2 results
Search Results
Now showing 1 - 2 of 2
Article Citation - WoS: 13Citation - Scopus: 13[1,2,5]thiadiazolo[3,4-g]quinoxaline Acceptor-Based Donor-Acceptor Polymers: Effect of Strength and Size of Donors on the Band Gap(Wiley, 2017) Gokce, Gurcan; Karabay, Baris; Cihaner, Atilla; Ozkut, Merve IcliElectrochromic polymers based on [1,2,5]thiadiazolo[3,4-g]quinoxaline acceptor and thiophene, 3,4-ethylenedioxythiophene and 3,3-didecyl-3,4-proylenedioxythiophene donors, namely poly(6,7-diphenyl-4,9-di(thiophen-2-yl)-[1,2,5]thiadiazolo[3,4-g]quinoxaline) (P1), poly(4-(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)-9-(2,3-dihydrothieno[3,4-b][1,4]dioxin-7-yl)-6,7-diphenyl-[1,2,5]thiadiazolo[3,4-g]quinoxaline) (P2), and poly(4-(3,3-didecyl-3,4-dihydro-2H-thieno[3,4-b][1,4]dioxepin-6-yl)-9-(3,3-didecyl-3,4-dihydro-2H-thieno[3,4-b][1,4]dioxepin-8-yl)-6,7-diphenyl-[1,2,5]thiadiazolo[3,4-g]quinoxaline) (P3), respectively, were electrochemically and/or chemically synthesized and characterized. Electrochemical and optical properties of the polymers were then investigated. The results, which were obtained electrochemically and optically, indicate that the polymers bearing the same acceptor and different donor units have a band gap range of 0.59-1.24 eV depending on the strength and size of the donor units and band gap determination method. A significant finding in this study was the phenomenon that when the acceptor is physically huge, the general rule that a weak donor would have a high band gap whereas a strong donor would have low band gap can be broken due to the torsional angles/steric hindrances involved with physically large donor molecules. (c) 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 3483-3493Article Citation - WoS: 2Citation - Scopus: 2D-A Type Conjugated Polymers in Dual Electrochromic Devices Tuning From Green To Blue Colors(Elsevier Science Sa, 2023) Ozkut, Merve Icli; Onal, Ahmet M.; Cihaner, AtillaIn this study, the electrochemical and electro-optical properties of four different dual electrochromic devices were unraveled. In all devices, soluble donor-acceptor-donor (D-A-D) type conjugated electrochromic polymers based on didecyl substituted 3,4-propylenedioxythiophene and heterodiazole analogs were used, and they were coated on ITO electrochemically for the construction of the electrochromic devices. Because all D-A-D polymers and PEDOT are colorful in their neutral states and colorless in their oxidized states, it is possible to observe one -to-one colors of pure two polymers in their electrochromic devices rather than a mixture of colors. It was observed that devices changed their colors from the tunes of green to blue under applied external voltage. Switching times, coloration efficiencies and stabilities of the electrochromic devices were calculated as ranging from 1.0 to 6.0 s, 133-544 cm2/C and 54-91 %, respectively, after 5000 cycles. The P(PSeP-C10)-P(PNP-C10) device showed the highest coloration efficiency (544 cm2/C) as well as the best optical and electrochemical stabilities among the electrochromic devices after 5000 cycles (91 % and 92 %, respectively).
