Browsing by Author "Algi, Fatih"

Now showing 1 - 20 of 28

Citation - WoS: 45
Citation - Scopus: 45
An Ambipolar Low Band Gap Material Based on Bodipy and Edot
(Elsevier Science Bv, 2009) Algi, Fatih; Cihaner, Atilla; Chemical Engineering; 06. School Of Engineering; 01. Atılım University
A novel donor-acceptor type conducting polymer based on BODIPY dye as acceptor and EDOT units as donor parts is synthesized electrochemically. The unique combination of BODIPY and EDOT units provides an ambipolar (n- and p-doping processes) low band gap material (4). This is the first example of p-n junction in an organic pi-conjugated material where BODIPY unit is incorporated directly in the main chain. Furthermore, the polymer film exhibits electrochromic behavior upon p-doping: a color change from light violet (neutral) to indigo (oxidized). (C) 2009 Elsevier B.V. All rights reserved.
Citation - WoS: 33
Citation - Scopus: 34
An ambipolar neutral state green polymeric electrochromic
(Elsevier, 2009) Algi, Fatih; Cihaner, Atilla; Chemical Engineering; 06. School Of Engineering; 01. Atılım University
The synthesis and properties of highly stable neutral state green polymeric electrochromic, P1, which is based on 5,8-bis(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)-2,3-di(1H-pyrrol-2-yl)quinoxaline were highlighted. P1 exhibits three well-defined absorption bands with a narrow band gap (1.17 eV). The n- and p-doping (ambipolar) processes suggest that P1 is one of the most promising neutral state green polymers and it can be used in supercapacitors as either cathode or anode electrode material. Apart from the stability and the robustness of the polymer film, P1 shows multi-electrochromic behavior; gray-purple in the reduced form and highly transmissive blue color in the oxidized state. (C) 2009 Elsevier B.V. All rights reserved.
Citation - WoS: 13
Citation - Scopus: 15
Atomistic Engineering of Chemiluminogens: Synthesis, Properties and Polymerization of 2,3-Dihydro Scaffolds
(Springer/plenum Publishers, 2017) Algi, Melek Pamuk; Tirkeş, Seha; Oztas, Zahide; Cihaner, Atilla; Tirkes, Seha; Cihaner, Atilla; Algi, Fatih; Tirkeş, Seha; Cihaner, Atilla; Chemical Engineering; Chemical Engineering; 06. School Of Engineering; 01. Atılım University
Two chemiluminescent compounds containing 2,5-di(thien-2-yl)pyrrole and pyridazine units, namely 5,7-di(thiophen-2-yl)-2,3-dihydro-1H-pyrrolo[3,4-d]pyridazine-1,4(6H)-dione (5) and 6-phenyl-5,7-di(thiophen-2-yl)-2,3-dihydro-1H-pyrrolo[3,4-d]pyridazine-1,4(6H)-dione (6), were successfully synthesized and electrochemically polymerized. The compounds have chemiluminescent properties and glow in the presence of hydrogen peroxide in basic medium. The intensity of the glow can be increased dramatically by using Fe3+ ions, hemin (1.0 ppm) or blood samples (1.0 ppm) as catalyst. The compounds 5 and 6 have one well-defined irreversible oxidation peak at 1.08 V and 1.33 V vs Ag/AgCl, respectively. Electrochemical polymerization of both 5 and 6 were carried out successfully by repeating potential scanning in the presence of BF3. Et2O in an electrolyte solution of 0.1 M LiClO4 dissolved in acetonitrile. The electronic band gaps (E-g) of the polymers P5 and P6 were found to be 2.02 eV and 2.16 eV, respectively. On the other hand, the corresponding polymers are electroactive and exhibited electrochromic features.
