Graphene

Graphene, a two-dimensional material composed of carbon atoms arranged in hexagonal lattice, has outstanding physical and chemical properties, i.e. its exceptional electronic mobility. This material is thus promising for many applications in the future. However, if chemical vapour deposition (CVD) is a very promising method for large-scale graphene growth , it is still very challenging to control graphene characteristics.
Our objective is both to develop graphene growth by CVD at atmospheric pressure and moderate temperature (600°C / 850°C) on cobalt and to analyse grown graphene with complementary techniques to determine its physical, chemical and structural characteristics.
A study of the influence of different synthesis parameters on graphene characteristics (number of layer, coverage, defect and crystallite size) has been achieved. By combining the use of commercial cobalt foils with growth temperature of 850°C, a high cooling rate (100°C/min) and a low carbon supply, a continuous graphene film of three layers has been synthesized.

Thesis related to the subject: Olivier Duigou (2015)

As part of the ANR LabCom LACTIF project with the Europrotect company, LICSEN and LEDNA are developing textile materials modified by the coating of graphene compounds conferring electromagnetic stealth properties. This activity is described in more detail in the LEDNA report (and mentioned in their portfolio). A range of formulas meeting the conditions of industrial textile printing was designed and made it possible to achieve conductivity values ​​compatible with electromagnetic shielding applications. The preparation of an optimized formula on a scale of several kg and its application on an industrial tool and on an industrial site made it possible to print 30 m2 of functional textile, demonstrating the potential for scaling up the process (M. Jadoul thesis, 2023). This action will continue during the next period to move towards the integration of these textiles in outfits and by reinforcing broad spectrum performances (microwave/radar frequencies in particular).

Concerning the growth of graphene and its functional use as a conductive coating on textiles, the limitation of the CVD growth temperature linked to the thermal resistance of the fabrics proves to be a difficult obstacle to overcome, as has been shown in the framework of the LabCom LACTIF (thesis M Jadoul, 2023). This field of research requires returning to a more fundamental approach allowing us to understand the processes at work in order to then be able to adjust the synthesis parameters to obtain continuous and quality graphene ensuring electrical and thermal conduction properties. This could be part of a project with a well-defined scope by placing itself in a long-term approach.