Browsing by Author "Icli, Merve"

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Citation - WoS: 7
Citation - Scopus: 8
Anodic Polymerization of 2,5-Di in Ethanol
(Pergamon-elsevier Science Ltd, 2007) Icli, Merve; Cihaner, Atilla; Cihaner, Atilla; Oenal, Ahmet A.; Cihaner, Atilla; Chemical Engineering; Chemical Engineering; 06. School Of Engineering; 01. Atılım University
Poly(2,5-di-(2-thienyl)-furan) (PSOS) was synthesized via anodic polymerization of 2,5-di-(2-thienyl)-furan (SOS) in ethanol solution containing 0.2 M LiClO4 as supporting electrolyte. The electrochemical and spectroelectrochemical properties were investigated using electroanalytical and UV-vis spectroscopic techniques, respectively. The band gap of the polymer film was found as 2.22 eV and the film was successfully switched between black oxidized state and orange neutral state. Fluorescence and electrochemical impedance spectroscopy (EIS) studies were also performed. (C) 2007 Elsevier Ltd. All rights reserved.
Citation - WoS: 142
Citation - Scopus: 157
Donor-Acceptor Polymer Electrochromes With Tunable Colors and Performance
(Amer Chemical Soc, 2010) Icli, Merve; Pamuk, Melek; Algi, Fatih; Onal, Ahmet M.; Cihaner, Atilla; Chemical Engineering; 06. School Of Engineering; 01. Atılım University
To demonstrate the effect of donor (D) and acceptor (A) units on the structure property relationships of electrochromic polymers, design, synthesis, characterization and polymerization of a series of D A type systems, 1-5, based on thiophene, 3,4-ethylenedioxythiophene, and 3,3-didecyl-3,4-dihydro-2H-thieno[3,4-b][1,4]dioxepine as D units and 2,1,3-benzoselenadiazole, 2,1,3-benzothiadiazole and 2-decyl-2H-benzo[d][1,2,3]triazole as A units are highlighted. It is found that these units play key roles on the redox behavior, band gap, neutral state color, and the electrochromic performance (stability, optical contrast, coloration efficiency, and switching time) of the system. It is noted that electropolymerization of these D-A systems provides processable low band gap electrochromes, P1-P5, exhibiting high redox stability, coloration efficiency, transmittance and/or contrast ratio and low response time. Furthermore, P1-P5 reflect various hues of blue and green pallets of the RGB color-space in the neutral state. In particular, it is noteworthy that P5 is an excellent blue-to-colorless polymeric electrochrome, which, to our best knowledge, exhibits the highest optical contrast and coloration efficiency among the D A type systems. The panoramic breadth of the neutral state colors and intriguing features of these polymeric materials further confirm that D A approach allows engineering tunable electrochromes, which hold promise for commercialization of polymeric ROB electrochromics.
Citation - WoS: 94
Citation - Scopus: 100
A New Soluble Neutral State Black Electrochromic Copolymer Via a Donor-Acceptor Approach
(Elsevier, 2010) Icli, Merve; Pamuk, Melek; Algi, Fatih; Onal, Ahmet M.; Cihaner, Atilla; Chemical Engineering; 06. School Of Engineering; 01. Atılım University
Two 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.
Citation - WoS: 4
Citation - Scopus: 4
Template-free microsphere and hollow sphere formation of polymethylanilines
(Wiley, 2009) Icli, Merve; Onal, Ahmet M.; Cihaner, Atilla; Chemical Engineering; 06. School Of Engineering; 01. Atılım University
BACKGROUND: Microsphere and/or hollow sphere formation of methyl-substituted polyaniline derivatives was investigated via chemical polymerization where different sets of conditions were examined. It was found that a variety of parameters (e.g. types and concentrations of monomer and oxidant, polymerization time, solvent with and without acid) have a crucial influence on the morphology of the resulting polyaniline derivatives. RESULTS: Structures with desired morphologies (with or without microspheres and hollow spheres) may be obtained in a controlled manner by changing the parameters. Moreover, the electrochemical and optical properties of the polymers in the presence of acid and/or base were investigated via cyclic voltammetry and UV-visible and electron spin resonance spectroscopic techniques. It is noteworthy that the morphologies of microspheres and/or hollow spheres remained unchanged after repeated acid and base treatments. CONCLUSION: Micro/hollow spherical structures were successfully prepared via chemical polymerization of various substituted anilines by using ammonium persulfate as oxidant. It was found that the type of oxidant and monomers along with the polymerization time are quite important factors for the formation of micro/hollow spheres. Furthermore, hydrogen bond formation does not play any crucial role for the formation of these spheres. Chemically and electrochemically doped/dedoped states of microspheres and/or hollow spheres are very sensitive, and give rapid response towards vapours of HCl and NH3, which makes them amenable for use in sensors. (c) 2009 Society of Chemical Industry