Realizing high energy release of nano-boron based MICs by spherical g-C₃N₄ with high crystallinity and abundant cyano group

AbstractTo address the challenges of nano-active component agglomeration and incomplete energy release of boron/copper oxide metastable intermixed composites (B/CuO MICs). In this work, the energetic polyvinyl pyrrolidone- nitrocellulose- cyano modified graphitic carbon nitride semi-interpenetrating-polymer-networks (PVP-NC-g-C₃N₄-CN sIPNs) were constructed and utilized as substrate to fabricate high energy B/CuO MICs, in which the nanoparticles can evenly disperse on the constructed sIPNs via various covalent and non-covalent interaction due to strong polar of cyano group. The constructed sIPNs can maximize the interface contact area between nano-sized B and CuO particles, and supply more active sites for exothermic redox reaction. Meanwhile, the generated gases will blow away the formed molten B₂O₃ and other impurities, thereby facilitating interface contact between active B core and oxygen. Thus, the B/CuO MICs shows the highest combustion heat value (10743.8 ± 191.7 J·g−1) when the contents of PVP, NC and g-C₃N₄-CN-2 are 1.25 wt%, 5.0 wt% and 5.0 wt% respectively, and the calculated B combustion efficiency greatly increase from 25.9% to 99.6%. Besides, the thermal stability, microwave ignition delay time, burn rate, maximum pressure and pressurization rate values were also evaluated and compared with the effect of PVP-NC and PVP-NC-g-C₃N₄ on B/CuO. This work will improve the application of B-based MICs in the fields of military and civilian.