Title page for ETD etd-0509100-092225

Document Type thesis

Author Name Koppetsch, Karsten J.

URN etd-0509100-092225

Title Photodegradation of Organic Photochromic Dyes Incorporated in Ormosil Matrices

Degree MS

Department Chemistry & Biochemistry

Advisors
W. Grant McGimpsey, Advisor
James P. Dittami, Department Head

Keywords
photochromic
spirooxazine
Ormosil

Date of Presentation/Defense 2000-05-03

Availability unrestricted

Abstract
Ormosils (Organically Modified Silicates) have been used in the past as hosts for
various organic molecules. In this work, seven different photochromic dyes most of
which belong to the spirooxazine / merocyanine family were doped into thin films that
were prepared using several increasingly inorganic Ormosil formulations. These dyes
were either physically incorporated into the pores of the film or covalently bound to the
matrix via a siloxane substituent. The dyes, which undergo a reversible color change
upon irradiation, are relatively stable, although they will ultimately degrade after
prolonged exposure to ultraviolet irradiation.

This work focuses on identifying the variables that influence the rate of dye
degradation, including rigidity of the Ormosil matrix, wavelength of irradiation, and the
presence of oxygen. The silylated dyes, which are generally regarded as having reduced
mobility within the pores of the Ormosil, degraded more slowly, suggesting a link
between stability and rotational and translational freedom. Irradiation wavelength also affected dye stability in that limiting exposure to wavelengths in the near UV (and
eliminating visible light) causes the least degradation. This is attributed to the
photostability of the photomerocyanine isomer. Finally, the presence of oxygen was
shown to cause dramatic enhancement in degradation. The mechanisms of each of these
effects are discussed.

Files
koppetsch.pdf

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Document Type	thesis
Author Name	Koppetsch, Karsten J.
URN	etd-0509100-092225
Title	Photodegradation of Organic Photochromic Dyes Incorporated in Ormosil Matrices
Degree	MS
Department	Chemistry & Biochemistry
Advisors	W. Grant McGimpsey, Advisor James P. Dittami, Department Head
Keywords	photochromic spirooxazine Ormosil
Date of Presentation/Defense	2000-05-03
Availability	unrestricted
Abstract Ormosils (Organically Modified Silicates) have been used in the past as hosts for various organic molecules. In this work, seven different photochromic dyes most of which belong to the spirooxazine / merocyanine family were doped into thin films that were prepared using several increasingly inorganic Ormosil formulations. These dyes were either physically incorporated into the pores of the film or covalently bound to the matrix via a siloxane substituent. The dyes, which undergo a reversible color change upon irradiation, are relatively stable, although they will ultimately degrade after prolonged exposure to ultraviolet irradiation. This work focuses on identifying the variables that influence the rate of dye degradation, including rigidity of the Ormosil matrix, wavelength of irradiation, and the presence of oxygen. The silylated dyes, which are generally regarded as having reduced mobility within the pores of the Ormosil, degraded more slowly, suggesting a link between stability and rotational and translational freedom. Irradiation wavelength also affected dye stability in that limiting exposure to wavelengths in the near UV (and eliminating visible light) causes the least degradation. This is attributed to the photostability of the photomerocyanine isomer. Finally, the presence of oxygen was shown to cause dramatic enhancement in degradation. The mechanisms of each of these effects are discussed.
Files	koppetsch.pdf