Dr Rachel McLaren has recently completed her PhD in chemistry, carrying out research into the modification and application of graphene-based materials. Graphene describes a single layer of graphite, the material which is present within pencils and often incorrectly referred to as ‘lead’. Graphene-based materials can be utilised in many applications, including to assist in oil-spill clean-ups.
I am 26 years old and originally from Worthing, West Sussex. I initially undertook my BSc in Chemistry at The University of Reading, before moving to South Wales to pursue my PhD at University of South Wales (USW).
My PhD project has been funded by the Knowledge Economy Skills Scholarships (KESS2), which operates in collaboration with an industry partner - in my case South Wales-based Perpetuus Carbon Technologies Ltd - and a Welsh University. KESS2 is supported by European Social Funds (ESF) through the Welsh Government.
Graphene describes a single layer of graphite, comprising a honeycomb array of carbon atoms and was first isolated in 2004 at University of Manchester. These carbon atoms are held very tightly to one another, granting graphene its exceptional strength and mechanical properties. Graphite typically consists of many thousands of graphene layers; however, these can be isolated into fewer layered stacks and single layers of graphene by simply peeling the layers with scotch tape, or using other innovative industrial methods.
Layered stacks and single layers of graphene possess a number of interesting properties. They are often used to enhance the strength of materials such as tennis racquets and bike frames. In addition, they also possess interesting thermal and electronic properties and show promise for gas storage applications.
Unfortunately, however, the commercial capabilities of this wonder material are still not well matured, and graphene-based materials still have a little while to go before we begin to see them in our everyday products. This is due to issues with its synthesis, electronic structure and poor dispersibility in liquid media. This slow progress, however, is not uncommon for new materials. The time it takes for the discovery of a new material until its implementation into market is typically somewhere between 20 to 30 years, as shown by other technologies such as Kevlar.
There are a number of challenges with graphene and its stacked forms. Firstly, they are difficult to synthesise on a large scale, with high purity. The initial synthesis process involved peeling of layers from graphite, however, this forms graphene on a minute scale. Secondly, these materials are often difficult to process. The carbon structure is very inert, therefore it can be difficult to chemically bind other components to the lattice. Thirdly, graphene and its stacked forms are inherently difficult to form dispersions with. As such, many applications which require the materials in liquid media are hindered.
In light of these challenges, it is essential to explore new routes to synthesise and modify graphene-based materials to enhance their growth into market.
My research involves carrying out synthetic modifications on the graphene-based materials to manipulate their properties and therefore expand their application.
Oil spills are an issue all over the globe, and incidences where large amounts of oil are spilt into oceans can result in serious effects to the environment and aquatic life. Current technologies such as booms and dispersants find use in removing and containing this oil, however, they do not come without their drawbacks.
This synthetic modification of graphene-based materials with polymers allows for unique properties to be introduced. This addition of polymers onto graphene-based materials describes a process known as “functionalisation”.
Through functionalisation with specific polymers, oil-repelling, water-attracting behaviour can be introduced to the graphene-based material, to provide it with application within oil spill clean-up. These materials can then be utilised as membranes for oil/water separation.
In the context of oil-spills, these membranes can be applied as “nets” to scoop up oil from the surface of water. The water is allowed to passively run through the membrane, whilst it simultaneously repels the oil, retaining it on the surface. The oil can be then easily be poured off.