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Article Citation - WoS: 61Citation - Scopus: 72A Blue To Highly Transmissive Soluble Electrochromic Polymer Based on Poly(3,4-Propylenedioxyselenophene) With a High Stability and Coloration Efficiency(Royal Soc Chemistry, 2011) Ozkut, Merve Icli; Atak, Samed; Onal, Ahmet M.; Cihaner, AtillaThe optical and electrochemical properties of a regioregular and soluble alkylenedioxyselenophene-based electrochromic polymer, namely poly(3,3-didecyl-3,4-dihydro-2H-selenopheno[3,4-b][1,4] dioxepine (PProDOS-C-10), which is synthesized by electrochemical polymerization, are highlighted. It is noted that this unique polymer has a low band gap (1.58 eV) and is exceptionally stable under ambient atmospheric conditions. Polymer films retain 97% of their electroactivity after 40 000 cycles. The percentage transmittance of a PProDOS-C10 film was found to be 56.4% at 638 nm and 55.8% at 700 nm. Furthermore, this novel soluble PProDOS-C10 polymer shows an electrochromic behavior: a color change from pure blue to a highly transparent state in a low switching time (1.0 s) during oxidation, with high coloration efficiencies (328 cm 2 C-1 at 638 nm and 319 cm(2) C-1 at 700 nm) when compared to its thiophene analogue.Article Citation - WoS: 24Citation - Scopus: 25A Novel Conducting Polymer Based on Terthienyl System Bearing Strong Electron-Withdrawing Substituents and Its Electrochromic Device Application(Elsevier Science Sa, 2008) Asil, Demet; Cihaner, Atilla; Algi, Fatih; Onal, Ahmet M.A novel conducting polymer bearing strong electron-withdrawing substituents (EWS) directly attached to the 3,4-positions of the thiophene ring was synthesized by electrochemical polymerization of diethyl 2,5-di(thiophen-2-yl)thiophene-3,4-dicarboxylate (SSS-Diester). The polymer (PSSS-Diester) was characterized by cyclic voltammetry, FT-IR and UV-vis spectroscopy. The polymer has a reversible redox process and demonstrates a stable electrochromic behavior: reddish orange in the neutral state, brown in the intermediate state and green in the oxidized state. Optical density and response time of the dual-type electrochromic device based on PSSS-Diester were found to be 0.23 and 0.6 s at 623 nm, respectively. It is also noteworthy that the device shows good environmental and redox stability (i.e. 94% of the optical activity of the device retained after 500th switch). (c) 2008 Elsevier B.V. All rights reserved.Article Citation - WoS: 22Citation - Scopus: 25Substituent and Heteroatom Effects on the Electrochromic Properties of Similar Systems(Wiley-blackwell, 2012) Icli-Ozkut, Merve; Cihaner, Atilla; Mersini, Jetmire; Onal, Ahmet M.; Cihaner, Atilla; Cihaner, Atilla; Chemical Engineering; Chemical EngineeringElectrochromic polymers called poly(3,4-dihydro-3,3-bis ((naphthalen-1-yl)methyl)-2H-thieno[3,4-b][1,4]dioxepine) (PProDOT-Np-2), poly(3,3-dibenzyl-3,4-dihydro-2H-selenopheno[3,4-b][1,4]dioxepine), and poly(3,3-dibenzyl-3,4-dihydro-2H-thieno[3,4-b][1,4]dioxepine) were synthesized electrochemically and the effect of substituents and heteroatoms on the electrochromic properties were investigated for the similar systems. All polymers show electrochromism from a colored state when neutralized to transmissive when oxidized. Although, increasing bulky size (PProDOT-Np-2) causes lower coloration efficiency (CE) as well as lower optical contrast, the replacement of S atom by Se atom resulted in a lower band gap polymer with a higher CE than its thiophene analog. (c) 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 50: 615- 621, 2012Article Citation - WoS: 94Citation - Scopus: 100A New Soluble Neutral State Black Electrochromic Copolymer Via a Donor-Acceptor Approach(Elsevier, 2010) Icli, Merve; Pamuk, Melek; Algi, Fatih; Onal, Ahmet M.; Cihaner, AtillaTwo donor-acceptor systems, 2-decyl-4,7-bis(3,3-didecyl-3,4-dihydro-2H-thieno[3,4-b][1,4]dioxepin-6-yl)-2H-benzo[d][1,2,3]triazole (1) and 4,7-bis(3,3-didecyl-3,4-dihydro-2H-thieno[3,4-b][1,4]dioxepin-6-yl)-2,1,3-benzoselenadiazole (2) are explored in order to attain a low bandgap black