Dissertation/Thesis Abstract

Experimental and Modeling Studies of Pattern Growth and Pattern Invasion in Heterogenous Reaction-Diffusion Systems
by Gaskins, Delora K., Ph.D., Brandeis University, 2018, 110; 10792745
Abstract (Summary)

Experimental studies of pattern formation are carried out in the aqueous chlorine dioxide-iodine-malonic acid (CDIMA) oscillating chemical reaction in an open configuration and in the reverse microemulsion Belousov-Zhabotinsky-Aerosol OT (BZ-AOT) oscillating chemical reaction in a closed configuration. These systems form patterns in space and time because of the wave, Turing, and Hopf instabilities.

In the first system, the addition of the halides bromide and chloride changes the wavelength of the Turing patterns by up to five times the natural wavelength of the pattern. This result has significance because the largest previous increase was no more than a factor of two and was unable to be achieved within a single experiment. These changes were able to be qualitatively reproduced with a realistic chemical model.

In the second system, multiple invasion (Turing invading bulk oscillations) styles were observed. In addition, a modulated standing wave pattern was observed to invade a bulk oscillation domain. This pattern in turn was replaced as spirals were formed. This "death" by spiral formation was qualitatively reproduced using a chemical toy model.

Additionally, patterns were observed when the BZ-AOT system (bubble-free, and non-bubble free) was incorporated into a membrane. A microemulsion-based organogel that is stable in the reacting BZ-AOTmedium was also synthesized. These are significant steps towards the building of a reactor for the BZ-AOT reverse microemulsion system.

Indexing (document details)
Advisor: Epstein, Irving R.
Commitee: Peacock-Lopez, Enrique, Xu, Bing
School: Brandeis University
Department: Chemistry
School Location: United States -- Massachusetts
Source: DAI-B 79/10(E), Dissertation Abstracts International
Subjects: Chemistry, Physical chemistry
Keywords: Nonlinear dynamics
Publication Number: 10792745
ISBN: 978-0-438-05183-6
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