Citation - WoS: 19
Citation - Scopus: 18
Design and Synthesis of New 4,4′-Difluoro Based Electrochromic Polymers
(Pergamon-elsevier Science Ltd, 2013) Algi, Melek Pamuk; Tirkes, Seha; Ertan, Salih; Ergun, Emine Gul Cansu; Cihaner, Atilla; Algi, Fatih; Chemical Engineering; 06. School Of Engineering; 01. Atılım University
Design, synthesis, optical and electrochemical properties of two novel 4,4'-Difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) based donor-acceptor compounds, 1 and 2, are reported in order to elucidate the structure-property relationships in BODIPY based materials. Importantly, these compounds provide opportunity to be used as crosslinkers, since they have three electroactive donor sides. Furthermore, these compounds are polymerized successfully via electrochemical polymerization. The corresponding polymers (P1 and P2) are also characterized by using electrochemical and optical methods in monomer-free electrolyte solutions. It is found that both polymers P1 and P2 exhibit reversible oxidation peaks with half wave potentials of 0.70 V and 0.98 V vs. Ag/AgCl, respectively, and they have low optical band gaps (1.88 eV for P1 and 1.72 eV for P2). It is also noted that the polymers exhibit multielectrochromic properties upon doping: P1 can be switched from pink color in the neutral state to blue color in the oxidized state and P2 can be switched from transmissive pink color when neutralized to transmissive blue color when oxidized. (C) 2013 Elsevier Ltd. All rights reserved.
Citation - WoS: 7
Citation - Scopus: 9
Design, Synthesis, Photochromism and Electrochemistry of a Novel Material With Pendant Photochromic Units
(Pergamon-elsevier Science Ltd, 2014) Algi, Melek Pamuk; Cihaner, Atilla; Algi, Fatih; Chemical Engineering; 06. School Of Engineering; 01. Atılım University
In the present work, the synthesis, photochromism and electrochemistry of a novel material 1, 1-(4-[3,4-bis(2,5-dimethyl-3-thienyl)cyclopent-3-en-1-yl]phenyl)-2,5-di-2-thienyl-1H-pyrrole, with pendant dithienylethene (DTE) photochromic units are described. It should be noted that the system I can be reversibly and efficiently switched between open (1o) and closed (1c) states by light in both solution and in the solid poly(methyl methacrylate) matrix. It is also noteworthy that the two isomers (1o and 1c) of this novel system 1 can be smoothly polymerized on ITO by electrochemical means. Surprisingly, the DTE unit in I does not retain its photochemical switching properties after immobilization onto ITO. The morphology of the polymer film was investigated by AFM analysis. Furthermore, it was found that the polymer exhibited remarkable electrochromic features that can be switched from green in the neutral state to violet state under applied external potentials without disturbing the photochromic units. (C) 2014 Elsevier Ltd. All rights reserved.
Citation - WoS: 36
Citation - Scopus: 35
A Diverse-Stimuli Responsive Chemiluminescent Probe With Luminol Scaffold and Its Electropolymerization
(Wiley-v C H verlag Gmbh, 2010) Asil, Demet; Cihaner, Atilla; Algi, Fatih; Onal, Ahmet M.; Chemical Engineering; 06. School Of Engineering; 01. Atılım University
A diverse-stimuli responsive chemiluminescent system, SNS-Lum, and its electropolymerization to give PSNS-Lum, which is the first example of conjugated polymers with pendant luminol arms inducing chemiluminescence in the presence of super oxide radical anion under neutral conditions, are highlighted.
Citation - WoS: 27
Citation - Scopus: 31
Donor-acceptor polymer electrochromes with cyan color: Effect of alkyl chain length on doping processes
(Elsevier, 2012) Celikbilek, Ozden; Icli-Ozkut, Merve; Algi, Fatih; Onal, Ahmet M.; Cihaner, Atilla; Chemical Engineering; 06. School Of Engineering; 01. Atılım University
A new series of donor-acceptor-donor (D-A-D) type compounds consisting of dialkyl substituted 3,4-propylenedioxythiophene and benzothiadiazole units were synthesized and polymerized chemically and electrochemically to investigate the effect of alkyl chain length on the doping process of the conjugated polymers. It was found that the alkyl chain length plays a key role on both doping processes and the solubility of the polymer. It is also noteworthy that this new series of D-A-D electrochromes transmits or reflects the cyan color of the Cyan-Magenta-Yellow (CMY) color space in the neutral state which can be switched to transmissive grey when oxidized. (C) 2011 Elsevier B.V. All rights reserved.
