Huang Yunhai, Wang Na, Wang Jingkang, Ji Xiongtao, Li Ao, Zhao Hongtu, Song Wenxi, Huang Xin, Wang Ting, Hao Hongxun
National Engineering Research Center of Industrial Crystallization Technology, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, People's Republic of China.
Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300072, People's Republic of China.
Langmuir. 2024 Aug 20;40(33):17786-17795. doi: 10.1021/acs.langmuir.4c02276. Epub 2024 Aug 9.
Exploring nucleation pathways has been a research hot spot in the fields of crystal engineering. In this work, vanillin as a model compound was utilized to explore the factors influencing different nucleation pathways with or without liquid-liquid phase separation (LLPS). A thermodynamic phase diagram of vanillin in the mixed solvent system of water and acetone from 10 to 55 °C was determined. It was found that the occurrence of LLPS might be related to different nucleation pathways. Under the guidance of a thermodynamic phase diagram, Raman spectroscopy and molecular simulation were applied to investigate the influencing factors of different nucleation paths. It was found that the degree of solvation is a key factor determining the nucleation path, and strong solvation could lead to LLPS. Additionally, the molecular self-assembly evolution during the crystallization process was further investigated by using small-angle X-ray scattering (SAXS) and dynamic light scattering (DLS). The findings indicate that larger clusters with a diffuse transition layer may lead to LLPS during the nucleation process.
