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Article Citation - WoS: 9Citation - Scopus: 10From Narrow To Narrower: a Very Low Band Gap [1,2,5]thiadiazolo[3,4-G]quinoxaline Donor-Acceptor Type Electrochromic Polymer(Electrochemical Soc inc, 2017) Gokce, Gurcan; Karabay, Baris; Cihaner, Atilla; Ozkut, Merve IcliThe development of low bandgap polymers (or zero bandgap polymers) is still one of the main goals of scientists and many viable paths have been formulated in order to accomplish this. In this study, a donor-acceptor-donor type electrochromic polymer based on [1,2,5]thiadiazolo[3,4-g]quinoxaline acceptor and selenophene donor units with extremely low bandgap (ranging from 0.21 to 0.60 eV depending on bandgap determination method) is synthesized and characterized electrochemically, optically and colorimetrically. Electrochemical and optical studies showed that the polymer film was susceptible to both n- and p-type doping and has a mustard color in its neutral state, and upon oxidation its color changed to brown, and upon reduction the color is light purple. (C) 2017 The Electrochemical Society. All rights reserved.Article Citation - WoS: 7Citation - Scopus: 6Synthesis and Electrochemical Polymerization of Dithienosilole-Based Monomers Bearing Different Donor Units(Electrochemical Soc inc, 2016) Eken, S.; Ergun, E. G. Cansu; Onal, A. M.Three new donor-acceptor-donor (DAD) type monomers containing five membered heteroaromatic rings as the donor units and the silicon-bridged bithiophene as the acceptor unit were synthesized via Stille cross-coupling reaction. The monomers, 2,6-di(furan-2-yl)-4,4-dioctyl-4H-silolo[3,2-b:4,5-b'] dithiophene (FSiF), 4,4-dioctyl-2,6-di(thiophen-2-yl)-4H-silolo[3,2-b:4,5-b']dithiophene (TSiT) and 4,4-dioctyl-2,6-di(selenophen-2-yl)-4H-silolo[3,2-b:4,5-b'] dithiophene (SeSiSe) were polymerized electrochemically via potential cycling in acetonitrile-tetrabutylammonium perchlorate electrolytic medium. Optical and electrochemical properties of the monomers and their corresponding polymers were investigated and it was found that oxidation potentials of the monomers and optical properties of both monomers and their polymers showed slight variations depending on the heteroatom present in the donor unit. (C) 2016 The Electrochemical Society.Article Citation - WoS: 9Citation - Scopus: 11Propylenedioxy and Benzimidazole Based Electrochromic Polymers(Electrochemical Soc inc, 2016) Cansu-Ergun, E. G.; Onal, A. M.; Cihaner, A.In this study, three acceptor units were synthesized by substituting cyclohexane, cycloheptane and cyclooctane rings at 2-C position of benzimidazole. These acceptor units were coupled with dihexyl substituted 3,4-propylenedioxythiophene (PRODOT-C6) donor segments and the resulting donor-acceptor-donor monomers were polymerized via potentiostatic and potentiodynamic methods to obtain their corresponding conjugated polymers (CP). Monomers and their polymers were investigated in terms of the ring size of the substituent on the acceptor unit and their electrochemical and optical behaviors were reported. The monomers exhibited dual absorption bands (at about 310 nm and 520 nm) due to their donor-acceptor pattern. CP films on indium tin oxide conducting substrate were investigated in a monomer free electrolytic solution. The polymer films exhibited quasi-reversible redox behavior due to doping/dedoping which was accompanied by a reversible electrochromic behavior. All three polymer films showed similar multichromic behaviors: green color in the neutral state, gray in the oxidized state, and brick-red in the reduced state. Band gap values (E-g) were elucidated via both electrochemical and optical methods. Moreover, electrochromic device (ECD) was constructed with one of the polymer films (cyclohexane ring bearing benzimidazole and PRODOT-C6 containing polymer) with poly(3,4-ethylenedioxythiophene) (PEDOT). (C) 2016 The Electrochemical Society. All rights reserved.Article Citation - WoS: 1Citation - Scopus: 1Silver Nanoparticles Added Polymer Film Prepared by Electrochemical Route for Surface Enhanced Raman Scattering Applications(Electrochemical Soc inc, 2019) Khadim, Raisan; Uzun, Ceren; Cihaner, Atilla; Kaya, MuratA simplemethod for the fabrication of stable and highly active surface enhanced Raman scattering (SERS) substrate by exploiting the optical properties of the silver nanoparticles (AgNPs) and organizational characteristics of the polymer is presented. Homogeneous distribution ofAgNPs is achieved with the usage of poly (4,7-di-2,3-dihydrothieno [3,4-b] [1,4] dioxin-5-yl-2,1,3 benzoselena diazole) (PESeE) film coated on the indium tin oxide glass (ITO) surface. The obtained structure ensured the emergence of a large number of hot spots where the localization of electromagnetic energy can result in enhancement of the Raman signal. The effect of the PESeE film thickness, the density of AgNPs added to the polymer film, and the concentration of silver ion solution on the morphology of the substrate and the enhancement of the SERS signal was revealed by using field emission scanning electron microscopy (FE-SEM) and SERS measurements. Enhancement power, homogeneity, and stability of the PESeE-AgNPs substrate were also investigated with measurement of the Raman probe. Spot-to-spot and batch-to-batch reproducibilities of the prepared substrate were calculated as 8.4%, and 10.2% (RSD %) respectively. Due to these properties, PESeE-AgNPs SERS substrate can be a good candidate for the detection and sensor application of various biological and chemical analytes. (C) 2019 The Electrochemical Society.