Citation - WoS: 143
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: 45
Citation - Scopus: 46
An Electroactive Polymeric Material and Its Voltammetric Response Towards Alkali Metal Cations in Neat Water
(Pergamon-elsevier Science Ltd, 2008) Algi, Fatih; Cihaner, Atilla; Chemical Engineering; 06. School Of Engineering; 01. Atılım University
The syntheses and characterization of a unique system based on thiophene, pyrrole and benzo-15-crown-5 (SNS-Crown) and its corresponding polymer (PSNS-Crown) are reported. Furthermore, selective, clear and reversible voltammetric responses of the conjugated polymer (PSNS-Crown) film towards the alkali series Li+, Na+ and K+ in both neat water and organic media (ethanol) are described. (c) 2008 Elsevier Ltd. All rights reserved.
Citation - WoS: 20
Citation - Scopus: 22
Electrochemical and Optical Properties of an Azo Dye Based Conducting Copolymer
(Tubitak Scientific & Technological Research Council Turkey, 2009) Cihaner, Atilla; Algi, Fatih; Chemical Engineering; 06. School Of Engineering; 01. Atılım University
The electrochemical and optical properties of a novel conducting copolymer called poly(2,5'-dimethyl-[4-(2,5-di-thiophen-2-yl-pyrrol-1-yl)-phenyl]azobenzene-co-(3,4-ethylenedioxythiophene)) (poly(1-co-EDOT)) are reported. Electrochemically synthesized poly(1-co-EDOT) based on the azo dye has a well-defined and reversible redox couple (0.37 V vs. Ag/AgCl) with good cycle stability. The copolymer film exhibits high conductivity (13 S/cm) as well as electrochromic behavior (magenta when neutralized and transmissive sky blue when oxidized). Furthermore, electro-optically active copolymer film has a low band gap of 1.79 eV with a pi-pi* transition at 555 nm.
Citation - WoS: 43
Citation - Scopus: 45
Electrochemical and Optical Properties of New Soluble Dithienylpyrroles Based on Azo Dyes
(Pergamon-elsevier Science Ltd, 2009) Cihaner, Atilla; Algi, Fatih; Chemical Engineering; 06. School Of Engineering; 01. Atılım University
Two dithienylpyrroles based on azo dyes, namely 2,5'-dimethyl-[4-(2,5-di-thiophen-2-yl-pyrrol-1-yl)-phenyl]azobenzene (SNS-AB2) and 2,5'- dimethyloxy-[4-(2,5-di-thiophen-2-yl-pyrrol-1-yl)phenyl]azobenzene (SNS-AB3), were synthesized and their corresponding polymers (PSNS-AB2 and PSNS-AB3) were successfully obtained via electropolymerization. The monomers have lower oxidation potentials (0.75 V and 0.80V vs. Ag/AgCl for SNS-AB2 and SNS-AB3, respectively) when compared to their analogous. Both monomers exhibited photoisomerism properties under irradiation at 360 nm. During the irradiation process, for example, the color of SNS-AB3 changes from yellow to greenish yellow. The electroactive polymer films have well defined and reversible redox couples with a good cycle stability in both aqueous and organic solutions. The polymer films also exhibited electrochromic behaviors; color changes from yellowish green to dark green for the PSNS-AB2 (lambda(max) = 435 nm and E-g = 2.31 eV) and from mustard color to green for PSNS-AB3 (lambda(max) = 430nm and E-g = 2.34 eV). Furthermore, the soluble polymers demonstrated different hues of yellow and green colors. (C) 2008 Elsevier Ltd. All rights reserved.
