Publication Date

2020

First Advisor

Andrew Berke

Document Type

Honors Project

Degree Name

Bachelor of Arts

Department

Chemistry

Keywords

Aerosol, Solution, Alcohol, Solvation, Imidazone, Matrix, FTIR-ATR

Abstract

The effect of atmospheric aerosols and their derivatives on the Earth’s climate is not completely understood.1 Previous work has determined that a deeper understanding of solvent environments of aqueous aerosols is necessary to understand the kinetics of certain secondary organic aerosol (SOA) production pathways.2 The study presented explored the make-up of the solvent environments relevant to these reactions. In order to explore these environments a novel method was developed, Articulated Layer Analysis (ALA), which allowed for a more precise reconstruction of the make-up of a solution by allowing for not only determination of which chemicals were present in certain phases of a solution, but also the stratification within said

phases. Using ALA, aqueous aerosol mimicking solutions containing ammonium sulfate, ultra- pure water, glyoxal, and short chain alcohols were tested. It was determined the log(Porg/aq) value

of the solutes, where P is the partition coefficient, could be used to predict phase separation of short chain alcohols and glyoxal in electrolytic solutions. In solutions with negative log(Porg/aq) values, indicating hydrophilicity, the solutes were completely miscible, including glyoxal which also has a negative log(Porg/aq) value. For short chain alcohols with a positive log(Porg/aq) value, a biphasic system was induced with glyoxal in the aqueous layer. These findings have implications for the presence of an alcoholic layer on the exterior of aqueous aerosols which could inhibit the uptake of certain particles impacting the SOA production pathway. This information can be used to inform climate models regarding these pathways.

Rights

2020 Emmaline Reed Longnecker. Access limited to the Smith College community and other researchers while on campus. Smith College community members also may access from off-campus using a Smith College log-in. Other off-campus researchers may request a copy through Interlibrary Loan for personal use.

Language

English

Comments

104 pages : illustrations (chiefly color) Includes bibliographical references (pages 101-104)

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