CHED 1413 |
| We present the results of laboratory investigations of amorphous and crystalline water ice films grown to simulate ice cloud particles present during summer in the polar upper atmosphere. These films are grown under high-vacuum at temperatures ranging from 30 to 170 K. Infrared spectra of these films are collected using polarized FT-IRRAS (Fourier transform-infrared reflection absorption spectroscopy) in the spectral range 800-4800 cm-1. Absolute film thicknesses, measured using a laser interferometric technique, are combined with measured spectra to calculate n and k, the real and imaginary components of the refractive index. These optical constants, calculated using an iterative Kramers-Krönig analysis, are compared for ices deposited at a range of temperatures and at different growth rates. Variations in these constants can be used to infer the microstructure of ice substrates used for investigating heterogeneous reactions on water ice particles. |
|
Undergraduate Research Poster Session: Physical Chemistry
2:00 PM-4:00 PM, Monday, March 26, 2007 Hyatt Regency Chicago -- Riverside Center, Poster
Division of Chemical Education |