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Title:The sonochemical synthesis of inorganic and biological materials
Author(s):Grinstaff, Mark William
Doctoral Committee Chair(s):Kenneth S. Suslick
Department / Program:Chemistry
Discipline:Chemistry
Degree Granting Institution:University of Illinois at Urbana-Champaign
Degree:Ph.D.
Genre:Dissertation
Subject(s):Chemistry, Inorganic
Chemistry, Physical
Abstract:Understanding and harnessing the interaction between energy and matter is a basic scientific endeavor. The use of high intensity ultrasound to initiate chemical reactions, as opposed to traditional energy sources such as heat and light, has opened new avenues of research. The mechanism of sonochemistry involves acoustic cavitation: the formation, growth, and collapse of bubbles in a liquid. New biological and inorganic materials can be synthesized using this unusual high energy source.
This thesis is divided into two parts. The first part describes the synthesis, characterization and applications of proteinaceous microspheres. We developed a sonochemical technique to synthesize microspheres filled with water-insoluble whose shell is composed entirely of albumin protein. Scanning electron microscopy, optical microscopy, and particle counting characterization reveals that these microcapsules are spherical with typical concentrations of 1.5 $\times$ 10$\sp9$ microcapsule/mL. The microcapsule synthesized have a narrow Gaussian size distribution (average diameter 2.5 $\pm$ 1.0 $\mu$m). Microcapsule formation is strongly inhibited by free radical traps, by superoxide dismutase (but not by catalase), by an absence of O$\sb2$, and by a lack of free cysteine residues in the protein. The microcapsules are held together by disulfide bonds between protein cysteine residues, and superoxide (sonochemically produced during acoustic cavitation) is the oxidizing agent that cross-links the proteins. These biological materials have many medical uses including drug delivery and contrast agents for magnetic resonance imaging and echosonography.
The second part of my thesis develops the use of ultrasound for the synthesis of unusual inorganic materials. Specifically, we have explored the sonochemical synthesis, characterization, and catalytic reactivity of amorphous iron. Enormous heating and cooling rates of between 10$\sp9$ to 10$\sp{13}$ K/sec are produced during acoustic cavitation. Ultrasonic irradiation of iron pentacarbonyl, a volatile inorganic compound, produces nearly pure amorphous iron. X-ray powder diffraction and electron microdiffraction, transmission electron microscopy, and differential scanning calorimeter techniques showed the iron powder to be amorphous. The amorphous iron is a reactive catalyst for the Fischer-Tropsch hydrogenation of CO and for cyclohexane hydrogenolysis and dehydrogenation.
Issue Date:1992
Type:Text
Language:English
URI:http://hdl.handle.net/2142/20097
Rights Information:Copyright 1992 Grinstaff, Mark William
Date Available in IDEALS:2011-05-07
Identifier in Online Catalog:AAI9236475
OCLC Identifier:(UMI)AAI9236475


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