Unveiling the power of 2D carbon-based electrically conductive adhesive: a comparative analysis on structure and performance

The rise in popularity of carbon-based adhesives is revolutionizing the industry, offering eco-friendly alternatives that can be recycled while protecting the environment from the harmful effects of solder metal. In this ground breaking study, we delve into the impact of different carbon-based conductive fillers on the overall performance of the adhesive. From reduced graphene oxide (rGO) to thermally and chemically expanded graphite (EG), we explore these fillers’ intricate 3D network structure and how they enhance both the final product’s electrical conductivity and mechanical strength. According to the findings of this research, the structure of 3D and interwoven EG plays the prominent role in electrical conductivity. Maintaining the 3D and stable structure after making the composite is due to the structure of EG, which prevents the graphene sheets from falling on top of each other, preventing the interaction of free electrons with vertical sheets. On the other hand, a similar structure was obtained using two separate methods of thermal and chemical expansion, which is optimal in terms of electrical conductivity. Our findings reveal that an adhesive containing 17.5 wt% of EG achieved a volume resistivity of 2.5 Ω cm, showcasing the remarkable conductivity of these materials. The unique 3D network structure improves electrical performance and aids in the curing process by reducing curing enthalpy to 147.19 J g⁻¹, resulting in superior mechanical properties and adhesion. Furthermore, by studying the effects of functional groups and surface characteristics of chemically expanded graphite (CEG), we discovered that sharp edges and wrinkled sheets significantly enhance the adhesive’s tensile strength, surpassing 10.24 ± 1.2 MPa. The Young’s modulus of 96.24 ± 6 MPa represents moderate stiffness while also allowing for flexibility. The results show carbon-based adhesives’ potential and pave the way for a more sustainable product.