polymer electrochrome, which is highly difficult to attain due to the complexity of designing such materials. Electrochemical polymerization of 1 and 2 in 1:4 monomer feed ratio was performed in a mixture of acetonitrile and dichloromethane solution containing 0.1 M tetrabutylammonium hexafluorophosphate. It was found that electropolymerization provides a processable neutral state black copolymer, (P(1-co-2)), which absorbs virtually the whole visible spectrum (400-800 nm). (P(1-co-2)) is the first low bandgap (1.45 eV) electropolymerized material, which switches from black color (L = 14.3, a = 0.29, b = 0.35) in the neutral state to transmissive grey (L = 39.2, a = 0.29, b = 0.33) in the oxidized state with 15.3% of the transmittance change at 522 nm. Furthermore, it exhibits excellent operational and/or environmental stability under ambient conditions. (c) 2010 Elsevier B.V. All rights reserved.Article Citation - WoS: 2Citation - Scopus: 3Impedance Spectroscopy of N-Substituted Oligo-Oxyethylene Polypyrrole Films(John Wiley & Sons inc, 2008) Cihaner, Atilla; Onal, Ahmet M.The electrochemical properties of neutral (dedoped) and oxidized (doped) poly(1,11-bis(1,1-pyrrole)-3,6,9-trioxaundecane) (poly-I) film electrodes were investigated using cyclic voltammetry and electrochemical impedance spectroscopy (EIS) techniques. Poly-I was deposited on glassy carbon electrode (GCE) from acetonitrile solution containing 5.0 x 10(-3) M 1,11-bis(1,1-pyrrole)-3,6,9-trioxaundecane (I) and 0.1 M LiClO4 supporting electrolyte. Doped poly-I exhibits a single semicircle in its complex-capacitance plots, indicating a single dominant ion transport process, together with high capacitance values. These features make this polymer film a candidate for an energy storage material. Also, poly-I can be a candidate as a sensory material for the detection of Ag+ based on impedance parameters. (C) 2008 Wiley Periodicals, Inc.Article Citation - WoS: 10Citation - Scopus: 10Synthesis and Electropolymerization of Donor-Acceptor Type Monomers Based on Azobenzene-Substituted Thieno[3,4-C]pyrrole Acceptors(Pergamon-elsevier Science Ltd, 2021) Cakal, Deniz; Cihaner, Atilla; Onal, Ahmet M.By using donor-acceptor-donor approach, a new series of photo responsive and electroactive trimeric monomers, namely (E)-5-(4-(phenyldiazenyl)phenyl)-1,3-di(thiophen-2-yl)-4H-thieno[3,4- c]pyrrole-4,6(5H)-dione (T-2-AB ), (E)-1,3-bis(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)-5-(4-(phenyldiazenyl)phenyl)- 4H-thieno[3,4-c]pyrrole-4,6(5H)-dione (E-2-AB ) and (E)-1,3-bis(3,3-didecyl-3,4-dihydro-2H-thieno[3,4- b][1,4]dioxepin-6-yl)-5-(4-(phenyldiazenyl)phenyl)-4H-thieno[3,4-c]pyrrole-4,6(5H)-dione (P-2-AB ), was synthesized and characterized. The oxidation potential of the monomers was controlled by the strength of donor units and the following trend was observed for them: Eox (T-2-AB ) > E-ox (P-2-AB ) > E-ox (E-2-AB ). Also, a similar behavior was observed for their band gap values: 2.53 eV for T-2-AB , 2.18 eV for E-2-AB and 2.28 eV for P-2-AB . The monomers were polymerized successfully via electrochemical methods in order to give electrochromic ambipolar conjugated polymers bearing narrow optical band gaps: 1.71 eV, 1.54 eV and 1.68 eV for PT2-AB, PE2-AB , and PP2-AB, respectively. Also, the polymer films are stable and robust. Moreover, the three monomers and soluble PP(2-)AB polymer exhibited trans to cis photo-isomerization upon irradiation with UV light. In addition, the photoluminescence intensity of the monomers in toluene was found to decrease with increasing acid concentration, which makes them potential candidates to be amenable as pH sensors. (C) 2021 Elsevier Ltd. All rights reserved.Article Citation - WoS: 7Citation - Scopus: 7Electrochemical and optical properties of dicyclohexylmethyl substituted poly(3,4-propylenedioxythiophene) analogue(Wiley, 2018) Cakal, Deniz; Cihaner, Atilla; Onal, Ahmet M.An analogue of disubstituted 3,4-propylenedioxythiophenes, namely 3,3-bis(cyclohexylmethyl)-3,4-dihydro-2H-thieno[3,4-b][1,4]dioxepin (ProDOT-CycHex(2)), was synthesized