Enhancing energy release and controlled combustion of B-based MICs by the synergistic effect between polyvinyl pyrrolidone and nitrocellulose

To enhance energy release of boron-based metastable intermixed composites (MICs), a series of B-based MICs were constructed successfully by a facile one-step sol-freeze-drying (SFD) method, where copper oxide (CuO) was employed as oxidant. The structure, morphology, chemical state and specific surface area of B-based MICs were investigated by several characterization technologies, and their reactivity and combustion performance were further studied by various experimental tests. The results reveal that B and CuO nanoparticles are dispersed evenly on a nest network braided by the molecular interaction between polyvinyl pyrrolidone (PVP) and nitrocellulose (NC), and the constant volume combustion heat of B-based MICs even reaches 8956.6 ± 76.6 J·g −1 when PVP (1.25 wt%) and NC (5.0 wt%) were added into B/CuO, respectively. The heat value is about 1.7 times as big as pristine B/CuO (5345.5 ± 36.1 J·g −1 ) and approaches to that of raw B NPs (10335.5 ± 507.8 J·g −1 ). Moreover, the condensed phase residues of three composites were collected and confirmed to be Cu and Cu 2 O, while the smallest particle size distribution of product proves that the combustion of B/CuO/NC(NC: 5.0 wt%, PVP: 1.25 wt%) is most complete. So the unique nest network can eliminate particle aggregation, shorten the transfer distance of mass and heat and improve the “solid − solid” thermite reaction between B and CuO NPs. This work will provide a new strategy for promoting the application of boron.