气候变化领域集成服务门户(CCPortal): Observations on hygroscopic growth and phase transitions of mixed 1, 2, 6-hexanetriol / (NH4)2SO4 particles: Investigation of the liquid-liquid phase separation (LLPS) dynamic process and mechanism and secondary LLPS during the dehumidification

CCPortal

DOI	10.5194/acp-21-9705-2021
	Observations on hygroscopic growth and phase transitions of mixed 1, 2, 6-hexanetriol / (NH4)2SO4 particles: Investigation of the liquid-liquid phase separation (LLPS) dynamic process and mechanism and secondary LLPS during the dehumidification
	Ma S.; Chen Z.; Pang S.; Zhang Y.
发表日期	2021
ISSN	1680-7316
起始页码	9705
结束页码	9717
卷号	21 期号:12
英文摘要	Atmospheric aerosols consisting of organic and inorganic components may undergo liquid-liquid phase separation (LLPS) and liquid-solid phase transitions during ambient relative humidity (RH) fluctuation. However, the knowledge of dynamic phase evolution processes for mixed organic-inorganic particles is scarce. Here we present a universal and visualized observation of LLPS, efflorescence and deliquescence transitions as well as hygroscopic growth of laboratory-generated mixed 1, 2, 6-hexanetriol / ammonium sulfate (AS) particles with different organic-inorganic mole ratios (OIR Combining double low line 1:4, 1:2, 1:1, 2:1 and 4:1) with high time resolution (0.5 s) using an optical microscope operated with a video camera. The optical images suggest that an inner AS solution phase is surrounded by an outer organic-rich phase after LLPS for all mixed particles. The LLPS mechanism for particles with different OIRs is found to be distinct; meanwhile, multiple mechanisms may dominate successively in individual particles with a certain OIR, somewhat inconsistently with previously reported observations. More importantly, another phase separation in the inner AS solution phase, defined as secondary LLPS here, is observed for OIR Combining double low line 1:1, 1:2 and 1:4 particles. The secondary LLPS may be attributed to the formation of more concentrated AS inclusions in the inner phase and becomes more obvious with decreasing RH and increasing AS mole fraction. Furthermore, the changes in size and number of AS inclusions during LLPS are quantitatively characterized, which further illustrate the equilibrium partitioning process of organic and inorganic components. These experimental results have significant implications for the revelation of complex phase transitions of internally mixed atmospheric particles and evaluation of liquid-liquid and liquid-solid equilibria in thermodynamic models. © 2021 Shuaishuai Ma et al.
语种	英语
scopus关键词	aerosol; concentration (composition); inorganic compound; phase transition; relative humidity; separation; thermodynamics
来源期刊	ATMOSPHERIC CHEMISTRY AND PHYSICS
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/246775
作者单位	The Institute of Chemical Physics, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, 100081, China
推荐引用方式 GB/T 7714	Ma S.,Chen Z.,Pang S.,et al. Observations on hygroscopic growth and phase transitions of mixed 1, 2, 6-hexanetriol / (NH4)2SO4 particles: Investigation of the liquid-liquid phase separation (LLPS) dynamic process and mechanism and secondary LLPS during the dehumidification[J],2021,21(12).
APA	Ma S.,Chen Z.,Pang S.,&Zhang Y..(2021).Observations on hygroscopic growth and phase transitions of mixed 1, 2, 6-hexanetriol / (NH4)2SO4 particles: Investigation of the liquid-liquid phase separation (LLPS) dynamic process and mechanism and secondary LLPS during the dehumidification.ATMOSPHERIC CHEMISTRY AND PHYSICS,21(12).
MLA	Ma S.,et al."Observations on hygroscopic growth and phase transitions of mixed 1, 2, 6-hexanetriol / (NH4)2SO4 particles: Investigation of the liquid-liquid phase separation (LLPS) dynamic process and mechanism and secondary LLPS during the dehumidification".ATMOSPHERIC CHEMISTRY AND PHYSICS 21.12(2021).