Black phosphorus-based smart electrorheological fluid with tailored phase transition and exfoliation

[Display omitted] •Black phosphorus (BP) was fabricated by mechanical milling from red phosphorus.•Phosphorene was prepared by ultrasonication of the BP.•The BP and phosphorene-based electro-responsive behavior was identified.•Electrorheological smart fluid can be applied to promising electromechanical device. The effect of phase transition and exfoliation time on electro-responsive behavior of black phosphorus is identified by introducing black phosphorus and phosphorene to electrorheological fluid. Black phosphorus is successfully fabricated by mechanical milling for phase transition from red phosphorus, and phosphorene is fabricated by ultrasonication of the prepared black phosphorus. The morphology, degree of phase transition, and electrical conductivity of black phosphorus and phosphorene are precisely controlled by modifying the duration of both milling and delamination. It can be corroborated from a comprehensive study that the electrical conductivity as well as morphology affect the electro-responsive behaviors of black phosphorus and phosphorene. To the best of our knowledge, this is the first report on the meticulous control of phase transition and the potential of both black phosphorus and phosphorene as candidate materials for lectrorheological fluids. This study may provide understanding of the electro-responsive characteristics of black phosphorus and phosphorene, broadening the perspective of electro-responsive smart fluids.