Effect of electrolytes on electrochromic properties and morphology of poly(2,5-dimethoxy aniline) films

Abstract

Poly(2,5-dimethoxyaniline) (PDMA) was electrochemically synthesized in oxalic (H 2 C 2 O 4) nitric (HNO 3) and hydrochloric (HCl) acids and deposited onto flexible indium tin oxide at various synthesis times and deposition potentials as electrochromic materials. The PDMA films were characterized by FT-IRspectrometry, scanning electron microscopy, UV-Vis spectrophotometry and cyclic voltammetry. All PDMA films show reversible colour changes from yellow to green corresponding to the transition from the fully reduced state to the fully oxidized state under potential switching. The surface morphology and thickness of PDMA films depend critically on the type of acids used in the electrochemical polymerization process. The morphology of PDMA are highly porous microfibres (H 2 C 2 O 4 and HNO 3), tiny granular aggregate (HCl) and particle agglomerate depending on the polymerization time. The fastest response time observed via colour changing of 3⋅7 s is obtained from the HCl-PDMA film at 3⋅5 volt and at the synthesis time of 6 min, as primarily due to the thickness of the film. The flexible PDMA film is demonstrated here as a potential candidate to be used in electrochromic devices.

Low Conductive Electrodeposited Poly(2,5-dimethoxyaniline) as a Key Material in a Double Lateral Heterojunction, for Sub-ppm Ammonia Sensing in Humid Atmosphere

“…PDMA films electrodeposited on ITO plates had a broccoli shape structure (Figure ). This porous structure can be explained by the high conductivity of PDMA in its emeraldine salt form that enabled a fast growth on itself, as previously reported for PANI, which lead to fibers of a few hundred nanometers in length …”

Synthesis of Poly (2,5-dimethoxyaniline) and Electrochromic Properties

“…The weight loss at ̴ 280 °C was the decomposition of the dopant anion (oxalate anion). Finally, the decomposition temperature of PDMA backbone was at ̴ 400 °C 40,41 . These results confirm the successful polymerization of the doped-PDMA.…”

“…The morphology appeared as a highly porous microfiber structure, disordered microfiber, and ordered tiny-granular aggregate for the PDMA films synthesized using oxalic acid, nitric acid, and hydrochloric acid, respectively. The PDMA film synthesized by using oxalic acid was a less compact structure because it was the largest doping acid size (C 2 O 4 2-) leading to a larger space within PDMA chain 41 .…”

Electrochromic‐Polymer‐Based Switchable Plasmonic Color Devices Using Surface‐Relief Nanostructure Pixels

“…[3] EC materials, such as transition metal oxides, inorganic non-oxides, and EC polymers, reversibly change colors in response to an externally applied voltage. [9,10] However, after decades of acute research endeavors, the performances of EC-polymer-based displays still remain unsatisfactory, and the major drawbacks include low response speed, limited color gamut, and poor visual color contrasts. [9,10] However, after decades of acute research endeavors, the performances of EC-polymer-based displays still remain unsatisfactory, and the major drawbacks include low response speed, limited color gamut, and poor visual color contrasts.…”

“…[1][2][3][4][5][6][7][8] Among wide range of materials which exhibit electrochromism, EC polymers have attracted remarkable interests for applications in ECDs because of their relatively high optical contrast, ease in the fabrication of large area, stability, low processing cost, low power consumption due to bistable states (doped/dedoped states), and their compatibility with flexible electronics. [9,10] However, after decades of acute research endeavors, the performances of EC-polymer-based displays still remain unsatisfactory, and the major drawbacks include low response speed, limited color gamut, and poor visual color contrasts. Due to the limitations of colors that can be directly attained from EC polymers, full-color images cannot be achieved without the complications of having to use a mixture of several different polymers.…”