IMMERSION FREEZING OF NON-PROTEINACEOUS BIOLOGICAL AEROSOL PROXIES & ARCTIC AMBIENT PARTICLES

• Main Author: Cory, Kimberly M
• Other Authors: Hiranuma, Naruki, Rogers, William J, Sissom, William D
• Format: Thesis
• Language: English
• Published: 2019
• Subjects: Bioaerosols; Immersion Freezing; Cellulose; Arctic
• Online Access: https://hdl.handle.net/11310/227

Ice-nucleating particles (INPs) are particulates that initiate atmospheric freezing in the temperature range between 0°C and approximately -40°C. Bioaerosols are organic materials, such as bacteria, plants, fungi, and/or archaea, that are dispersed into the atmosphere, in solid or liquid phase, causing ice to form at temperatures as high as -1°C. These particles play an important role in climate science because they alter microphysical properties of a cloud and chemical composition of cloud particles and precipitation. However, the research done on INPs has overlooked the potential for biological influences. There are many sources from which these bioaerosols can come; for example, the aerosols can come from the ocean through the bubble bursting process, river and lakes, areas plagued with drought and heavy winds, or even within the snow in regions that coincide with low temperatures. This study attempted to close that gap in knowledge by researching the ice nucleating capabilities of cellulose and particles collected in the world’s northern most town. The first study is the laboratory-based study to characterize ice nucleation efficiencies of several different cellulose samples, and whether the ice nucleation efficiency is dependent on the physical size of the particle. For cellulose, the project focused on nine laboratory-generated samples that were used as proxies to generate a solution that allowed no interference from other cellulose samples. The nine samples were grouped into two categories, normally microcrystalline (Microcrystalline Cellulose, Fibrous cellulose, ⍺-cellulose, and Arbo-cellulose) and nanocrystalline (Nanocrystalline cellulose, 2,2,6,6-tetramethylpiperidine-1-oxyl Cellulose Nanofibers short length, 2,2,6,6-tetramethylpiperidine-1-oxyl Cellulose Nanofibers standard length, Carboxymethylation Cellulose Nanofibers gel, Carboxymethylation Cellulose Nanofibers powder). To test ice nucleation efficiency, the experiments were run on a Cryogenic Refrigerator Applied Freezing Test (CRAFT) at the ...