Molecular-to-continuum scale modeling of aerosols: Atmospheric application and beyond

Author

Ella Ivanova, New Jersey Institute of Technology

Document Type

Dissertation

Date of Award

5-31-2024

Degree Name

Doctor of Philosophy in Chemical Engineering - (Ph.D.)

Department

Chemical and Materials Engineering

First Advisor

Gennady Gor

Second Advisor

Alexei Khalizov

Third Advisor

Edward L. Dreyzin

Fourth Advisor

Richard T. Cimino

Fifth Advisor

Nicole Riemer

Abstract

Aerosol modeling is critical for various applications, such as climate forecasting, air quality, and human health impact assessment. During their lifetime, aerosols undergo a complex evolution, usually divided into several stages — formation, processing, transport, and removal — that occur on different scales. Thus, the choice of modeling methods depends on the stage considered. For example, certain stages of particle formation may require nano-scale modeling while aerosol-cloud interactions span from microscale to mesoscale. This study examines the modeling of aerosol behavior over a wide range of scales, from nano to microscale, with implications to mesoscale.

This dissertation focuses on two categories of aerosols. The first part studies the atmospheric aging of soot particles, which can change their shape from fractal to more spherical form. This morphological transformation profoundly impacts their optical, and transport properties and affinity to water. The second part analyzes chemical warfare agents (CWA), focusing on their thermodynamics and transport properties relevant to aerosols. Due to their toxicity, the experimental measurements on CWAs are limited, leading to the use of less toxic simulants. However, theoretical methods, such as molecular dynamics (MD) simulations, provide a viable alternative for predicting the properties of CWAs and their simulants.

Chapter 1 introduces multiscale aerosol modeling, focusing on the methods and aerosol types considered in this study. Chapters 2 describes the development and refinement of a microphysics model for vapor condensation on convex and concave surfaces of fractal aggregates. Chapter 3 illustrates the application of this model to the processing of soot aggregates in laboratory experiments due to exposure to vapors of trace gas chemicals and water. Chapter 4 shows how the developed capillary condensation framework can be used to improve the description of atmospheric soot aging in a particle-resolved atmospheric model, PartMC-MOSAIC. Chapter 5 examines the fine details of the condensate-surface interactions at the nanoscale. Chapters 6-7 use molecular scale simulations to derive thermodynamic and transport properties of liquids relevant to modeling the formation and evaporation of droplets composed of organophosphorus chemicals. The study concludes with recommendations for improving the integration of multiscale aerosol models and their potential impact on global aerosol modeling.

Recommended Citation

Ivanova, Ella, "Molecular-to-continuum scale modeling of aerosols: Atmospheric application and beyond" (2024). Dissertations. 1821.
https://digitalcommons.njit.edu/dissertations/1821