News — Graphene research

Silicon Valley - the birthplace of tech superpowers Apple and Google, an innovation hub where the worlds elite software developers, accountants, designers and investors are localised, seeking out collaboration to create the next big App or device. It is this type of environment that James Baker, CEO of the £60m Graphene Engineering Innovation Centre (GEIC), is aiming to establish in Manchester for the next generation of graphene and advanced materials-based products.

Graphene is a 2D hexagonal array of carbon atoms that is the strongest and thinnest material known to man. It was first isolated at the University of Manchester in 2004 by Andre Geim and Konstantin Novoselov, who were awarded a noble prize for their work with the material six years later. Now in 2018, graphene has become one of the most researched substances in modern science. Graphene’s unique set of record breaking properties opens a landscape of potential applications spanning from biomedical, membrane technologies, polymer composites and in energy storage devices, to name a few.

To accelerate the development of these applications, the University of Manchester constructed a centre dedicated to graphene research, the National Graphene Institute. Already we’re seeing start-ups sprouting from this environment, such as the award winning Eksagon Ltd, who are focussing on utilising graphene in clean energy applications. The GEIC is the next step in the scale up of graphene and 2D materials, with pilot plant facilities for composites, inks, membranes and energy storage applications. Alongside this, events will be hosted that bring together north west based companies to engage with these new disruptive technologies and help establish supply chains within the area. ‘Graphene City’ has already attracted hundreds of academics to the city to work on advanced materials, but it is expected that the industrialisation of these materials will help create many more jobs for locals in the north west. It may be bold to claim that the rise of graphene has sparked the next industrial revolution in Manchester, however it is already clear that this science is making waves throughout the city and will continue to do so in years to come. If you would like to find out more about graphene, please do get in touch.

The Internet of Things, often referred to as IoT, refers to a network of physical devices which are able to communicate data. These devices can include cars, appliances, heating, lighting and security systems. In order to work, these devices need to be equipped with software, electronics and sensors, they also need to work with the internet infrastructure that already exists. Consumer IoT devices are already on the market in the shape of smart home appliances such as Hive Active Heating and The Amazon Echo, however the vision for the IoT stretches into the connectivity of trillions of devices - a vision that can only be realised through further innovation and research of all aspects required by the IoT.

A recent paper published in Scientific Reports demonstrates the potential for graphene oxide in wireless humidity sensing. The group investigated the relative dielectric permittivity of graphene oxide under various humidity conditions at GHz, showing that increased humidity leads to an increase in the permittivity. This is a result of higher humidity leading to a greater uptake of water. By printing a graphene antenna with the graphene oxide layer, the researchers were then able to create a battery free and wireless radio-frequency identification (RFID) humidity sensor. As the device is sensitive to its surrounding humidity, it could be used as a low-cost local humidity sensor in IoT applications.

This research serves as another great example of how graphene oxide has the potential to enable a diverse range of innovations and applications. The graphene oxide supplied through GOgraphene is being used in both academic and industrial research in many sectors. If you are interested in using graphene oxide in your research, please let us know and a member of the team will be happy to help you.

Scientific Reports, 2018, 8, 43

The “wonder material” graphene is a 2D hexagonal array of carbon atoms that possesses a number of remarkable and record-breaking properties. Since its first isolation in 2004, a vast amount of research has explored the fundamental physics and potential applications for the world’s first 2D material, and in doing so achieving global acclaim. Now in its teenage years, we are witnessing the maturing of graphene applications. There are graphene-composite products already publicly available, and many more disruptive technologies now becoming closer to commercialisation. This article summarises the pivotal graphene stories of 2017.

A Nature publication made global headlines in November for its use of “graphene balls” as a novel advanced anode for lithium ion batteries in mobile phones. The material consists of silica particles coated with a layer of graphene, enhancing the energy capacity by 45% and charging rate by 5 times, equating to a fully charged phone in just 12 minutes! This is just one of the hundreds of studies conducted that utilises graphene to improve the performance of batteries and supercapacitors for energy storage applications. Researchers at the University of Sussex proved that the battery is not the only component of mobile devices that graphene can enhance. Here, graphene and silver nanowires were coated onto acrylic plastic to produce a highly conductive, flexible screen. This is one of the contenders in the race to replace the brittle indium tin oxide screens used in our mobile phones today. It can be noted that this research is very fresh, which poses the question - can this technology be industrially scaled? And if so how many years will it be before flexible phones with a 12-minute charge are commercially available?

Not only is graphene highly conductive, it is also the strongest material known to man. This property was utilised by scientists at MIT to create a material that was 10 times stronger than steel, whilst possessing only 5% of its density. In this study, 2D graphene sheets were compressed and heated to form a 3D structure that could be used as a lightweight replacement for steel in construction and infrastructure. This breakthrough may even spark the imagination of those in the field of aerospace. The material’s extremely low density would enable easier transport into space, allowing for the interplanetary construction of space stations and colonies at a much lower cost.

