Preparation of compact spherulite of 2,2′,4,4′,6,6′-hexanitrostilbene (HNS) via specific adsorption of antisolvent combined with polymer

Abstract

The application value of micro-nano hierarchical structure has been widely recognized in many fields, as it can greatly improve the surface performance of particles. Furthermore, the advantages of micro-nano hierarchical structure also bring new opportunities for the performance regulation of energetic materials, as an important material for both civilian and military applications, whose performance directly affects the application areas. This work developed a novel strategy for controlling the construction of compact spherulite of 2,2′,4,4′,6,6′-hexanitrostilbene(HNS) by utilizing antisolvent specific adsorption to generate noncrystallographic branching combined with the polymer additive to inhibit diffusion. Computational simulations revealed that toluene (TOL) exhibits specific adsorption on the (100) face of HNS through π-π interactions, while the polymer additive (Poly(acrylic acid), PAA) strongly interacts with each crystal face of HNS through hydrogen bonding, effectively inhibiting diffusion. Based on these findings, compact spherulites of HNS were successfully prepared by controlling supersaturation. The HNS spherulites exhibited superior flowability, specific surface area (11.84 m2/g for SP-I, 6.43 m2/g for SP-II), porosity (1.94 % for SP-I and 2.14 % for SP-II), and impact sensitivity (impact energy that can withstand increased from 4 J to 32.5 J for SP-I and to 11 J for SP-II). This work not only validates the effectiveness of antisolvent-induced branching in constructing compact spherulite structures, but also provides valuable insights into controlling crystal morphology. Furthermore, this research offers a promising approach to enhancing the safety and performance of energetic materials.