This item is only available for download by members of the University of Illinois community. Students, faculty, and staff at the U of I may log in with your NetID and password to view the item. If you are trying to access an Illinois-restricted dissertation or thesis, you can request a copy through your library's Inter-Library Loan office or purchase a copy directly from ProQuest.
Permalink
https://hdl.handle.net/2142/19701
Description
Title
Spectroscopic studies of sonoluminescence
Author(s)
Flint, Edward Baldwin
Issue Date
1990
Doctoral Committee Chair(s)
Kenneth S. Suslick
Department of Study
Chemistry
Discipline
Chemistry
Degree Granting Institution
University of Illinois at Urbana-Champaign
Degree Name
Ph.D.
Degree Level
Dissertation
Keyword(s)
Chemistry, General
Chemistry, Physical
Language
eng
Abstract
Sonoluminescence is the light emitted from liquids during ultrasonic irradiation. This work is the first systematic investigation of sonoluminescence spectra from non-aqueous liquids. Sonoluminescence is caused by acoustic cavitation: the formation, growth, and collapse of bubbles in an acoustic field. The rapid collapse of these bubbles causes near-adiabatic heating of the gas and vapor contents of the bubbles.
Ultrasonic irradiation of alkanes, arenes, and silicone oil under Ar leads to emission from C$\sb2$, C$\sb2$H, and CH. When nitrogen is present emission from CN is observed, and when oxygen is present a continuum assigned to CO$\sb2$ emission is observed. Halocarbons under Ar give rise to emission assigned to Cl$\sb2$. A mechanism is proposed where vapor and gas molecules are fragmented by the high temperatures of the cavitation event. Subsequent reaction of high-energy free radical, atomic, and molecular fragments produces the emitting species.
A study of sonoluminescence spectra from alkali metal salts in primary alcohols was conducted as a test of the use of sonoluminescence as a probe of the cavitation event. The linewidths and peak positions of the resonance lines are independent of cavitational temperature. Radicals and atoms formed in the high temperature of the cavitation event were proposed to diffuse into a heated liquid shell surrounding the collapsed bubble, where they reduce and excite the alkali metal cations.
Synthetic spectra of the C$\sb2$ Swan band (d$\sp3\pi\sb{\rm g}$-a$\sp3\pi\sb{\rm u}$) were calculated to model the sonoluminescence spectra and determine the temperature of the cavitation event. Synthetic spectra were compared to sonoluminescence spectra from silicone oil under Ar. For the $\Delta\nu$ = +1 band, T = 4900 K; for the $\Delta\nu$ = 0 band, T = 5125 K; and by comparison of the two bands, T = 5200 K. The average of these determinations yields an effective temperature of the emitting C$\sb2$ in the cavitation event of T = 5050 $\pm$ 150 K.
Sonoluminescence spectra from solutions of metal carbonyls (M(CO)$\sb6$, M = Cr, Mo) are characterized by atomic emission from the metal. The compounds are decomposed and the atoms are excited by the high temperature of the cavitation event.
Use this login method if you
don't
have an
@illinois.edu
email address.
(Oops, I do have one)
IDEALS migrated to a new platform on June 23, 2022. If you created
your account prior to this date, you will have to reset your password
using the forgot-password link below.
