Switchable window based on electrochromic polymers

Abstract

A large contrast ratio (>⌬⌻ ‫ס‬ 60%) and rapid switching (0.3-1 s) electrochromic (EC) polymer device that consists of a laminated two-layer structure between two electrodes was prepared. The new design consists of an indium tin oxide (ITO) glass electrode, a cathodic EC polymer film, a solid electrolyte, and a counterelectrode that replaces the anodic EC polymer and ITO electrode. Four EC polymers including two new EC polymers, Poly[3-methyl-3Ј-propyl-3,4-dihydro-2H-thieno(3,4-b)(1,4)dioxepine] (PProDOT-MePro) and Poly[3,3-diethyl-3,4-dihydro-2H,7H-(1,4)dioxepino(2,3-c)pyrrole] (PProDOP-Et 2 ), were synthesized as cathodic EC polymers. A carbon-based counterelectrode was prepared for comparison with an Au-based counterelectrode. Several kinds of polymer gel electrolytes were prepared for comparison. The devices (windows) were increased in area from 0.028 × 0.04 in. 2, 1 × 1 in.2 to 3 × 3 in.2 Three main components, the EC polymer film, the gel electrolyte, and the counterelectrode, were studied and their optical properties, conductivities, and repeatabilities were compared. The effects of window size on the contrast ratio, switching speed, power usage, and repeatability were studied.

Nanomaterials for Construction Engineering-A Review

“…With a ¼ times [21] reduction of lighting and cooling loads reported makes these windows an indispensable part of the construction architecture. The properties of the electrochromic devices are presented in Table II briefly.…”

“…The room is bought to alternate dimness (opaque) and alternate brightness (transparency) by the mode of switch and intelligent control system, which constitutes the operation of these windows. Due to the mode of working the following chemical reactions [20] takes place:Here WO 3 = tungsten oxide, M + = cation injected from electrolyte, e -= electron, NiO= counter electrode, Ln 2 O 3 : Sn= Indium Tin Oxide.With a ¼ times [21] reduction of lighting and cooling loads reported makes these windows an indispensable part of the construction architecture. The properties of the electrochromic devices are presented in Table II briefly.…”

Smart Coatings

“…Both inorganic transition metal oxides such as W0 3 and organic polymers such as [3,3- 4]dioxepine which requires indium tin oxide and vanadium oxide counter layers are employed (15,16).…”

Solution-processable electrochromic red-to-transmissive polymers with tunable neutral state colors, high contrast and enhanced stability

“…Compared with inorganic counterparts, electrochromic (EC) polymers were paid more attention attributing to their numerous advantages such as vivid colors, adjustable band gap, high contrast ratio and fast response time [1,2]. Recently, in order to realize the applications for large area electrochromic windows [3,4], mirrors [5,6] and displays [7,8], solution-processable electrochromic polymers which can be dissolved in conventional organic solvents and spray-coated on large area substrates are exploited [9,10]. These polymers are also required to possess highly transmissive bleached states [11][12][13].…”