News — graphene oxide application

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!

A recent study estimates the annual cost of global corrosion as USD 2.5 trillion. As a result, studying ways in which to reduce corrosion is an extensive research field with many papers published each year on the topic. There are many ways to address the issue of corrosion, from using corrosion-resistant materials to applying coatings. Over the past few years, there have been several publications looking at exploiting the barrier properties of graphene oxide in anti-corrosion coatings.

A focus of graphene based anti-corrosion coatings has been the use of CVD (chemical vapour deposition), however on an industrial scale CVD is accompanied by many potential barriers due to the specialist equipment and arrangements which are needed. A recent paper in Applied Nanoscience used a process which is arguably easier to scale – they took reduced graphene oxide and dip coated it onto mild steel. The work used rGO in 1-propanol and used multiple layers to form a good barrier around the mild steel coupon. The authors found that they could reduce the corrosion of uncoated mild steel from 282 mm/year in water at pH 6.0 to 0.107 mm/year with a 5 layer coating of reduced graphene oxide. With just 3 layers of coating, the corrosion rate was still reduced by 98.7%.

The research also looked at their coated mild steel in hydrochloric acid (0.1 N), sodium chloride solution (3.5 wt%) and sodium hydroxide (1 M). In all three solutions a reduction in corrosion was observed compared to the uncoated mild steel. Using three layers of coating, the researchers were able to reduce the corrosion rate compared to the uncoated mild steel coupon in all three solutions. Corrosion in HCl was reduced by 86.9%, in sodium chloride by 99.5% and in sodium hydroxide by 99.2%.

This research has illustrated another major potential application for graphene oxide; reducing corrosion is a key objective for many, with the benefits felt by people around the world. If you are interested in using graphene oxide in your work, please get in touch.

Appl. Nanosci., 2016, 6, 1175-1181

A recent article published earlier this year investigated the use of graphene oxide in nanocomposites for use as drug carriers.

Graphene oxide has been researched in many application areas, one of which is in drug carriers. The high surface area and potential for functionalisation result in the possibility to load drugs onto the graphene oxide nanosheets. While graphene oxide disperses well in aqueous systems, it has been found that in physiological systems it will aggregate, limiting its potential use. To overcome this issue researchers have looked to both functionalisation of the graphene oxide and the formation of nanocomposites with other materials.

Bacterial cellulose has also recently become of interest as a drug carrier for several reasons, including its good biocompatibility and its web-like structure, which allows it to support drugs. The research presented in a recent paper illustrates the benefit of combining graphene oxide with bacterial cellulose. The study focussed on in vitro studies of the release of ibuprofen, comparing ibuprofen on bacterial cellulose to ibuprofen on a bacterial cellulose/graphene oxide composite. At both a neutral and acidic pH, the GO composite material showed a more sustained and controlled release of ibuprofen than when supported on bacterial cellulose alone. This indicates that the presence of graphene oxide aids in providing a more controlled release of the drug.

The study also noted several other interesting differences between the bacterial cellulose only carrier and the GO composite. Using a cell counting kit 8 assay, the research showed that graphene oxide increased the biocompatibility of the bacterial cellulose. Two different GO loadings were studied in the biocompatibility tests, with the lower loading showing superior performance. This indicates that too much graphene oxide is detrimental in terms of biocompatibility in this application, although both loadings did show a higher biocompatibility than the bacterial cellulose on its own. The research also found that it was possible to achieve a higher ibuprofen loading on the GO composite material, even in the lower graphene oxide content nanocomposite.

This research has illustrated multiple benefits to forming nanocomposites of graphene oxide and bacterial cellulose for use as drug carriers. It has provided yet another example of the diversity of research which graphene oxide is currently being investigated in. If you are considering using graphene oxide in your research, please get in touch and a member of the team will be happy to discuss which form of graphene oxide they think would be most appropriate for your research.

Reference: Curr. Appl. Phys. 2017, 17, 249-254

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