of decarbonisation currently available.