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Did you know that the GOgraphene team are starting a newsletter, dedicated to bringing graphene oxide news and research straight to your inbox?

The GOgraphene team are always researching new aspects of their graphene oxide products, carrying out work from additional analysis to developing new derivatives and product offerings. To generate the most relevant data from their products, ensuring their research is focussed on developing real benefits to the product range, the GOgraphene team dedicate time to literature searches. With research around graphene related materials so diverse, the number of research groups working with graphene oxide is phenomenal. As a result, a huge volume of academic papers are published each month on the potential use and benefits of graphene related materials. While considering multiple application sectors, the GOgraphene team therefore read many fascinating papers on the real-world applications we might expect to see graphene oxide used in over the coming years. The GOgraphene team recently decided that their online blog would be the ideal place to start sharing some of the papers they had found the most interesting. Based on the positive feedback, GOgraphene have decided to launch a newsletter, linking all those subscribed to a selection of GOgraphene’s recent news and favourite research. The newsletter will cover a variety of topics, ranging from interesting research the team have come across through to research and product information developed by the GOgraphene team.

The first newsletter will be released in April, to sign up click here, scroll to the bottom of the page and enter your email address.

William Blythe is well established as a supplier of flame retardants and smoke suppressants, which results in a specific interest within the team for graphene oxide research connected to this application area. A recent paper published in RSC Advances looked at the use of graphene oxide materials as flame retardants and smoke suppressants in flexible polyurethane foam (FPU).

FPU is often used in furniture to make it more comfortable, however the flammability of the material means that these items can lead to small fires spreading rapidly. This results in items containing FPU posing a significant threat in the instance of a fire.

Research using graphene oxide containing multilayer films on FPU to examine smoke suppression and flame retardation has led to interesting results. The paper focused on cone calorimetry as a test method to compare the materials and examined both graphene oxide and reduced graphene oxide. The results obtained via TGA (thermogravimetric analysis) demonstrate a higher thermal stability for FPU coated with rGO compared to GO. This can be explained by considering the fact that GO would be converting to rGO in the test. When comparing to uncoated FPU, both the rGO and GO coated FPU samples showed a reduction in PHRR (peak heat release rate), peak SPR (smoke production rate) and TSR (total smoke release), indicating the films provide a positive physical barrier effect. The thickness of the coating is believed to be important because a thicker coating leads to a more “tortuous path” for the gaseous byproducts to pass through, slowing down their progress.

This application not only holds special interest within the team at William Blythe, but it is also another example of how diverse the field of graphene oxide application development is. If you are interested in using graphene oxide in your research, please let us know and we would be happy to discuss which form is most likely to suit your research.

Reference: RSC Adv. 2016,6, 114304-114312

William Blythe currently offer two different solid forms of graphene oxide through the GOgraphene webshop; a powder and a flake.

Both products are formed from the aqueous dispersions of graphene oxide manufactured at William Blythe Ltd, and both products meet the same rigorous quality standards as all William Blythe products. We are often asked if there is any difference between these two products, and if so what those differences are. The simple answer to these questions is that while they are different, the differences allow the user to pick the product most suitable for their work rather than one being better than the other.

The flake and the powder are different products because of the drying technique used to produce them, which in turn leads to differences in the properties of the materials. GOgraphene’s graphene oxide powder is best described as a fine brown dust, which will disperse easily with minimal energy input. GOgraphene’s graphene oxide flake is visually different – the flakes are dark brown-amber discs with a diameter of 0.3-0.7 cm. Our graphene oxide flake has been specifically developed to allow researchers who cannot handle dusty solids to work with graphene oxide in non-aqueous systems.

The difference in physical form of these two materials affects the dispersibility of the products. The powder has a higher surface area by definition, this means it is easier to disperse. The flake can be considered as compacted graphene oxide layers; which water molecules need to intercalate between in order to form a dispersion. According to the work carried out by the GOgraphene team, there is no difference in the dispersion stability based on the solid form used. The difference lies in the ease of dispersion; where our graphene oxide powder can be dispersed with a very mild energy input, the flake requires higher energy sonication. For labs which are not equipped with this facility, the powder is undoubtedly the more appropriate option.

To summarise, our graphene oxide flake and freeze dried powder are different products, neither of which are better than the other in all applications. They are complementary products which find purpose in different research programmes. If you would like to speak to a team member regarding which product is more suitable for your work, we would be more than happy to discuss your research.

Graphene oxide has been investigated in thousands of research programmes, to cover many different applications. One potential application for graphene oxide is in antibacterial coatings.

Antibacterial coatings are used to reduce the spread of bacteria, which can help reduce infections. In recent years, the growth of antibiotic resistance has increased the need for antibacterial coatings. These coatings are needed for a variety surfaces, including on medical devices such as catheters.

Research on graphene oxide has proven that it can be effective in bactericidal applications, however the mechanism has not been well understood, preventing the development of specific grades of graphene oxide for this application. A recent article published in ACS Nano focused on this issue, examining different forms of graphene oxide in relation to antibiotic resistant E. Coli.

By examining multiple reduced and hydrated forms of graphene oxide, the research has indicated that the presence of carbon radicals is critical when using graphene oxide as a bactericidal. Higher levels of carbon radicals were achieved in highly hydrated derivatives of graphene oxide – epoxy groups are converted to hydroxyl groups by treating in aqueous alkalized solutions. The tests were carried out on both glass substrates and silicone catheters, both of which would be relevant in a medical setting.

This article is an interesting example for illustrating application development around graphene oxide. Historical graphene oxide research has led to thousands of papers, but commercial applications are struggling to gain traction. To bridge the gap between ideas with great potential and real-world applications, research such as this is essential. The graphene oxide community needs to obtain a fundamental understanding of how graphene oxide works in each application in order to tailor the material used.

If you would be interested in the R&D team at William Blythe working on custom synthesis of a specific graphene oxide grade for your research, please get in touch.

Reference: ACS Nano 2016, 10, 10966-10980

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.