Rapid and High-Yielding Formation of CL-20/DNDAP Cocrystals via Self-Assembly in Slightly Soluble-Medium with Improved Sensitivity and Thermal Stability

In this study, the energetic 2,4,6,8,10,12-hexanitrohexaazaisowurtzitane/2,4-dinitro-2,4-diazapentane (CL-20/DNDAP) cocrystals were successfully fabricated via an efficient self-assembly strategy. The formation processes of CL-20/DNDAP cocrystal in solvents of H₂O, H₂O/methyl acetate, and 2-propanol have been investigated by using the powder X-ray diffraction (PXRD) qualitative/quantitative analysis and scanning electron microscopy (SEM). Both theoretical and experimental studies confirmed that the most satisfying results can be achieved by using 2-propanol at 30 °C with crystallization time of 2 h, with a high yield up to 98.2 %. The addition of sodium dodecyl benzene sulfonate (SDBS) is effective in controlling its morphology with a narrow size distribution. Furthermore, the cocrystal exhibits better thermal stability and improved mechanical sensitivity compared with the one prepared by spray drying method. This work provides a simple and convenient approach for the preparation of energetic cocrystals, and the CL-20/DNDAP cocrystal with high energy and low sensitivity is desirable for various applications.