%0 Journal Article
%A Alesanco, Yolanda
%A Viñuales, Ana
%A Cabañero, Germán
%A Rodriguez, Javier
%A Tena-Zaera, Ramón
%D 2016
%T Colorless to Neutral Color
Electrochromic Devices Based on Asymmetric Viologens
%U https://acs.figshare.com/articles/journal_contribution/Colorless_to_Neutral_Color_Electrochromic_Devices_Based_on_Asymmetric_Viologens/4055583
%R 10.1021/acsami.6b11321.s001
%2 https://acs.figshare.com/ndownloader/files/6530556
%K PVA-borax gel polyelectrolytes
%K i.e
%K application
%K easy-to-make neutral-grayish color ECDs
%K electrochromic devices
%K electrochromic technology
%K neutral-grayish colorations
%K neutral-colored state
%K device architecture
%K Neutral Color Electrochromic Devices
%K viologen
%K Asymmetric Viologens Electrochromic materials
%K study reports
%X Electrochromic
materials have extensively been investigated because of their potential
fields of application, with a significant growing interest in expanding
the provided colorations. However, among all palette of colors, colorless
electrochromic devices (ECDs) that provide neutral-grayish colorations
with a simple configuration remain a key challenge. The present study
reports on the synthesis of asymmetrically 1-alkyl-1′-aryl-substituted
viologens and their incorporation in PVA-borax gel polyelectrolytes
for ECDs that constitute the simplest device architecture (glass/TCO/EC
gel/TCO/glass). We demonstrate herein that these EC gels based on
single asymmetric viologens provide more neutral-colored state than
their corresponding symmetric viologens (a* and b* ≤ |15|), while maintaining satisfactory colorless
bleached state (%Tb > 70% in the whole
visible range), transmittance changes (i.e., ∼60%) and cyclability
(i.e., ∼15 000 cycles). Additionally, the effect of
the solvent on the observed coloration has also been investigated.
This easy-to-make neutral-grayish color ECDs may significantly extend
the potential of the electrochromic technology, because they adapt
better aesthetically to the surrounding environment, as they are easier
to implement in different applications.
%I ACS Publications