利用微液滴的风化过程理解无机盐晶体结晶动力学  

Understanding the Kinetics of Crystallization of Inorganic Salt Crystals Using Efflorescence Process of Microdroplets

作　　者：高宇毅 马帅帅 庞树峰 张韫宏 GAO Yu-Yi;MA Shuai-Shuai;PANG Shu-Feng;ZHANG Yun-Hong(College of Chemistry and Chemical Engineering,Beijing Institute of Technology,Beijing 102488,China;College of Chemical and Material Engineering,Quzhou University,Quzhou 324000,China)

机构地区：[1]北京理工大学化学与化工学院,北京102488 [2]衢州学院化学与材料工程学院,浙江衢州324000

出　　处：《化学教育（中英文）》2024年第18期118-122,共5页Chinese Journal of Chemical Education

基　　金：北京市高等教学学会课题(1330012052301)。

摘　　要：如何测量结晶成核速率、理解晶体结晶动力学过程是晶体化学的学习难点。大气气溶胶颗粒,在高湿度条件下以液态存在,当环境相对湿度(Relative humidity,RH)降低至某个范围内时,颗粒物发生从液态到固态转变,这个过程被称作气溶胶的风化(Efflorescence),发生液-固相变时的RH被称为风化点(Efflorescence relative humidity,ERH),通常也被认为是雾霾转变为灰霾的临界相对湿度。本文将科研中大气气溶胶风化结晶动力学的测量方法引入本科生教学实践,介绍如何利用衰减全反射傅里叶变换红外光谱技术(ATR-FTIR)确定气溶胶微液滴集群的结晶比,并利用结晶比随环境湿度的变化获得均相和异相成核速率。利用这种方法获得气溶胶微液滴结晶成核动力学数据以及对这些数据分析理解,有助于促进晶体化学的教学工作。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 efflorescence relative 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.

关 键 词：微液滴 结晶 ATR-FTIR 均相成核 异相成核 

分 类 号：O74[理学—晶体学]