Browsing by Subject "Polycyclic aromatic hydrocarbons"

Now showing 1 - 8 of 8
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    Determination of polycyclic aromatic hydrocarbons in edible oils and barbecued food by HPLC/UV-Vis detection
    (2012) Dost K.; Deli C.
    Determination of nine polycyclic aromatic hydrocarbons in corn, sunflower, olive oils and barbecued meat and fish by HPLC/UV-Vis method is described. The extraction procedure included a saponification, liquid-liquid extraction and finally purification of PAHs through a house-made silica-alumina column. Chromatographic determination was based on separation of PAHs on ODS column and measurement at 254 nm. All polycyclic aromatic hydrocarbons were separated and analyzed in 12 min on reversed phase ODS column with acetonitrile/water mobile phase at 1.5 mL min -1 flow rate. The detection limits of nine polycyclic aromatic hydrocarbons ranged from 0.26 to 1.15 μg L -1 at a signal/noise ratio of 3. The linearity of the method was between 0.9951 and 0.9996. Oil samples contain different PAHs ranging from 0.44 to 98.92 μg L -1. Barbecuing process increased the concentration (in the range of 2- to 8-fold) and caused the formation of PAHs in food samples. © 2011 Elsevier Ltd. All rights reserved.
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    Iron(III) selective fluorescence probe based on perylene tetracarboxylic diimide
    (Maik Nauka Publishing / Springer SBM, 2014) Tirtom V.N.; Çelik-Erbaş S.; Birel O.; Xue C.
    Responses of organic fluorophore, perylenediimide derivative N,N'-di[3-[2-(3-thienyl)ethyl]phenyl]perylene-3,4,9,10-bis-(dicarboxyimide) (PDI1) was investigated in polymer matrix of polyvinyl chloride (PVC) by emission spectrometry. Its response to Fe(III) ions was evaluated in terms of the effect of pH. The properties of time dependent response, reversibility, limit of detection, linear concentration range for the metal ion and repeatability characteristics of the sensing element also have been studied. The offered sensor exhibited remarkable fluorescence intensity quenching at pH 6.0 in the concentration range of 1 × 10-6 to 2.5 × 10 -3 M Fe(III) ions. The reproducibility of the sensor membrane was investigated by alternately changing the solution between 1 × 10 -4 M Fe(III) in Na2HPO4 (4 × 10 -2 M) and NaH2PO4 buffer (2 × 10 -3 M). © 2014 Pleiades Publishing, Ltd.
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    Functionalized bay-substituted perylene diimide additives for inverted organic photovoltaic devices based on P3HT/PCBM
    (National Institute of Optoelectronics, 2015) Dinçalp H.; Çmen O.; Murat Saltan G.; Çl S.
    The photovoltaic performances of inverted organic solar cells including P3HT:PCBM active layer with perylene diimides (PDIs) substituted with different subunits at bay positions of perylene ring were investigated. The improvement of photoluminescence intensity for P3HT:PCBM blend was achieved by the increase of PDI1 additive amount from 6.6 to 10 wt%. In P3HT:PDI1:PCBM ternary blend, preliminary results obtained from cell measurements indicated that PDI1 dopant has improved the cell efficiency by 38% compared to the control cell. Carrier mobility studies revealed that electron or hole mobility capacities of the perylene additives in ternary blends gave a more detailed explanation for efficiencies both binary and ternary systems.
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    Spectroscopic studies on 9H-carbazole-9-(4-phenyl) boronic acid pinacol ester by DFT method
    (Elsevier B.V., 2016) Sas E.B.; Kurt M.; Can M.; Horzum N.; Atac A.
    9H-Carbazole-9-(4-phenyl) boronic acid pinacol ester (9-CPBAPE) molecule was investigated by FT-IR, Raman, UV-vis, 1H and 13C NMR spectra. FT-IR, FT-Raman and dispersive Raman spectra were recorded in the solid phase. 1H, 13C NMR and UV-vis spectra were recorded in dimethyl sulfoxide (DMSO) solution. The results of theoretical calculations for the spectra of the title molecule were compared with the experimental spectra. The highest occupied molecular orbital (HOMO) the lowest unoccupied molecular orbital (LUMO) and molecular electrostatic potential (MEP) analyses were performed. The theoretical calculations for the molecular structure and spectroscopic studies were performed with DFT (B3LYP) and 6-311G (d,p) basis set calculations using the Gaussian 09 program. The total (TDOS), partial (PDOS) density of state and overlap population density of state (OPDOS) diagrams analyses were performed using GaussSum 2.2 program. © 2016 Elsevier B.V. All rights reserved.
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    Surface modification of CdSeS nanocrystals for polymer hybrid solar cells
    (Royal Society of Chemistry, 2016) Erdogan A.; Karakaya C.; Gonce M.K.; Buyukcelebi S.; Yenel E.; Kara K.; Ozcivan A.N.; Can M.; Kus M.; Demic S.
