Colloidal Stability of Graphene-Based Amphiphilic Janus Nanosheet Fluid

Colloidal behavior is fundamental for many applications. Methods for evaluating the stability of chemically homogeneous nanoparticles have been developed well. However, little attention has been paid to that of amphiphilic Janus nanomaterials that have recently emerged. In polar solvents, the significant influence of hydrophobic interaction complicated the evaluation of stability because of the lack of generally accepted theoretical energy potential for the interaction. To the best of our knowledge, this study is the first to investigate the colloidal stability of graphene-based amphiphilic Janus nanosheets at different salt concentrations and temperatures by developing a theoretical model with an understanding of the chemical and physical properties of the fluid. The model predictions were in good agreement with experimental stability evaluations. This study could also serve as a foundation for understanding the behavior of other amphiphilic Janus nanomaterials, achieving complex structures, and stabilizing the amphiphilic Janus nanomaterials for applications in unfriendly environments, e.g., at high salinities or temperatures.