Dynamics of Liquid-Liquid Phase Separation in Submicrometer Aerosol.

Autor: Kucinski TM; Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States., Ott EE; Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States., Freedman MA; Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States.
Jazyk: angličtina
Zdroj: The journal of physical chemistry. A [J Phys Chem A] 2021 May 27; Vol. 125 (20), pp. 4446-4453. Date of Electronic Publication: 2021 May 17.
DOI: 10.1021/acs.jpca.1c01985
Abstrakt: Nanoscale materials, when compared to their bulk components, possess unique properties. In particular, shifts in phase transitions can occur for submicrometer particles. For instance, small particles do not undergo the process of liquid-liquid phase separation (LLPS). LLPS has applications in emulsions such as Janus particles, controllable morphology to create drug-rich phases during drug delivery, and is often observed in atmospheric aqueous aerosol particles. In atmospheric particles, LLPS is tracked as a function of particle water activity, which is equivalent to the relative humidity (RH) at equilibrium. We probed three organic/inorganic aerosol systems in the range of RH over which phase separation occurs (SRH). Our findings indicate that SRH for submicrometer aerosol particles is lower than for micrometer-sized droplets. These findings show that it may be necessary to update the representation of phase transitions in aerosol particles in climate models. The vast majority of organic/inorganic aerosol particles have submicrometer diameters, and a decrease in SRH for submicrometer particles indicates that the current estimation of phase-separated aerosols may be overestimated. Furthermore, understanding the properties of LLPS at the nanoscale can provide key parameters to describe these systems and may lead to better control of phase separation in submicrometer particles.
Databáze: MEDLINE