Kayı, Hakan

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Hakan, Kayı
Kayi,H.
H.,Kayı
H.,Kayi
Kayı,H.
Hakan, Kayi
K., Hakan
K.,Hakan
Kayi, Hakan
H., Kayi
Kayı, Hakan
Kayi, H.
Job Title
Doktor Öğretim Üyesi
Email Address
hakan.kayi@atilim.edu.tr
Main Affiliation
Chemical Engineering
Status
Former Staff
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Scholarly Output

30

Articles

21

Citation Count

101

Supervised Theses

8

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2014 - 20164
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Subject: DFT

Scholarly Output Search Results

Now showing 1 - 4 of 4
  • Thumbnail Image
    Article
    Citation - WoS: 10
    Citation - Scopus: 9
    A Computational Study on 4,7-Di(furan Monomer and Its Oligomers
    (Springer, 2014) Kayi, Hakan; Kayı, Hakan; Kayı, Hakan; Chemical Engineering; Chemical Engineering
    The energy gap, Eg, between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) energy levels that determines the electronic and optical properties of 4,7-di(furan-2yl)benzo[c][1,2,5]thiadiazole (FSF) polymer is calculated by performing quantum chemical calculations. First, we theoretically investigated the most stable conformers of FSF monomer and its corresponding oligomers at the B3LYP/6-31G(d) and B3LYP/LANL2DZ levels of theory. We reveal the theoretical molecular structure of this very recently synthesized novel monomer and its oligomers for the first time in the literature. Our results from the B3LYP/6-31G(d) calculations indicated that FSF polymer has a low HOMO-LUMO gap of 1.55 eV to be in good agreement with the experiments. Experimental design and synthesis of novel conjugated polymers require time-consuming and expensive procedures. The findings from this study are promising for the use of computational methods in the design of the novel conjugated polymers, and help to narrow the materials to be used in design and synthesis of conjugated polymers with desired properties.
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    Article
    Citation - WoS: 8
    Citation - Scopus: 9
    A Theoretical Investigation of 4,7-Di(furan Donor-Acceptor Type Conjugated Polymer
    (Elsevier, 2015) Kayi, Hakan; Elkamel, Ali; Chemical Engineering
    Quantum chemical calculations are performed using density functional theory (DFT) to investigate the HOMO-LUMO energy gap of the 4,7-di(furan-2-yl)benzo[c][1,2,5]selenadiazole-based (FSeF) donor-acceptor type conjugated polymer which ascertains the optoelectronic properties and plays a crucial role, especially in polymeric solar cell applications. In this paper, the most stable conformers of the FSeF monomer and its corresponding oligomers are investigated at the B3LYP/Def2TZV and B3LYP/LANL2DZ levels of theory, and their molecular structures are revealed. The band gap of the polymer is determined by linear-fitting and extrapolation of the DFT data. This gap is found to be 1.44 eV and 1.45 eV by the B3LYP/Def2TZV, and B3LYP/LANL2DZ with PCM calculations, respectively. Our theoretical findings related to the band gap of the FSeF polymer (PFSeF) are in good agreement with other experimental studies in the literature and, hence, the theoretical methods used in this study are promising for the design of similar donor-acceptor type novel conjugated polymers. (C) 2014 Elsevier B.V. All rights reserved.
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    Article
    Citation - WoS: 2
    Citation - Scopus: 3
    Experimental and Theoretical Investigation of the Reaction Between Co2 and Carbon Dioxide Binding Organic Liquids
    (Tubitak Scientific & Technological Research Council Turkey, 2016) Tankal, Hilal; Yuksel Orhan, Ozge; Alper, Erdogan; Ozdogan, Telhat; Kayi, Hakan; Chemical Engineering
    The reaction kinetics of CO2 absorption into new carbon dioxide binding organic liquids (CO(2)BOLs) was comprehensively studied to evaluate their potential for CO2 removal. A stopped-flow apparatus with conductivity detection was used to determine the CO2 absorption kinetics of novel CO(2)BOLs composed of DBN (1,5-diazabicyclo[4.3.0]non-5-ene)/1-propanol and TBD (1,5,7-triazabicyclo[4.4.0]dec-5-ene)/1-butanol. A modified termolecular reaction mechanism for the reaction of CO2 with CO(2)BOLs was used to calculate the observed pseudo-first order rate constant k(0) (s(-1)) and second-order reaction rate constant k(2) (m(3)/kmol.s). Experiments were performed by varying organic base (DBN or TBD) weight percentage in alcohol medium for a temperature range of 288-308 K. It was found that k(0) increased with increasing amine concentration and temperature. By comparing using two different CO2BOL systems, it was observed that the TBD/1-butanol system has faster reaction kinetics than the DBN/1-propanol system. Finally, experimental and theoretical activation energies of these CO2BOL systems were obtained and compared. Quantum chemical calculations using spin restricted B3LYP and MP2 methods were utilized to reveal the structural and energetic details of the single-step termolecular reaction mechanism.
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    Article
    Citation - WoS: 15
    Citation - Scopus: 17
    Kinetics of Co2 Capture by Carbon Dioxide Binding Organic Liquids: Experimental and Molecular Modelling Studies
    (Elsevier Sci Ltd, 2016) Orhan, Ozge Yuksel; Tankal, Hilal; Kayi, Hakan; Alper, Erdogan; Chemical Engineering
    In the scope of this work, new carbon dioxide binding organic liquids (CO(2)BOLs) were developed and kinetic parameters in terms of pseudo first-order rate constants for homogenous reaction between CO2 and CO(2)BOLs in 1-hexanol were obtained by using stopped-flow method with conductivity detection. As an amidine DBN (1,5-diazabicyclo[4.3.0]non-5-ene) and as a guanidine TBD (1,5,7-triazabicyclo[4.4.0]dec-5-ene) and BTMG (2-tert-butyl-1,1,3,3-tetramethylguanidine) were investigated. Experiments were performed by varying organic base (amidine or guanidine) weight percentage in 1-hexanol medium for a temperature range of 288-308 K. A modified termolecular reaction mechanism was used to analyse the experimental kinetic data. In addition, quantum chemical calculations by using B3LYP, MP2 and CCSD methods were performed to reveal the structural and energetic details of the single step termolecular reaction mechanism. Experimental and theoretical activation energies for these novel carbon dioxide capturing organic liquids were also unveiled. (C) 2016 Elsevier Ltd. All rights reserved.