A Novel Spherulitic Self-Assembly Strategy for Organic Explosives: Modifying the Hydrogen Bonds by Polymeric Additives in Emulsion Crystallization

作者：Zhou, Xiaoqing; Zhang, Qi^*; Xu, Rong; Chen, Dong; Hao, Shilong; Nie, Fude; Li, Hongzhen^*

来源：Crystal Growth & Design, 2018, 18(4): 2417-2423.

DOI：10.1021/acs.cgd.8b00044

• SPHERICAL CRYSTALLIZATION
• CRYSTALS
• AGGLOMERATION
• PARTICLES
• CELECOXIB
• DESIGN
• ACID

A novel strategy to prepare spherical crystals of 2,6-diamino-3,5-dinitropyrazine-1-oxide (LLM-105) has been developed by introducing polymeric additives into the antisolvent emulsion crystallization. The spherical crystals are induced by modifying the intermolecular hydrogen bonds network of LLM-105. The results show that the concentration of polyvinylpyrrolidone (PVP), which acts as a polymeric additive, is a crucial factor to get quite different morphologies of LLM-105 crystal products. X-like shaped crystals have been produced in the absence of PVP. In contrast, spherical crystals have been obtained in the presence of PVP. Importantly, LLM-105 spherulites with a mean particle size of 78.0 mu m can be obtained by adding a proper amount of PVP, which has a narrow size distribution (CV = 31.2). In addition, time-resolved morphological evolution processes of X-like shaped and spherical crystals have been performed. Meanwhile, 1H NMR experiments also have been conducted to understand the intermolecular hydrogen bonds between LLM-105 molecules and the polymer. Inspired by the result of the above experiments, an LLM-105 spherulitic formation mechanism has been proposed. Furthermore, LLM-105 spherulites exhibit more excellent mechanical and safety properties. It is suggested that these spherulites have a great potentiality in the military application. Therefore, this polymer-induced spherical crystallization method is significantly important for the design and fabrication of organic small molecules with spherical shapes.

• 出版日期2018-4
• 单位中国工程物理研究院