and its electrochemical polymerization was carried out successfully in an electrolyte solution of 0.1 M tetrabutylammonium hexafluorophosphate dissolved in a mixture of acetonitrile and dichloromethane (3/1: v/v). The corresponding polymer called PProDOT-CycHex(2) has a reduced band gap of 1.85 eV and an electrochromic property: blue/violet when neutralized and highly transparent when oxidized. Also, PProDOT-CycHex(2) film exhibited faster response time (0.7 s) and higher coloration efficiency (769 cm(2)/C) during oxidation when compared to its benzyl substituted analogue. (c) 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46214.Article Citation - WoS: 14Citation - Scopus: 16Electrosynthesis of Polyfuran in Acetonitrile-Boron Trifluoride-Ethyl Ether Mixture and Its Device Application(John Wiley & Sons inc, 2007) Tirkes, Seha; Onal, Ahmet M.Electrochemical polymerization of furan was achieved in acetonitrile/boron trifluoride/ethyl ether (CH3 CN/BF3/EE) mixture in the presence of tetrabutylammonium tetrafluoroborate via constant potential electrolysis at 1.4 V versus Ag/AgCl. Electrochemical behavior of furan was investigated in the same solvent mixture of varying ratios, utilizing cyclic voltammetry. Free-standing polyfuran (PFu) films were obtained in CH3CN/BF3/EE mixture (2/4/4; v/v/v) and characterized using FTIR spectroscopic technique. Spectroelectrochemical behavior of the PFu film was investigated by recording the electronic absorption spectra, in sitn, in monomer-free solution. It is observed that PFu film can be reversibly cycled between -0.1 V (gray) and + 0.6 V versus Ag-wire (gray color); however, this behavior diminishes in the presence of water. Electrochromic device application of PFu film with poly(ethylene dioxythiophene) was also studied. (c) 2006 Wiley Periodicals, Inc.Article Citation - WoS: 21Citation - Scopus: 21Synthesis and Properties of a Novel Redox Driven Chemiluminescent Material Built on a Terthienyl System(Pergamon-elsevier Science Ltd, 2009) Atilgan, Nurdan; Algi, Fatih; Onal, Ahmet M.; Cihaner, AtillaA novel redox driven chemiluminescent material built on a terthienyl system, namely 5,7-di-ethylenedioxythiophen-2-yl-2,3-dihydro-thieno[3,4-d]pyridazine-1,4-dione (ETE-Lum), which is soluble in both organic media and basic aqueous solution was synthesized and characterized. Furthermore, its polymer, PETE-Lum, which is one of the most rare examples of chemiluminescent polymeric materials bearing a pyridazine unit, was obtained successfully by electrochemical means. Both of the materials give chemiluminescence either by treatment with oxidants (H2O2 and/or KMnO4) or by the application of a potential pulse. (C) 2009 Elsevier Ltd. All rights reserved.Article Citation - WoS: 6Citation - Scopus: 6Electrochemical Copolymerization and Characterization of Dianilines Linked by Polyether Bridge With Aniline(Springer, 2010) Tirkes, Seha; Onal, Ahmet M.Copolymer of aniline and triethylene glycol bis(o-aminophenyl) ether was synthesized by constant potential electrolysis. Cyclic voltammogram of the copolymer films recorded in the monomer-free electrolytic solution revealed that the redox behavior of the films approaches to that of poly(triethylene glycol bis(o-aminophenyl) ether) with increasing amount of triethylene glycol bis(o-aminophenyl) in the feed ratio. Copolymerization was investigated by in situ recording the changes in the electronic absorption spectrum during electrolysis. The free standing copolymer film was characterized utilizing Fourier transform infrared spectrometer, and spectroelectrochemical behavior of the copolymer was investigated via in situ UV-vis spectroscopic technique. Besides the electron spin resonance study of the copolymer film, the different morphologies of the polymers were examined by scanning electron microscopy and the copolymerization was confirmed. The temperature dependence conductivity of the copolymer film was measured by four-probe technique in the temperature range of 100-300 K, and the calculated parameters showed that conduction mechanism fits to variable range hopping.
