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Posted on March 6, 2019 by  & 

Graphene Production. Controlling lateral size.

Graphene-based materials continue to attract significant interest for use in a large variety of products ranging from microelectronics through to large scale applications such as cement and other composites. The properties of graphene-based materials are strongly influenced by the chemical purity of the materials as well as their physical properties.
Graphene oxide is typically soluble and more easily processed than pure graphene. In surface applications, graphene oxide can be deposited onto a substrate and then reduced to graphene. This method has been applied to products such as transparent electrodes and filters. Graphene oxide can though, be used directly in a range of applications where it can impart improved strength, thermal and electrical conductivity to composite materials.
In each application the purity and physical properties of the graphene-based material have a major influence on performance and processing settings. A key factor in the latter is the lateral size of the graphene oxide particles. Currently, most graphene oxide particles available in the market are less than 10 micrometres in size. It has generally proven difficult to make larger particle sizes. Recently, JMC, a leading Korean fine chemical manufacturer, has developed a large scale process to enable graphene oxide to be manufactured in a variety of sizes. JMC's scalable process can control the lateral size of graphene oxide particles from 10 to 40 micrometres while still achieving specifications of over 80% of the material being a single layer. It is expected that having a variety of sizes available to developers will accelerate the development of commercial applications of graphene oxide. Large area graphene oxide is seen as particularly important in applications such as silicon-graphene oxide anode materials for batteries and in moisture barriers.
The development of a large scale graphene oxide production capability has been based on JMC's long history of fine chemical manufacturing. JMC's main product is saccharin, the artificial sweetener. Saccharin is accepted as a safe additive to food, beverages, toothpastes, mouthwashes and pharmaceuticals around the world. JMC's saccharin production facility, in South Korea, handles large quantities of reactive materials every day and has quality controls that ensure that JMC's saccharin is the highest quality in the world. JMC's saccharin production process is completely vertically integrated. It begins with sulfur so all intermediates are manufactured in-house on a scale of over 10 tonnes of final product per day. JMC is therefore an established, large-scale chemical manufacturer that has developed a graphene oxide production capability using existing facilities rather than a start-up looking to scale. In assessing true production potential, reliable and reproducible supply, and product quality, the benefits of working with an established, large-scale manufacturer are considerable.
JMC is also working closely with Professor Joo from Cornell University to further develop processes and identify potential applications for graphene oxide. Professor Joo will be speaking at the IDTechEx Show! on methods to stack graphene oxide via scalable processes. Professor Joo will discuss results on using gas-assisted electrospinning to tailor the folding of large-sized graphene oxide sheets. These networks can then accommodate the volume expansion of silicon nanoparticles in batteries or be completely flattened to give a conformal coating for applications in corrosion prevention.
Meet JMC Corporation on booth M11 at the IDTechEx Show! in Berlin, 10-11 April 2019.
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