Mussel-inspired poly-norepinephrine coatings as “slippy-sticky interlayer” for fabricating high-energy insensitive energetic composites

Abstract

Inspired by the super-adhesive properties in marine mussel, a desensitized energetic powder constituted of a slippy-sticky polynorepinephrine interlayer and CL-20 microcore is reported. The slow polymerization process enables the extremely smooth and multifunctional thin-coating formed onto the CL-20 surface. Based on the designed composites, the calculated electronic energy values of all 15 optimized structures reveals a spontaneous thermodynamic process and a stronger bonding strength with the increase of polymerization degree. The H50values of NE/CL-20 structure are calculated and show a significant increase for new composite, produced by the bonding of norepinephrine with CL-20, versus pure CL-20. The subsequent experimental results demonstrate that the slippy CL-20@polynorepinephrine structure exhibits a high drop height (H50, 35.5 cm) and a low explosion probability (60 %) than that of pure CL-20, even exhibits a considerable increase and decreases by 13.3 cm and 12 % in turn versus CL-20@polydopamine under the identical experimental conditions. The sensitive simulation results indicate that the shorter NN bond length and lower area percent in electrostatic potential of samples are positively correlated with the decreasing of impact sensitivity. Note that the ultrasmooth bionic interlayer gives the super-adhesive properties of energetic powder, greatly improves the coating degree of 2D material, thereby shows a lower sensitivity and a high detonation heat for the constructed double-coating composites (CL-20@PNE@GO). To sum up, this study will provide an innovative route to construct a high-safety powder based on a bionic sticky interlayer strategy.