Yazar "Sennik, Erdem" seçeneğine göre listele

Listeleniyor 1 - 5 / 5
  • Küçük Resim Yok
    Öğe
    alpha-Thiophene end-capped styrene copolymer containing fullerene pendant moieties: Synthesis, characterization, and gas sensing properties
    (WILEY, 2016) Sennik, Erdem; Sennik, Busra; Alev, Onur; Kilinc, Necmettin; Yilmaz, Faruk; Ozturk, Zafer Ziya
    We report the synthesis, characterization, and gas sensing properties of a styrene copolymer bearing -thiophene end group and fullerene (C-60) pendant moieties P(S-co-CMS-C-60). First, the copolymer of styrene (S) and chloromethylstyrene (CMS) monomers was prepared in bulk via a bimolecular nitroxide-mediated radical polymerization (NMP) technique using benzoyl peroxide (BPO) as the radical initiator and nitroxy-functional thiophene compound (Thi-TEMPO) as the co-radical and this gave -thiophene end-capped copolymer P(S-co-CMS). The chloromethylstyrene units of P(S-co-CMS) allowed further side-chain functionalization onto P(S-co-CMS). The obtained P(S-co-CMS) was then reacted with sodium azide (NaN3) and this led to the copolymer with pendant azide groups, P(S-co-CMS-N-3), and then grafted with electron-acceptor C-60 via the reaction between N-3 and C-60. The final product was characterized by using NMR, FTIR, and UV-vis methods. Electrical characterization of P(S-co-CMS-C-60) thin film was also investigated at between 30 and 100 degrees C as the ramps of 10 degrees C. Temperature dependent electrical characterization results showed that P(S-co-CMS-C-60) thin film behaves like a semiconductor. Furthermore, P(S-co-CMS-C-60) was employed as the sensing layer to investigate triethylamine (TEA), hydrogen (H-2), acetone, and ethanol sensing properties at 100 degrees C. The results revealed that P(S-co-CMS-C-60) thin film has a sensing ability to H-2. (c) 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43641.
  • Küçük Resim Yok
    Öğe
    Electrical and VOC sensing properties of anatase and rutile TiO2 nanotubes
    (ELSEVIER SCIENCE SA, 2014) Sennik, Erdem; Kilinc, Necmettin; Ozturk, Zafer Ziya
    The dc electrical and volatile organic compound (VOC) sensing properties of TiO2 nanotubes in both anatase and rutile phases were investigated. TiO2 nanotube arrays were obtained in aqueous HF (0.5 wt.%) electrolytes by anodizing of Ti thin films that deposited on quartz substrates using thermal evaporation. Anodization was performed at 10 V in aqueous HF at 0 degrees C. Then the fabricated TiO2 nanotubes were annealed at 300 degrees C and at 700 degrees C under dry air for 5 h to obtain anatase and rutile phases, respectively. The TiO2 nanotubes were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) as structural, and UV-vis spectrophotometer as optical. The current voltage characteristics of the nanotubes under dry air flow revealed that the conductivity of the sample with anatase phase was higher than that of the sample with rutile phase. The VOCs sensing properties of the nanotubes were investigated at 200 degrees C. It was found that the sensor response of anatase was higher than that of rutile for almost all VOC gases. On the other hand, the sensitivities of two sensors are the highest for isopropyl alcohol. (C) 2014 Elsevier B.V. All rights reserved.
  • Küçük Resim Yok
    Öğe
    Gas sensor application of hydrothermally growth TiO2 nanorods
    (ELSEVIER SCIENCE BV, 2015) Alev, Onur; Sennik, Erdem; Kilinc, Necmettin; Ozturk, Zafer Ziya; Urban, G; Wollenstein, J; Kieninger, J
    This study focuses on TiO2 nanorod-based gas sensor. TiO2 nanorods were fabricated on fluorine doped tin oxide (FTO) substrate by hydrothermal method. The hydrothermal solution was prepared with titanium but -oxide, hydrochloric acid and deionized water (volume ratio 1:30:30). The morphologies and structure of the samples were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). Highly ordered and homogenous TiO2 nanorods obtained has a diameter of ca. 100 nm. Gas sensing properties of these structures were investigated against VOCs and different concentrations of H-2 at 200 degrees C. Sensor response was 200 (%) for 1000 ppm H-2. Among measured VOCs, TiO2 nanorods are only sensitive to isopropanol at 200 degrees C. (C) 2015 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-ric-nd/4.0/) Peer-review under responsibility of the organizing committee of EUROSENSORS
  • Küçük Resim Yok
    Öğe
    Sputtered platinum thin films for resistive hydrogen sensor application
    (ELSEVIER SCIENCE BV, 2016) Sennik, Erdem; Urdem, Seyma; Erkovan, Mustafa; Kilinc, Necmettin
    This work presents hydrogen (H-2) sensing properties of platinum (Pt) thin film deposited on glass substrate by sputter technique. The Pt thin films with different thickness prepared using RF sputtering method were characterized by the XRD, SEM and XPS techniques. Temperature dependent resistances and the gas measurements of the Pt thin films were investigated under a dry air flow at a temperature range from 30 degrees C to 200 degrees C. The H-2 sensing properties of Pt thin film sensors were also examined in the concentration range of 0.1-1% H-2. The results revealed that the Pt thin film with 2 nm thickness exhibited the best sensing performance to H-2 at 30 degrees C under dry air flow. (C) 2016 Elsevier B.V. All rights reserved.
  • Küçük Resim Yok
    Öğe
    The effect of Pd on the H-2 and VOC sensing properties of TiO2 nanorods
    (ELSEVIER SCIENCE SA, 2016) Sennik, Erdem; Alev, Onur; Ozturk, Zafer Ziya
    This work presents highly sensitive TiO2 nanorods modified with palladium to investigate the sensing properties of H-2 and volatile organic compound (VOC) gases. TiO2 nanorods were synthesized in a mixed solution containing 1 ml of titanium n-butoxide (TnBT) by the hydrothermal method. Pd on the surface of the TiO2 nanorods was decorated by heat treatment. The samples were characterized by the X-ray diffraction (XRD), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) techniques. The electrical properties of the TiO2 and Pd loaded TiO2 nanorods were investigated under a dry air flow at a temperature range from 30 degrees C to 200 degrees C. The H-2 sensing properties of the TiO2 nanorods decorated with Pd were investigated in the concentration range of 500-2000 ppm at 200 degrees C. Moreover, the effect of Pd on the VOC gas sensing properties of the TiO2 nanorods was examined at 200 degrees C. The results revealed that the nanorods modified with palladium exhibited excellent sensing performance to H-2 at 30 degrees C, and also had the appropriate sensor behavior at 200 degrees C with clear response-recovery, good stability, and reproducibility. The maximum VOC response was obtained for ethanol. (c) 2016 Published by Elsevier B.V.