An Electrochromic
Painter’s Palette: Color
Mixing via Solution Co-Processing
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Abstract
Electrochromic polymers (ECPs) have
been shown to be synthetically
tunable, producing a full palette of vibrantly colored to highly transmissive
polymers. The development of these colored-to-transmissive ECPs employed
synthetic design strategies for broad color targeting; however, due
to the subtleties of color perception and the intricacies of polymer
structure and color relationships, fine color control is difficult.
In contrast, color mixing is a well-established practice in the printing
industry. We have identified three colored-to-transmissive switching
electrochromic polymers, referred to as ECP-Cyan (ECP-C), ECP-Magenta
(ECP-M), and ECP-Yellow (ECP-Y), which, via the co-processing of multicomponent
ECP mixtures, follow the CMY color mixing model. The presented work
qualitatively assesses the thin film characteristics of solution co-processed
ECP mixtures. To quantitatively determine the predictability of the
color properties of ECP mixtures, we estimated mass extinction coefficients
(ε<sub>mass</sub>) from solution spectra of the CMY ECPs and
compared the estimated and experimentally observed color values of
blends via a calculated color difference (Δ<i>E</i><sub>ab</sub>). The values of Δ<i>E</i><sub>ab</sub> range from 8 to 26 across all mixture compositions, with an average
value of 15, representing a reasonable degree of agreement between
predicted and observed color values. We demonstrate here the ability
to co-process ECP mixtures into vibrantly colored, visually continuous
films and the ability to estimate the color properties produced in
these mixed ECP films