Citation - WoS: 65
Citation - Scopus: 67
An Electrochromic and Fluorescent Polymer Based on 1-(1
(Elsevier Science Sa, 2008) Cihaner, Atilla; Algi, Fatih; Chemical Engineering; 06. School Of Engineering; 01. Atılım University
A novel polymer was synthesized by electrochemical polymerization of 1-(1-naphthyl)-2,5-di-2-thienyl-1H-pyrrole (SNS-1-NAPH). The corresponding polymer (PSNS-1-NAPH) was characterized by cyclic voltammetry, FT-IR and UV-vis spectroscopy. The polymer has a very well-defined and reversible redox process in both organic and aqueous solutions. Furthermore, it shows stable electrochromic behavior; yellow in the neutral state, green in the intermediate state and violet in the oxidized state. PSNS-1-NAPH is soluble in common solvents. Although SNS-1-NAPH is almost nonfluorescent, its polymer is a yellow and/or green light emitter. (c) 2007 Elsevier B.V. All rights reserved.
Citation - WoS: 52
Citation - Scopus: 57
Members of Cmy Color Space: Cyan and Magenta Colored Polymers Based on Oxadiazole Acceptor Unit
(Amer Chemical Soc, 2012) Ozkut, Merve Icli; Algi, Melek Pamuk; Oztas, Zahide; Algi, Fatih; Onal, Ahmet M.; Cihaner, Atilla; Chemical Engineering; 06. School Of Engineering; 01. Atılım University
In this study, three novel oxadiazole-based polymers were synthesized and their electrochemical and optical properties were investigated. The polymers were found to have both p- and n-type doping properties accompanied by electrochromic response. Two polymer films exhibit cyan and magenta colors, which constitute two legs of CMY color spaces, in their neutral states and they are soluble in common-organic solvents. According to the color mixing theory, all colors in the visible spectrum including black color can be obtained by using these polymers with a yellow colored electrochromic polymer. Among these polymers, the polymer bearing propyledioxythiophene donor units has some superior properties like high stability (it retains 94% of its electroactivity after 2000 cycles), solubility, and high coloration efficiency (230 cm(2)/C), whereas as expected ethylenedioxythiophene containing one has the lowest band gap as 1.08 eV.
Citation - WoS: 23
Citation - Scopus: 25
A Neutral State Yellow To Navy Polymer Electrochrome With Pyrene Scaffold
(Elsevier Science Bv, 2011) Icli-Ozkut, Merve; Cihaner, Atilla; Oztas, Zahide; Algi, Fatih; Cihaner, Atilla; Cihaner, Atilla; Chemical Engineering; Chemical Engineering; 06. School Of Engineering; 01. Atılım University
A new pyrene based soluble polymer, namely poly(3,3-didecyl-6-(1-(3,3-didecyl-3,4-dihydro-2H-thieno[3,4-b][1,4] dioxepin-6-yl) pyren-6-yl)-3,4-dihydro-2H-thieno[3,4-b][1,4] dioxepine), P5, which is synthesized by both chemical and electrochemical methods, is highlighted. The polymer shows both electrochromic and fluorescent properties (the emission of yellow (545 nm) and yellowish green light (524 nm) in solid state and in THF solution, respectively). It is noteworthy that P5 has a specific optical band gap (2.2 eV) to reflect the yellow color in the neutral state. Furthermore, the optical and electrochemical features of the polymer were investigated. (C) 2011 Elsevier B. V. All rights reserved.
Citation - WoS: 94
Citation - Scopus: 95
A New Conducting Polymer Bearing 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (bodipy) Subunit: Synthesis and Characterization
(Pergamon-elsevier Science Ltd, 2008) Cihaner, Atilla; Algi, Fatih; Chemical Engineering; 06. School Of Engineering; 01. Atılım University
A new monomer system based on thiophene, pyrrole and 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene dye (SNS-BODIPY) was synthesized and its corresponding polymer (PSNS-BODIPY) was obtained via repetitive cycling or constant potential electrolysis in 0.1 M tetrabutylammonium hexafluorophosphate dissolved in dichloromethane. The PSNS-BODIPY film has very stable and well-defined reversible redox couples during p-doping process. Multi-electrochromic polymer film has a band gap of 2.9 eV with two absorption bands in its neutral state at 351 and 525 nm, attributed to the polymer backbone and BODIPY subunits, respectively. The percentage transmittance changes between both states (neutral and oxidized) were found as 12.1% for 351 nm and 17.7% for 525 nm in the visible region as well as 46.2% for 1050 nm in the near-infrared region. Beyond the robustness, the PSNS-BODIPY film has high redox stability (retaining 53.3% of its electroactivity at 351 nm after 2000 switching) with a low response time of 1.0 s. (C) 2008 Elsevier Ltd. All rights reserved.
