title: Formation and Transformation Behavior of Sodium Dehydroacetate Hydrates.
abstract: The effect of various controlling factors on the polymorphic outcome of sodium dehydroacetate crystallization was investigated in this study. Cooling crystallization experiments of sodium dehydroacetate in water were conducted at different concentrations. The results revealed that the rate of supersaturation generation played a key role in the formation of the hydrates. At a high supersaturation generation rate, a new sodium dehydroacetate dihydrate needle form was obtained; on the contrary, a sodium dehydroacetate plate monohydrate was formed at a low supersaturation generation rate. Furthermore, the characterization and transformation behavior of these two hydrated forms were investigated with the combined use of microscopy, powder X-ray diffraction (PXRD), Raman spectroscopy, Fourier transform infrared (FTIR), thermal gravimetric analysis (TGA), scanning electron microscopy (SEM) and dynamic vapor sorption (DVS). It was found that the new needle crystals were dihydrated and hollow, and they eventually transformed into sodium dehydroacetate monohydrate. In addition, the mechanism of formation of sodium dehydroacetate hydrates was discussed, and a process growth model of hollow crystals in cooling crystallization was proposed.
authors.affiliation: State Key Laboratory of Chemical Engineering, School of Chemical Engineering and Technology, Tianjin University, No. 92 Weijin Road, Nankai District, Tianjin 300072, China. zhangxia@tju.edu.cn.
authors.forename: Xia
authors.initials: X
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Chemical Engineering, School of Chemical Engineering and Technology, Tianjin University, No. 92 Weijin Road, Nankai District, Tianjin 300072, China. acxie@tju.edu.cn.|Collaborative Innovation Center of Chemical Science and Chemical Engineering (Tianjin), Tianjin 300072, China. acxie@tju.edu.cn.
authors.forename: Chuang
authors.initials: C
authors.lastname: Xie
authors.affiliation: State Key Laboratory of Chemical Engineering, School of Chemical Engineering and Technology, Tianjin University, No. 92 Weijin Road, Nankai District, Tianjin 300072, China. hyhyezi@163.com.
authors.forename: Yaohui
authors.initials: Y
authors.lastname: Huang
authors.affiliation: State Key Laboratory of Chemical Engineering, School of Chemical Engineering and Technology, Tianjin University, No. 92 Weijin Road, Nankai District, Tianjin 300072, China. houbaohong@tju.edu.cn.|Collaborative Innovation Center of Chemical Science and Chemical Engineering (Tianjin), Tianjin 300072, China. houbaohong@tju.edu.cn.
authors.forename: Baohong
authors.initials: B
authors.lastname: Hou
authors.affiliation: State Key Laboratory of Chemical Engineering, School of Chemical Engineering and Technology, Tianjin University, No. 92 Weijin Road, Nankai District, Tianjin 300072, China. yingbao@tju.edu.cn.|Collaborative Innovation Center of Chemical Science and Chemical Engineering (Tianjin), Tianjin 300072, China. yingbao@tju.edu.cn.
authors.forename: Ying
authors.initials: Y
authors.lastname: Bao
authors.affiliation: State Key Laboratory of Chemical Engineering, School of Chemical Engineering and Technology, Tianjin University, No. 92 Weijin Road, Nankai District, Tianjin 300072, China. junbo_gong@tju.edu.cn.|Collaborative Innovation Center of Chemical Science and Chemical Engineering (Tianjin), Tianjin 300072, China. junbo_gong@tju.edu.cn.
authors.forename: Junbo
authors.initials: J
authors.lastname: Gong
authors.affiliation: State Key Laboratory of Chemical Engineering, School of Chemical Engineering and Technology, Tianjin University, No. 92 Weijin Road, Nankai District, Tianjin 300072, China. qxyin@tju.edu.cn.|Collaborative Innovation Center of Chemical Science and Chemical Engineering (Tianjin), Tianjin 300072, China. qxyin@tju.edu.cn.
authors.forename: Qiuxiang
authors.initials: Q
authors.lastname: Yin
authors.affiliation: Department of Chemical and Biochemical Engineering, The University of Western Ontario, London, ON N6A 5B9, Canada. srohani@uwo.ca.
authors.forename: Sohrab
authors.initials: S
authors.lastname: Rohani
mesh_terms: D003460:Crystallization; D008855:Microscopy, Electron, Scanning; D011753:Pyrones / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013059:Spectrum Analysis, Raman; D014867:Water / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D011753:Pyrones; D014867:Water; C027493:dehydroacetic acid
keywords: cooling crystallization; dihydrate; formation mechanism; hollow crystal; monohydrate; sodium dehydroacetate; transformation