A Dual Electrochrome of Poly‐(3,4‐Ethylenedioxythiophene) Doped by N,N′‐Bis(3‐sulfonatopropyl)‐4‐4′‐bipyridinium—Redox Chemistry and Electrochromism in Flexible Devices

Abstract

An electrochromic zwitterionic viologen, N,N'-bis(3-sulfonatopropyl)-4-4'-bipyridinium, has been used for the first time for doping poly (3,4-ethylenedioxythiopene) (PEDOT) films during electropolymerization. Slow and fast diffusional rates for the monomer at deposition potentials of +1.2 and +1.8 V, respectively yielded the viologen-doped PEDOT films with granular morphology and with dendrite-like shapes. The dual electrochrome formed at +1.8 V, showed enhanced coloration efficiency, larger electrochemical charge storage capacity, and superior redox activity in comparison to its analogue grown at +1.2 V, thus demonstrating the role of dendritic shapes in amplifying electrochromism. Flexible electrochromic devices fabricated with the viologen-doped PEDOT film grown at +1.8 V and Prussian blue with an ionic liquid-based gel electrolyte film showed reversible coloration between pale and dark purple with maximum coloration efficiency of 187 cm2C(-1) at lambda=693 nm. The diffusional impedance parameters and switching kinetics of the device showed the suitability of this dual electrochrome formed as a single layer for practical electrochromic cells.

Flexible and Tailorable Alkylviologen/Cellulose Nanocrystals Composite Films for Sustainable Applications in Electrochromic Devices

“…To obtain a flexible ECDs, a flexible substrate, polyethylene terephthalate coated with an ITO layer (PET‐ITO) was used. The preparation procedures of electrochromic device were depicted in Scheme b …”

Red to Blue High Electrochromic Contrast and Rapid Switching Poly(3,4-ethylenedioxypyrrole)-Au/Ag Nanocomposite Devices for Smart Windows

“…The benefits of using an ionic liquid as medium, in addition to being a source of counter ions for polymer doping, include a wide electrochemical potential stability window, long shelf life, hydrophobicity, negligible volatility, and, in particular, the possibility of fabricating devices under ambient conditions. [12] Herein, we report for the first time the electropolymerization of PEDOP precursor in a waterproof ionic liquid, 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, followed by incorporation of poly(N-vinyl-2-pyrrolidone) (PVP)-capped Ag or Au nanoparticles in the polymer film to yield PEDOP-Ag and PEDOP-Au nanocomposite films. In the nanocomposite, Ag and Au nanoparticles are slightly charged due to the polymer in Ag(PVP) n /Au(PVP) n surrounding the Ag 0 or Au 0 core, therefore resulting in an electrostatic interaction between oxidized PEDOP and the noble metal nanoparticles.…”

“…Prototype electrochromic devices were fabricated with neat PEDOP, PEDOP-Ag, or PEDOP-Au films as cathode, a Prussian blue (PB) film as anode, and a transparent gel containing 3.3 m 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide with 12 wt % PMMA as the polymer electrolyte by using methods described in the literature. [12,15,16] PB films were grown from a solution of 10 mm K 3 [Fe(CN) 6 ] and 10 mm FeCl 3 in 0.01 n HCl in a two-electrode cell by galvanostatic electrodeposition by applying a fixed current density of 10 mA cm À2 to a SnO 2 :Fcoated glass substrate for 8 min. A rectangular cavity was then created on the PB film by using an acrylic spacer, 250 mm thick and % 0.3 cm wide, and the viscous electrolyte gel was transferred into the cavity with a glass rod and left undisturbed for 1-2 h for air bubbles to escape.…”

Matched‐dual‐polymer electrochromic lenses, using new cathodically coloring conducting polymers, with exceptional performance and incorporated into automated sunglasses

“…To the best of our knowledge and based on an extensive search of the literature, the electrochromic lenses and sunglasses we report herein represent the best visible‐region electrochromic performance for dual‐polymer CP electrochromic systems to date. They also are, to our knowledge, the first practical implementation in working sunglasses, that is, they represent practical, functional, and applied polymers.…”