Citation - WoS: 26
Citation - Scopus: 28
A New Electrochromic Copolymer Based on Dithienylpyrrole and Edot
(Elsevier Science Bv, 2013) Algi, Melek Pamuk; Oztas, Zahide; Tirkes, Seha; Cihaner, Atilla; Algi, Fatih; Chemical Engineering; 06. School Of Engineering; 01. Atılım University
A new compound, namely diethyl 2,5-di(thiophen-2-yl)-1H-pyrrole-3,4-dicarboxylate (1), was copolymerized with 3,4-ethylenedioxythiophene (EDOT) via electrochemical method. The copolymer exhibits multicolor electrochromic property: It is found that the copolymer, poly(1-co-EDOT), has a specific optical band gap (1.71 eV) to reflect and/or transmit reddish brown color in the neutral state, and it can be switched to reddish orange, orange, yellowish green and blue colors upon oxidation in a low switching time (1.0 s). Importantly, these colors are essential for camouflage and/or full color electrochromic device/display applications. In addition to these, the obtained copolymer has a coloration efficiency of 173 cm(2)/C at 500 nm. (C) 2013 Elsevier B.V. All rights reserved.
Citation - WoS: 30
Citation - Scopus: 31
A New Low-Voltage Polymeric Electrochromic
(Elsevier Sci Ltd, 2010) Pamuk, Melek; Tirkes, Seha; Cihaner, Atilla; Algi, Fatih; Chemical Engineering; 06. School Of Engineering; 01. Atılım University
Design, synthesis, and properties of a novel donor-acceptor-donor type low-voltage-driven green polymeric electrochrome, P1, which is based on 8-(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)-11-(2,3-dihydrothieno[3,4-b][l,4]dioxin-7-yl)acenaphtho[1,2-b]quinoxaline (1) are highlighted. It is noted that P1 has an ambipolar (n- and p-doping processes) character in 0.1 M tetrabutylammonium hexafluorophosphate/dichloromethame solution and switches to a transmissive blue state upon oxidation. Furthermore, this new polymeric electrochromic candidate exhibits high redox stability, high coloration efficiency and/or contrast ratio, high percent transmittance (%T) and low response time (1.0 s) with a band gap of 1.10 eV-1.25 eV. (C) 2009 Elsevier Ltd. All rights reserved.
Citation - WoS: 25
Citation - Scopus: 27
A New Processable and Fluorescent Polydithienylpyrrole Electrochrome With Pyrene Appendages
(Pergamon-elsevier Science Ltd, 2013) Tirkes, Seha; Mersini, Jetmire; Oztas, Zahide; Algi, Melek Pamuk; Algi, Fatih; Cihaner, Atilla; Chemical Engineering; 06. School Of Engineering; 01. Atılım University
A new hybrid compound, namely 1-(pyren-3-yl)-2,5-di(thiophen-2-yl)-1H-pyrrole (SNS-P), was polymerized via both chemical and electrochemical methods. Chemically obtained soluble polydithienylpyrrole (c-PSNS-P) bearing pyrene appendages is a homogeneous and uniform polymer with a number averaged molecular weight of 15,200 g/mol. The polymer exhibits both multi-electrochromic and fluorescent properties. Upon oxidation, the color of electrochemically obtained polymer (e-PSNS-P) changes from yellowish orange to greenish yellow and to green/blue and finally to blue. In addition, the polymer induces yellowish orange (564 nm) and bright orange emission (613 nm) in solution and solid states, respectively. (C) 2012 Elsevier Ltd. All rights reserved.
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: 24
Citation - Scopus: 25
A 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.; Chemical Engineering; 06. School Of Engineering; 01. Atılım University
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.