Browsing by Author "Karabay, Baris"

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Citation - WoS: 13
Citation - 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 Icli; Chemical Engineering; 06. School Of Engineering; 01. Atılım University
Electrochromic 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, 3483-3493
Acid/ Base Doped/ Dedoped Low Band Gap Polymer
(Amer Chemical Soc, 2016) Karabay, Baris; Gokce, Gurcan; Cihaner, Atilla; Icli Ozkut, Merve; Chemical Engineering; 06. School Of Engineering; 01. Atılım University
[No Abstract Available]
Citation - WoS: 48
Citation - Scopus: 49
Elemental Sulfur-Based Polymeric Materials: Synthesis and Characterization
(Wiley-blackwell, 2016) Salman, Mohamed Khalifa; Karabay, Baris; Karabay, Lutfiye Canan; Cihaner, Atilla; Chemical Engineering; 06. School Of Engineering; 01. Atılım University
New elemental sulfur-based polymeric materials called poly(sulfur-random-divinylbenzene) [poly(S-r-DVB)] were synthesized by ring opening polymerization via inverse vulcanization technique in the presence of a mixture of o-, m-, and p-diviniylbenzene (DVB) as a cross-linker. A clear yellow/orange colored liquid was obtained from the elemental sulfur melted at 160 degrees C and then by adding various amounts of DVB to this liquid directly via a syringe at 200 degrees C viscous reddish brown polymeric materials were obtained. The copolymers are soluble in common solvents like tetrahydrofuran, dichloromethane, and chloroform, and they can be coated on any surface as a thin film by a spray coating technique. The characterization of the materials was performed by using nuclear magnetic resonance, fourier transform infrared, and Raman spectroscopies. The morphological properties were monitored via scanning electron microscope technique. Thermal analysis showed that an increase in the amount of DVB in the copolymers resulted in an increase in the thermal decomposition temperature. On the other hand, poly(S-r-DVB) copolymers exhibited good percent transmittance as 50% T between 1500 and 13,000 nm in electromagnetic radiation spectrum, which makes them good candidates to be amenable use in military and surveillance cameras. (c) 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43655.
Citation - WoS: 9
Citation - Scopus: 10
From 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 Icli; Chemical Engineering; 06. School Of Engineering; 01. Atılım University
The 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.
Citation - WoS: 50
Citation - Scopus: 57
Furan and benzochalcogenodiazole based multichromic polymers via a donor-acceptor approach
(Royal Soc Chemistry, 2013) Icli-Ozkut, Merve; Ipek, Halil; Karabay, Baris; Cihaner, Atilla; Onal, Ahmet M.; Chemical Engineering; 06. School Of Engineering; 01. Atılım University
Two new furan and benzochalcogenodiazole based monomers, namely 4,7-di(furan-2-yl) benzo[c][1,2,5]-selenadiazole (FSeF) and 4,7-di(furan-2-yl) benzo[c][1,2,5]thiadiazole (FSF), were designed and synthesized via a donor-acceptor-donor approach. The monomers were electrochemically polymerized via potentiodynamic or potentiostatic methods. The monomers and their polymers exhibited lower oxidation potentials (1.16 V and 1.06 V for monomers; 0.93 V and 0.80 V for polymers vs. Ag/AgCl) and red shifts of the whole dual-band absorption spectra upon moving from S to Se. Intramolecular charge transfer properties of the monomers and the polymers were demonstrated by using electroanalytical and optical methods. Also, the polymers PFSeF and PFSF were multicolored at different redox states and have low band gaps of 1.43 eV and 1.61 eV, respectively.
Citation - WoS: 46
Citation - Scopus: 47
A Pure Blue To Highly Transmissive Electrochromic Polymer Based on Poly(3,4-Propylenedioxyselenophene) With a High Optical Contrast Ratio
(Amer Chemical Soc, 2015) Karabay, Baris; Pekel, Lutfiye Canan; Cihaner, Atilla; Chemical Engineering; 06. School Of Engineering; 01. Atılım University
A new derivative of 3,4-propylenedioxyselenophene bearing naphthalenylmethyl appeandages on the bridge, called 3,4-dihydro-3,3-bis((naphthalen-2-yl)methyl)-2H-selenopheno[3,4-b][1,4]dioxepine (ProDOS-Np-2), was synthesized and polymerized via potentiostatic and potentiodynamic methods. The electrochemically obtained polymer film (PProDOS-Np-2) is pure blue at the neutral state and highly transparent at the oxidized state. An increase in the size of the substituents on the bridge resulted in an increase in the optical contrast ratio. Upon moving from naked bridge to benzyl and to naphthalenylmethyl substituents on the bridge center, the optical contrast changed from 51% to 65% and finally to 84%, which is the second highest reported optical contrast ratio in polyselenophene family. When compared to polythiophene analogue, the PProDOS-Np-2 has lower oxidation potential and band gap, higher optical contrast ratio, coloration efficiency, robustness, and stability. The polymer film preserved its properties even after thousands of cycles under ambient conditions.