Electrochromism

About: Electrochromism is a research topic. Over the lifetime, 13097 publications have been published within this topic receiving 294637 citations.

Electrochromism in photochromic dithienylcyclopentenes.

Abstract: Both photochromic and unprecedented electrochromic properties have been observed for a class of 1,2-bis(3-thienyl)cyclopentene derivatives bearing either a thiophene or a phenyl group attached to the reactive carbon centers. These compounds can be interconverted between their colorless ring-open and colored ring-closed states using UV and visible light, respectively. They can also be catalytically transformed from their ring-closed states to their ring-open states through electrochemical or chemical oxidation.

Electrochromic and optical waveguide studies of corona-poled electro-optic polymer films

Abstract: Real-time monitoring of the corona-poling process that is used to create a bulk second-order nonlinear-optical susceptibility was accomplished by observing electrochromic shifts and intensity decreases of charge-transfer absorption bands in both dye-doped and covalently functionalized polymer films. By measuring small changes in the refractive-index anisotropy, the optical waveguiding technique was demonstrated to be a sensitive measure of the poling-induced order and its relaxation. The guest–host systems were formed from the dyes N,N-dimethylaminonitrostilbene, N,N-dimethylindoaniline (Phenol Blue), and 4-(N-(2-hydroxyethyl)-N-ethyl)-amino-4′-nitroazobenzene (Disperse Red 1), each dissolved in a poly(methyl methacrylate) matrix. The covalently functionalized polymers contained pendant para-nitroaniline (PNA) moieties. The first, poly(N-(4-nitrophenyl)allylamine), was formed from a poly(allylamine) derivative and is called PPNA. The second was based on poly(hydroxystyrene), with PNA attachment occurring between the phenol group and the PNA hydroxyethyl group; this polymer is named PHS-MENA. The final polymer is a linear epoxy (bisphenol A) with the PNA amino N atoms forming a link in the main chain; it is called Bis A-NA. A sample calculation demonstrated the use of experimental electrochromic spectral data to estimate the electro-optic coefficients.

Large‐Scale Fabrication of Pseudocapacitive Glass Windows that Combine Electrochromism and Energy Storage

Abstract: Multifunctional glass windows that combine energy storage and electrochromism have been obtained by facile thermal evaporation and electrodeposition methods. For example, WO3 films that had been deposited on fluorine-doped tin oxide (FTO) glass exhibited a high specific capacitance of 639.8 F g−1. Their color changed from transparent to deep blue with an abrupt decrease in optical transmittance from 91.3 % to 15.1 % at a wavelength of 633 nm when a voltage of −0.6 V (vs. Ag/AgCl) was applied, demonstrating its excellent energy-storage and electrochromism properties. As a second example, a polyaniline-based pseudocapacitive glass was also developed, and its color can change from green to blue. A large-scale pseudocapacitive WO3-based glass window (15×15 cm2) was fabricated as a prototype. Such smart pseudocapacitive glass windows show great potential in functioning as electrochromic windows and concurrently powering electronic devices, such as mobile phones or laptops.