Characterizing the hygroscopicity and volatility of single levitated aerosol droplets via optical tweezers-Raman spectroscopy. Issue 5 (23rd September 2022)

• Record Type: Journal Article
• Authors: Tong, Yu-Kai; Fang, Teng; Wu, Zhijun; Hu, Min; Ye, Anpei
• Is Part Of: Environmental science. Volume 1:Issue 5(2022)
• Page Start: 781
• Page End: 789
• Publication Date: 2022-09-23
• Subjects: Environmental sciences; Periodicals; 333.7
• DOI: 10.1039/d2va00175f
• Languages: English
• ISSNs: 2754-7000

Abstract

Abstract : This work constructed an opticals tweezers-Raman spectroscopy system to characterize the size variation of single aerosols and quantify the their hygroscopicity and volatility. Abstract : The hygroscopicity and volatility of airborne particles depict the thermodynamic process of the gas-particle partition of semivolatile organic components, which then have substantial impacts on the atmospheric chemistry and lifetime of aerosols. Characterizing relevant physical and chemical parameters is the base for understanding the aerosol evolution process, analyzing evolution motivation and predicting the evolution path. In this work, we captured single levitated aerosol droplets without any contact using a self-developed aerosol optical tweezers (AOT) system, simulated the hygroscopic-volatilization thermodynamic evolution process of ambient aerosols by changing the relative humidity around the trapped droplet, and measured key thermodynamic parameters via Raman spectroscopy including the particle size, refractive index, diffusion coefficient, volatile flux, and vapor pressure. Moreover, possible phase transitions in the aerosol droplets such as glassy and gel transitions were discussed, which provided an important reference for understanding the behaviors of actual atmospheric aerosols.