Enhanced hydrophobicity and photosensitivity of DATNBI/alginate films via ionic cross-linking for near-infrared laser ignition

Based on the characteristics of laser-induced surface ignition, energetic photosensitive films show promising potential to meet the ignition requirements of various energetic materials (EMs). In this study, DATNBI/ferric alginate (DI/FeA), DI/cobalt alginate (DI/CoA), and DI/nickel alginate (DI/NiA) films are fabricated by employing sodium alginate (SA) with a three-dimensional network structure as the film matrix, via ionic cross-linking of SA with Fe 3+ , Co 2+ , and Ni 2+ ions. The study demonstrates that the ionic cross-linking enhances the hydrophobic performance of the films, with the water contact angle increasing from 82.1° to 123.5°. Concurrently, the films' near-infrared (NIR) light absorption improved. Furthermore, transition metal ions facilitate accelerated electron transfer, thereby catalyzing the thermal decomposition of DATNBI. Under 1064 nm laser irradiation, the DI/FeA film exhibits exceptional combustion performance, with an ignition delay time as low as 76 ms. It successfully acts as an NIR laser ignition medium to initiate the self-sustained combustion of CL-20. This study demonstrates the synergistic realization of enhanced hydrophobicity, improved photosensitivity, and promoted catalytic decomposition through microstructural design of the material, providing new insights for the design of additive-free EMs in laser ignition applications. • The polymer sodium alginate as a matrix enhances the structural stability of the film. • Transition metal ion loaded DATNBI films enhance hydrophobicity. • In-situ generated metal oxides accelerate the decomposition and combustion of DATNBI. • Near-infrared laser-ignitable DATNBI films exhibit stable and reliable output energy.