The use of graphene oxide in water purification technology has also been a subject of much interest over the past year. Whilst it is common knowledge that graphene oxide has selective permeation to water, researchers at Hubei University have designed an alternative solar powered route to purify water. This technology uses a graphene oxide aerogel, which when exposed to sunlight can heat up water to 45 ^oC. This gives rise to a quicker evaporation process through the highly porous aerogel structure. This steam can then be condensed as pure water through a low energy method. It is unknown if this process is economically viable at an industrial scale, and further work to increase the heat conductivity may be required.

Although the majority of these stories describe the advancement of graphene technologies, 2017 was also the year that launched a number of exciting commercial products. Joining the likes of graphene enhanced bicycle tyres, skis and fishing rods was an ultralight, high-performance watch, the RM50-03. Produced by Richard Mille and McLaren F1 in collaboration with the University of Manchester, this product may open the door for the development of graphene applications in the automotive industry in years to come. One crucial area that needs to be considered for the commercialisation of all graphene technologies is the materials availability, and it’s here where the expertise of William Blythe comes into play. The GOgraphene team at William Blythe are committed to the development and scaling-up of our graphene products, and pride ourselves in our abilities to work with our customers to optimise their technologies. If you would like to learn more about how graphene can be utilised in your applications, please do get in touch.

Graphene oxide has gained nationwide acclaim in recent years as a result of advancements in water purification using graphene oxide membranes. However, the researchers at GOgraphene have learnt that this 2D material can be utilised in a variety of purification applications. The global adsorbent market is expected to reach $4.3 billion USD by 2020, and the purification of liquid systems such as petroleum and water constitutes a large segment of this. The prevalent use of dyes, pesticides and polymers in many societies has led to the contamination of water. An understanding of the harmful effects of these molecules has lead to stricter regulations on the limits of contaminants in our drinking water. This has fuelled research into adsorbent materials suited for the removal of harmful molecules, and among these materials is graphene oxide.

Graphene has a theoretical surface area of 2630 m²/g, which provides a massive area for the adsorption of molecules onto individual sheets. The delocalised aromatic system of graphene produces strong attractive forces between the aromatic components of organic dye molecules, as demonstrated in literature with methylene blue. A reduced graphene oxide adsorbent was also demonstrated to have an adsorption capacity of 1200 mg/g for pesticides, being larger than any material investigated for this purpose. Alternatively, graphene oxide was combined with magnetic iron compounds for the adsorption of toxic arsenic ions, allowing for easy recovery of the adsorbent material and contaminants via magnetisation.

The versatility of graphene materials is consistently exemplified in research from around the globe, and applications like this indicate how they will make a positive impact to our lives in years to come. If you have any enquiries about the applications of graphene oxide, or about how it can improve your existing application, please do get in touch.

Environmental Science and Pollution Research, 2016, 23, 9759-9773

Small, 2012, 9, 273-283

Colloids and Surfaces B: Biointerfaces, 90, 197-203

Graphene oxide is part of the graphene family – two dimensional materials based on a honeycomb framework of carbon atoms. While graphene is pure carbon, graphene oxide has a series of oxygen functionalities decorating the surface of the honeycomb carbon structure. The oxygen functional groups can be complex, often containing alcohol, acid and epoxy units.

The presence of oxygen groups leads to significantly different properties when comparing graphene and graphene oxide. For example, graphene oxide can disperse easily in water, while graphene will not disperse. This is because the oxygen groups make graphene oxide a hydrophilic material, allowing water molecules to intercalate between the layers, separating them and forming a stable dispersion. As graphene is a hydrophobic material, this does not occur when trying to disperse graphene in water.

Another interesting difference between graphene and graphene oxide are their conductive properties, in terms of both thermal and electrical conductivity. While graphene has exceptionally high conductivity, graphene oxide is considered an insulator. Both materials have the same carbon framework, and as such the difference in functionality is directly related to the presence of the oxygen groups. The lower the oxygen content in graphene oxide, the higher the conductivity of the material.

There are some instances where the dispersion characteristics of graphene oxide are needed, but the properties of graphene are more relevant. In these instances, it is sometimes possible to convert graphene oxide into a material more similar to graphene in situ. This is done by reducing the graphene oxide, either chemically or thermally, to leave reduced graphene oxide. Reduced graphene oxide has a significantly lower oxygen content than graphene oxide, resulting in properties much closer to those of graphene. Reduced graphene oxide is distinguished from graphene because it will not have a pristine surface – the removal of oxygen groups usually leaves some defects on the surface, including some remaining oxygen functionality. For many applications, the surface of reduced graphene oxide is appropriate for yielding the desired functionality, in other instances the defects can lead to new, different properties for the material which make it interesting in its own right.

For more information on graphene oxide and how it could be of use for your research, please get in touch and a member of our team will be happy to discuss your work.