News — GOgraphene

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

Polyoxometalates, or POMs, is the name given to polynuclear materials which contain transition metals and oxygen. They have been researched for a diverse range of applications, including photochemistry and energy storage. The most popular research area to date for POMs has been catalysis, where their redox properties and strong Brønsted acidity are utilised. The biggest problems with POMs include difficulty of separation and the poor availability of active sites. Support materials for POMs have therefore been of great interest within the scientific community as they may offer a simultaneous solution to both problems.

Many support materials have been researched for this purpose, with silica and polymers common choices. Graphene oxide is also of interest in this research area due to its high surface area and its ease of dispersion in a number of solvents. Accordingly, a recent paper published in Materials Chemistry and Physics focused on supporting polyoxometalates on graphene oxide and reduced graphene oxide for catalyst applications. The researchers discovered that there were three important parameters to control the adsorption; the presence of oxygen functional groups, the pH and the solvent were all key to achieving the highest possible adsorption capacity.

The research compared the ability of graphene oxide and two reduced graphene oxides, which had different oxygen contents. The highest adsorption capacity achieved by the research was 427 mg/g, which was achieved by graphene oxide. This indicates that a higher oxygen content is preferable when aiming for high adsorption capacities.
This paper is another example of the breadth of research which graphene oxide is currently being used in. If you have any questions about how your research could benefit from graphene oxide, please get in touch.

Mater. Chem. Phys., 2017, 299, 424

Graphene oxide was first reported in the literature over 150 years ago, at a time when there was little interest in exploring the benefits of the material in the multitude of application areas it is currently being used in. Interest in graphene oxide rose dramatically with the discovery of, and Nobel prize for, graphene. The subsequent years have seen the use of graphene oxide in a diverse range of applications, with many researchers focussing on graphene oxide as a potential precursor material for graphene with specific graphene oxide applications now under development.

With no suppliers, initial graphene oxide researchers were unable to purchase graphene oxide and therefore synthesised all of their own material. Despite multiple graphene oxide suppliers launching a variety of products for this market in the past few years, some researchers are still undecided as to whether they should purchase or make their own graphene oxide for their work. While William Blythe understand that there are always reasons to synthesise your own graphene oxide, we have tried to overcome some of the most common concerns around purchase with our GOgraphene webshop.

Consistent quality 

William Blythe are aware that some suppliers do not offer a consistent product. As an established chemicals manufacturer with over 150 years’ experience supplying chemicals, we ensure our graphene oxide meets the same high standards as our other products before we dispatch your order.

Flexibility

Buying from someone else will always reduce some of the flexibility compared to in house synthesis. William Blythe have tried to overcome this by offering multiple product forms, developing a high concentration dispersion which can be easily diluted and by taking requests for custom functionalisation of our standard material.

Availability 

To keep results comparable, most researchers do not want to swap materials supply part way through their research programme. We monitor our stock levels carefully to make sure we always have enough of our graphene oxide to fulfil our orders. Keep an eye on our lead times if you have any concerns

Volume 

Graphene oxide is currently only available for purchase online in relatively low quantities. Some researchers are concerned that the raw materials availability will prevent their application from being scalable. As William Blythe has already developed scale-up plans, this need not be a concern. Not only is our process is scalable, but within 12 months of demand projections requiring it, William Blythe can scale on to a dedicated multi-tonne production facility.

Price 

Some materials suppliers fluctuate their prices, meaning there are some researchers who do not want to become reliant on a materials supplier. The graphene oxide available on the GOgraphene webshop has never been increased in price. Depending on the currency you are purchasing in, the screen may display slight variations, however our GBP pricing has not been increased since launch.

We hope that the above helps to alleviate some of the concerns which we know exist in the marketplace. If you have other concerns or questions regarding purchase versus in house synthesis, please get in touch. There are a host of benefits to purchasing graphene oxide, including saving time and removing the need for hazardous synthesis. If you are ready to switch to buying graphene oxide, please take a look at our current product portfolio.

Raman spectroscopy has been used to prove William Blythe's graphene oxide readily disperses into monolayers.

Raman spectroscopy is a well-known and very common technique for the analysis of graphene related materials. By assessing the position, intensity and ratios of the D and G peaks, it is possible to learn a lot about the material in question. Useful information from raman spectroscopy include the level of oxidation and whether the graphene oxide is present as single, double or few layer material. The ratio of the D and G peak intensities (ID/IG) can be used to estimate the distance between defects, where the term defects refers to disruption in the bonding structure observed for pristine graphene. When analysing graphene oxide, the number of defects is expected to be high as each oxygen functional group on the surface increases the amount of sp3 hybridisation and therefore reduces sp2 hybridisation.

Recent raman spectroscopy carried out on William Blythe’s graphene oxide proved that the material was fully oxidised with an ID/IG ratio of about 1, which is fairly typical for graphene oxide. An estimation of the number of layers present can be given by comparing the area of the D and G peaks to the area of the silicon substrate peak (ca 950 cm-1). Coupling with an SEM image and applying false colour, it has been possible to illustrate the presence of large quantities of single layer graphene oxide. While some 2 layer and 3+ layer material is present, based on the flake shapes and the nature of spin coating, it is thought that these areas are more likely to be flake overlaps rather than multilayer graphene oxide.

The raman analysis carried out on William Blythe’s graphene oxide shows that the graphene oxide manufactured readily exfoliates into monolayers in aqueous dispersions. This has previously been indicated by the ease of dilution. If you have any questions about this analysis or how you can incorporate graphene oxide into your work, please get in touch.

Have you recently seen a paper related to graphene oxide research that you think the GOgraphene team would be interested in sharing?

The GOgraphene team have started posting entries to the GOgraphene blog about papers they have found particularly interesting, be that for the promising results achieved by the researchers, the application area focussed on or the approach taken to the research.

As a company, William Blythe has a strong history of manufacturing products to tight specifications for multiple applications, with materials tuned for their specific end use. By comparison to the existing William Blythe portfolio, graphene oxide is therefore fairly unique. While the material can be tuned for specific applications through both functionalisation and physical property manipulation, the requirements of graphene oxide in each application are not yet well understood. As a result, graphene oxide is considered applicable to many research areas in its standard form. This results in a huge diversity of application sectors interested in graphene oxide materials.

The GOgraphene team like to stay up to date with graphene oxide research which is being carried out across the globe and have taken to writing brief overviews of some of their favourite pieces. The team are always looking to increase both the breadth and depth of their application knowledge around this material, so if you would like to recommend a paper to the team please let us know – if we really like it we might even include it in a future blog post!