Understanding the Kinetics of Crystallization of Inorganic Salt Crystals Using Efflorescence Process of Microdroplets
GAO Yu-Yi1, MA Shuai-Shuai2, PANG Shu-Feng1**, ZHANG Yun-Hong1**
1. College of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 102488, China; 2. College of Chemical and Material Engineering, Quzhou University, Quzhou 324000, China
Abstract How to measure the rate of crystalline nucleation and understand the kinetic processes of crystal crystallization are difficult learning tasks in crystal chemistry. Atmospheric aerosol particles, which exist in the form of liquid droplets under high humidity conditions, will undergo a phase transition from liquid droplets to solid particles when the ambient relative humidity (RH) is reduced to a certain threshold range, a process known as aerosol efflorescence, and the humidity at which the phase transition occurs is known as the point of efflorescencerelative humidity (ERH), which is usually considered as the critical humidity for haze to change into gray haze. In this paper, we introduce the measurements of efflorescence and crystallization process kinetics of atmospheric aerosols in scientific research into undergraduate teaching, and introduce how to use attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) to determine the crystallization ratio of aerosol micro-droplet clusters, and to obtain the homogeneous and heterogeneous nucleation rates by using the change of the crystallization ratio with the ambient humidity. The use of this method to obtain data on the nucleation kinetics of aerosol microdroplet crystallization, and the process of analyzing these data, contributes to the teaching of crystallization kinetics in crystal chemistry.
GAO Yu-Yi, MA Shuai-Shuai, PANG Shu-Feng, ZHANG Yun-Hong. Understanding the Kinetics of Crystallization of Inorganic Salt Crystals Using Efflorescence Process of Microdroplets[J]. Chinese Journal of Chemical Education, 2024, 45(18): 118-122.
