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Smart Materials Congress 2019
Nano Research and Applications
ISSN: 2471-9838
Page 43
August 01-02, 2019
Dublin, Ireland
Smart Materials and
Structures
8
th
International Conference on
Nano Res Appl 2019, Volume 05
Tungsten oxide based hybrid fibers and thin films for
chromogenic applications
Esra Zayim
Istanbul Technical University, Turkey
A
novel procedure develops to prepare tungsten oxide
thin films and microfibers of the organic/inorganic
blend of tungsten hexachloride and polyvinylpyrrolidone.
Herein, we report on developed procedure offering
several advantages over previously known procedures
in the literature. First, it allows fabrication of films and
microfibers, exhibiting reversible color change. Secondly,
tungsten oxide as nanofibers, microfibers and thin films,
fabricated via this procedure can be applied to numerous
types of surfaces (e.g. paper, glass, metal and so forth)
with different techniques (such as electrospinning,
spin coating, droplet drawing, casting and writing ink).
Lastly, these materials have large optical modulation
and possess long memory with superior life-time. In
overall, we believe that this procedure is a novel avenue
to prepare reversible chromic materials, with superior
properties.The electrospun microfibers represent color
alteration under UV lamp acting as a UV detector and
return to their original state after a while when the UV
lamp is witched off. It is worth noting that reversible
fully coloration process takes about 3 minutes while the
bleaching process takes about 3 hours, which indicates
that the photochromic fiber has a good memory effect.
More importantly, the color- cycle of the material is
reversible and it retains its durability and reversibility over
long period of time (i.e., several months). Further studies
were performed to understand the behavior of the WO3
thin film as electrochromic device. In order to fabricate
the device, Li based electrolyte was chosen. In overall,
tungsten oxide coating present new opportunities for
non-destructive writable optical memory. Their long-
term stability and environmental durability leads to
develop new organic/inorganic chromic materials that
can be processed from microfibers to large-area solid
films displaying excellent chromic properties.Another
advantage of this blend is applicable to various types of
substrates, such as glass, ITO glass, metal and paper.
The mechanism of reversible color change is presently
elucidated.
ozesra@itu.edu.tr