The Critical Role of Asphaltene Nanoaggregates in Stabilizing Functionalized Graphene in Crude Oil Derivatives

Journal article, 2023

Graphene derivatives have been seen as an additive to improve the material properties of bitumen, such as thermal conductivity, viscoelasticity, and mechanical strength. However, in our previous work, a critical challenge was identified. When graphene derivatives are incorporated into bitumen, it leads to detrimental effects. This is due to the poor phase compatibility of graphene derivatives with asphaltene aggregates, the intrinsic aggregates that give bitumen its characteristic properties. In this work, we focus on tailoring the surface chemistry of graphene, thorough non-covalent functionalization, to achieve phase compatibility with asphaltene aggregates. In addition, the work also focuses on stabilizing this functionalized graphene in bitumen. To achieve this, the graphene was functionalized with -COOH tethers by the Molecular wedging method. Thereafter, the same molecules that form the asphaltene aggregates were used to stabilize the functionalized graphene by embedding the -COOH tethers in the asphaltene aggregates. As a result, graphene functionalized by this strategy was observed to be stable in bitumen and phase compatible with asphaltene aggregates. Thus, a successful environment-friendly strategy was developed to utilize the potential of graphene to improve the material properties of bitumen.