Solvent effects on electrosynthesis, morphological and electrochromic properties of a nitrogen analog of PEDOT

Abstract

A new nitrogen analog of 3,4-ethylenedioxythiophene (EDOT), N-methyl-3,4-dihydrothieno[3,4-b][1,4]oxazine (MDTO), was electropolymerized in different solvents (deionized water, acetonitrile, and propylene carbonate) using LiClO4 as the electrolyte. The structure and performance of as-prepared PMDTO polymers were systematically studied by cyclic voltammetry, UV-vis spectroscopy, FT-IR, SEM, thermogravimetry, spectroelectrochemistry and electrochromic techniques. To our surprise, solvents had a major influence on the electropolymerization of MDTO and properties of the resultant polymers, including morphology, electrochemistry, electronic and optical properties, and electrochromics, etc. In aqueous solution, MDTO revealed the lowest onset oxidation potential (0.19 V) than in acetonitrile (0.48 V) and propylene carbonate (0.49 V). However, PMDTO films showed rather poor cycling stability in water, while outstanding stability in acetonitrile and propylene carbonate. Films prepared in propylene carbonate displayed a rather smooth morphology, lower band gap (1.65 eV), higher transparency (97.3%) and a contrast ratio (44.6%) at λ = 466 nm. PMDTO films obtained in acetonitrile showed significantly higher coloration efficiency (169.5 cm(2) C(-1)) than in other two solvents (∼ 97.6 cm(2) C(-1)) with a moderate contrast ratio (24.5%).

Poly(3,4-ethylenedioxyselenophene): effect of solvent and electrolyte on electrodeposition, optoelectronic and electrochromic properties

“…Moreover, high viscosity of PC also slows down the speed of monomer and oligomers during electropolymerization. 34,36 This indicates that MeCN is more suitable medium for polymerization of EDOS as compared to PC similar to previously reported polymerization behaviour of MDTO 36 and terthiophene. 47 In addition to solvent, electropolymerization of EDOS is also inuenced by supporting electrolyte.…”

“…This difference in the electrochemical behaviour due to solvents is explained by slow and smooth growth of longer polymer chains in PC which results in faster electron transfer. 36,51 A similar trend was noticed in the CV of PMDTO lms prepared in MeCN and PC. 36 It is noteworthy to mention that the redox behaviour of PEDOS lms were also considerably inuenced by supporting electrolytes.…”

“…35 Xu and coworkers studied the effect of polymerization solvent on the electrochemical, morphological and electrochromic properties of nitrogen analogue of PEDOT, poly(N-methyl-3,4-dihydrothieno [3,4-b] [1,4]oxazine) (PMDTO). 36 Arteaga and coworkers reported the effect of supporting electrolyte on the conductivity, morphology and electrochemical polymerization of PEDOT. 37 Zhao and coworkers reported the electropolymerization of 3methylselenophene in three different electrolytic medium and studied the redox, morphology and optoelectronic properties of poly(3-methylselenophene).…”

Conducting Polymer Electrodes for Thermogalvanic Cells

“…Not only that, it can be used to study the composition of a compound in which absorption spectra are known. Furthermore, it is used to characterize optical devices such as electrochromic devices (164)(165)(166). In this method, determine the intensity of light ( ) passing through a material and then compare it to the intensity of the light ( ) before it passes through the material at a different wavelength.…”

Supramolecular architectures of iron phthalocyanine Langmuir-Blodgett films: The role played by the solution solvents

“…Different strategies can be employed to produce such structures, but the emphasis has been given to techniques that allow controlling molecular architectures, including Layer-by-Layer [7] physical evaporation, [8] Langmuir and Langmuir-Blodgett films [9][10][11][12]. In these cases, different supramolecular architectures can be achieved by tuning experimental conditions, such as i) deposition methods [1] ii) thermal annealing [13] iii) solvent interaction [14,15] among others. For instance, Xiao et al [16] have shown the influence of different solvents on the morphology and crystallinity of poly(3-hexylthiophene) (P3HT) thin films.…”