    We report the synthesis of fluorene-carbazole derivatives as capping agents for CdSeS nanocrystals and present their performance in polymer hybrid solar cells. CdSeS nanocrystals and different ligands consisting of fluorene and carbazole units were synthesized and characterized. Both oleic acid and pyridine capped CdSeS nanocrystals were used as reference materials in polymer hybrid solar cells. We observed that our synthesized materials show better efficiencies depending on their structures. In comparison with the reference cells consisting of pyridine capped CdSeS nanocrystals, ligand capped CdSeS shows better efficiency due to electron withdrawing and accepting groups in its structure. The reason behind the superiority of our ligands compared to the reference pyridine is the donor and/or acceptor based compatibility of the combined structures and effective surface modification as well. © 2016 The Royal Society of Chemistry.
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    Synthesis and determination of fluorescence properties of new soluble diketopyrrolopyrrole type photosensitizers
    (Elsevier B.V., 2019) türkçen S.; dinçalp H.; murat saltan G.
    Four organic small molecules bearing phenyl diketopyrrolopyrrole (DPP) unit as the main acceptor group and indole as the main thermal group with soluble units, coded as DPP3(a-b) and DPP4(a-b), were synthesized and their optical/electrochemical properties were investigated. Intense visible absorption bands around 480 nm were assigned to the DPP main core, as well as bands around 600 nm were attributed to the formation of charge-transfer complex between the electron-rich indole units and electron-withdrawing DPP core in chloroform solution. All of the compounds were found to be fluorescent in solution and on thin films with emission wavelengths between 500 and 700 nm. The fluorescence decay kinetic measurements of these dyes were also studied. The synthesized compounds have electrochemical energy band gaps from 2.15 to 2.28 eV. Then, the potential usage of the final products in bulk heterojunction solar cells (BHJ-OSCs) were evaluated. © 2019 Elsevier B.V.
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    Highly conjugated isoindigo and quinoxaline dyes as sunlight photosensitizers for onium salt-photoinitiated cationic polymerization of epoxy resins
    (John Wiley and Sons Ltd, 2022) Ercan B.T.; Gultekin S.S.; Yesil T.; Dincalp H.; Koyuncu S.; Yagci Y.; Zafer C.
    In this study, photoinitiated cationic polymerization of epoxy resins by photoinduced electron transfer reactions using four new chromophoric dyes, namely (3E)-1,1′-bis(2-ethylhexyl)-6,6′-dipyren-1-yl-3,3′-biindole-2,2′(1H,1′H)-dione (ISOIV), (3′E)-1,1′′′-diethyl-1′,1′′-bis(2-ethylhexyl)-1H,1′′′H-5,6′:3′,3′′:6′′,5′′′-quaterindole-2′,2′′(1′H,1′′H)-dione (ISOV), (3E)-6,6′-bis(9-ethyl-9H-carbazole-3-yl)-1-[(2R)-2-ethylhexyl]-1′-[(2S)-2-ethylhexyl]-3,3′-biindole-2,2′(1H,1′H)-dione (ISOVIII) and 3,3′-(6-bromokinoksalin-2,3-diyl)bis(9-ethyl-9H-carbazole) (TPDC6), and diphenyliodonium hexafluorophosphate (Ph2I+PF6−; DPI) under sunlight is reported. Upon irradiation, photoexcited dye forms an exciplex with DPI. Electron transfer reactions within the exciplex result in the formation of ionic species capable of initiating ring-opening polymerization of an epoxy resin. It is shown that among the investigated dyes, ISOVIII and TPDC6 exhibited higher initiation efficiency in accordance with their stronger electron-donating nature due to the presence of carbazole groups. © 2021 Society of Industrial Chemistry. © 2021 Society of Industrial Chemistry.
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    Enhancing solar thermal storage properties of azobenzenes with conductive polymer: Electropolymerization of carbazole containing photoactive cyanoazobenzene derivative
    (Elsevier Ltd, 2023) Sert S.; Ayranci R.; Çılgı G.K.; Ak M.
    Solar thermal fuels (STFs) have recently drawn attention as a promising strategy for utilization of solar energy that is a clean and renewable source. Especially solid state solar thermal fuels have high potential to be used in thermal applications. However, up to date, it is seen that the solar thermal storage capacity in the polymeric state is lower than in the corresponding monomers. Herein, for the first time, photoactive azobenzene and electroactive carbazole containing monomer (Cz-AzoCN) was designed and thermal storage properties of the monomer and the corresponding polymer obtained by electropolymerization were investigated. This study showed that polycarbazoles containing azobenzene pendant groups can be an effective thermal storage platform due to their easy functionality, high light absorption and rigid conjugated chain structure resembling the structure of rigid templates decorated with closely packed photochromic units. Additionally, electropolymerization is an easy and rapid method for polymer synthesis, producing polymer in the form of film that is ready for irradiation. The gravimetric energy storage density of p(Cz-AzoCN) was calculated as 145.12 j g−1 which was 128 % higher than that of monomer. This is due to boosted light harvesting of conjugated polycarbazole backbone as an organic photosensitizer that providing effective solar thermal storage. © 2023 Elsevier Ltd