6 research outputs found
Preparations and Electrochemical Characterizations of Conductive Porphyrin Polymers
5,10,15,20-TetrakisÂ(4-aminophenyl)Âporphyrin
(TAPP) undergoes oxidative
polymerization to form electronically conductive, nanofibrous structures
in which the porphyrin units are linked by phenazine bridges. Polymerizations
by chemical oxidation, electrochemical oxidation, and interfacial
oxidative polymerization are described. Poly-TAPP (pTAPP) films have
been characterized using scanning electron microscopy, cyclic voltammetry,
electrochemical impedance spectroscopy, and UV–vis spectroscopy.
The polymer morphology is consistently nanofibrous, with some differences
depending on the specific synthetic method. The polymer films show
distinctive electrochromism at different redox and protonation states.
A Pourbaix diagram correlates the proposed redox and protonation states
of the polymer with applied potential, pH, and perceived color of
the film. pTAPP shows the lowest resistance to oxidative doping/dedoping
at low pH and potentials between +0.4 and +0.5 V vs Ag/AgCl
Achieving Smart Photochromics Using Water-Processable, High-Contrast, Oxygen-Sensing, and Photoactuating Thiazolothiazole-Embedded Polymer Films
Water-soluble dipyridinium thiazolo[5,4-d]thiazole
(TTz) compounds are incorporated into inexpensive poly(vinyl alcohol)
(PVA)/borax films and exhibit fast (<1 s), high-contrast photochromism,
photofluorochromism, and oxygen sensing. Under illumination, the films
change from clear/yellow TTz2+ to purple TTz•+ and then blue TTz0. The contrast and speed of the photochromism
are dependent on the polymer matrix redox properties and the concentration
of TTz2+. The photoreduced films exhibit strong, near-infrared
light (1000–1500 nm) absorbances in addition to visible color
changes. Spectroscopic ellipsometry was used to establish the complex
dielectric function for the TTz2+ and TTz0 states.
Incorporating non-photochromic dyes yields yellow-to-green and pink-to-purple
photochromism. Additionally, when illuminated, reversible photoactuation
occurs, causing mechanical contraction in the TTz-embedded films.
The blue film returns to its colorless state via exposure to O2, making the films able to sense oxygen and leak direction
for smart packaging. These films show potential for use in self-tinting
smart windows, eyeglasses, displays, erasable memory devices, fiber
optic communication, and oxygen sensing
Achieving Smart Photochromics Using Water-Processable, High-Contrast, Oxygen-Sensing, and Photoactuating Thiazolothiazole-Embedded Polymer Films
Water-soluble dipyridinium thiazolo[5,4-d]thiazole
(TTz) compounds are incorporated into inexpensive poly(vinyl alcohol)
(PVA)/borax films and exhibit fast (<1 s), high-contrast photochromism,
photofluorochromism, and oxygen sensing. Under illumination, the films
change from clear/yellow TTz2+ to purple TTz•+ and then blue TTz0. The contrast and speed of the photochromism
are dependent on the polymer matrix redox properties and the concentration
of TTz2+. The photoreduced films exhibit strong, near-infrared
light (1000–1500 nm) absorbances in addition to visible color
changes. Spectroscopic ellipsometry was used to establish the complex
dielectric function for the TTz2+ and TTz0 states.
Incorporating non-photochromic dyes yields yellow-to-green and pink-to-purple
photochromism. Additionally, when illuminated, reversible photoactuation
occurs, causing mechanical contraction in the TTz-embedded films.
The blue film returns to its colorless state via exposure to O2, making the films able to sense oxygen and leak direction
for smart packaging. These films show potential for use in self-tinting
smart windows, eyeglasses, displays, erasable memory devices, fiber
optic communication, and oxygen sensing
Achieving Smart Photochromics Using Water-Processable, High-Contrast, Oxygen-Sensing, and Photoactuating Thiazolothiazole-Embedded Polymer Films
Water-soluble dipyridinium thiazolo[5,4-d]thiazole
(TTz) compounds are incorporated into inexpensive poly(vinyl alcohol)
(PVA)/borax films and exhibit fast (<1 s), high-contrast photochromism,
photofluorochromism, and oxygen sensing. Under illumination, the films
change from clear/yellow TTz2+ to purple TTz•+ and then blue TTz0. The contrast and speed of the photochromism
are dependent on the polymer matrix redox properties and the concentration
of TTz2+. The photoreduced films exhibit strong, near-infrared
light (1000–1500 nm) absorbances in addition to visible color
changes. Spectroscopic ellipsometry was used to establish the complex
dielectric function for the TTz2+ and TTz0 states.
Incorporating non-photochromic dyes yields yellow-to-green and pink-to-purple
photochromism. Additionally, when illuminated, reversible photoactuation
occurs, causing mechanical contraction in the TTz-embedded films.
The blue film returns to its colorless state via exposure to O2, making the films able to sense oxygen and leak direction
for smart packaging. These films show potential for use in self-tinting
smart windows, eyeglasses, displays, erasable memory devices, fiber
optic communication, and oxygen sensing
Achieving Smart Photochromics Using Water-Processable, High-Contrast, Oxygen-Sensing, and Photoactuating Thiazolothiazole-Embedded Polymer Films
Water-soluble dipyridinium thiazolo[5,4-d]thiazole
(TTz) compounds are incorporated into inexpensive poly(vinyl alcohol)
(PVA)/borax films and exhibit fast (<1 s), high-contrast photochromism,
photofluorochromism, and oxygen sensing. Under illumination, the films
change from clear/yellow TTz2+ to purple TTz•+ and then blue TTz0. The contrast and speed of the photochromism
are dependent on the polymer matrix redox properties and the concentration
of TTz2+. The photoreduced films exhibit strong, near-infrared
light (1000–1500 nm) absorbances in addition to visible color
changes. Spectroscopic ellipsometry was used to establish the complex
dielectric function for the TTz2+ and TTz0 states.
Incorporating non-photochromic dyes yields yellow-to-green and pink-to-purple
photochromism. Additionally, when illuminated, reversible photoactuation
occurs, causing mechanical contraction in the TTz-embedded films.
The blue film returns to its colorless state via exposure to O2, making the films able to sense oxygen and leak direction
for smart packaging. These films show potential for use in self-tinting
smart windows, eyeglasses, displays, erasable memory devices, fiber
optic communication, and oxygen sensing