Preparation and growth mechanism of micro spherical ammonium dinitramide crystal based on ultrasound-assisted solvent-antisolvent method

Jingjing Li; Rongjie Yang; Tao Zeng; Jinghui Hu; Weiqiang Tang; Zhenhui Liu; Li Gong

doi:10.1016/j.ultsonch.2021.105716

Preparation and growth mechanism of micro spherical ammonium dinitramide crystal based on ultrasound-assisted solvent-antisolvent method

Ultrason Sonochem. 2021 Oct:78:105716. doi: 10.1016/j.ultsonch.2021.105716. Epub 2021 Aug 16.

Authors

Jingjing Li¹, Rongjie Yang², Tao Zeng¹, Jinghui Hu¹, Weiqiang Tang³, Zhenhui Liu¹, Li Gong⁴

Affiliations

¹ National Engineering Research Center of Flame Retardant Materials, School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081, China.
² National Engineering Research Center of Flame Retardant Materials, School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081, China; State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081, China. Electronic address: yrj@bit.edu.cn.
³ National Engineering Research Center of Flame Retardant Materials, School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081, China; State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081, China.
⁴ Jingbo Chemical Research Institute, Shandong Qingdao 256500, China.

Abstract

Micro-sized spherical ammonium dinitramide (ADN) crystals are successfully prepared by a facile ultrasound-assisted solvent-antisolvent recrystallization method without introducing any additives. The influences of the volume ratio of solvent to antisolvent, the antisolvent temperature and the ultrasound power on the micro-morphologies and properties of ADN crystals are studied systematically. The changes of morphology, particle size, crystal structure and melting point of the ADN crystals are characterized through scanning electron microscopy (SEM), laser particle size analyzer (LPSA), X-ray diffraction (XRD) and differential scanning calorimetry (DSC), respectively. The results show that the optimal experimental parameters for the ADN crystal of spherical morphology are as follows: the volume ratio of solvent to antisolvent is 1:50, the antisolvent temperature is 20 ℃, and the ultrasound power is 70 W. The predicted hexagonal-flake and spherical morphologies for the ADN are close to the experimental morphologies. The growth mechanism of the spherical ADN crystal changes with supersaturation of the ADN solution. As the degree of supersaturation increases, the growth models of the spherical ADN change from the spiral growth to the rough growth, and the morphologies of ADN change from the large-sized ADN ball to the small-sized ADN ball.

Keywords: Ammonium dinitramide; Crystal growth; Crystal morphology; Recrystallization; Solvent-antisolvent; Spiral growth model.