Electrochemical diazo sulfonated black phosphorus toward conceptual isolation structure with high air stability and fire safety.

The dispersion problems of black phosphorus (BP) in polymer-based composites can be solved by designing isolation structure. An isolating structural material with functionalized BP nanosheets and polystyrene (PS) microspheres was prepared by molding method. Firstly, the sulfonated BP nanosheets with negative charge were obtained by electrochemical diazo modification (electrochemical diazo modification of BP is first report, and achieved good synchronous stripping and modification effect). The sulfonated BP and the PS microspheres with positive charge were self-assembled to form composite microspheres through strong electrostatic interaction. The prepared composite microspheres were further hot pressed near the glass transition temperature to selectively distribute the BP nanosheets at the interface of the fused PS microspheres. Therefore, the PS-BP isolation structure with uniform dispersion and reasonable distribution was obtained in the PS matrix. Thanks to this unique structure, the maximum heat release rate and smoke production rate reduction of the isolation structure can reach 50.1% and 43.3%, which at an excellent level in the same kind of two-dimensional material based composites. The tensile strength is maximally increased by 71.7% when the filling amount is 1.0 wt%. This simple method provides a new strategy for modifying BP and is expected to be applied to the preparation of high performance polymer-based composites. [Display omitted] • An isolation structure with black phosphorus and polystyrene microspheres is achieved. • The electrochemical diazo modification of black phosphorus is the first report. • The heat release rate and smoke production rate of the isolation structure is significantly reduced. [ABSTRACT FROM AUTHOR]