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1

Thermal and Electrical Properties of Carbon Nanotube Based Materials

100%

Yuca N., Karatepe N., Yakuphanoğlu F., Gürsel Y.

Acta Physica Polonica A

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2013

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vol. 123

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issue 2

352-354

EN

In this study, carbon nanotubes were synthesized at temperatures of 500C and 800C by the fluidized-bed chemical vapor deposition method. The synthesized material was purified by using 3 M HCl at 75°C, 15 h. After synthesis and purification, the polyaniline-doped H_3BO_3 and BF_3 and composites were prepared by coagulation method. Transmission electron microscope and Fourier transform infrared spectroscopy were used to characterize the carbon nanotubes and their composites. Thermal stabilities were measured by thermogravimetry and differential scanning calorimetry instruments. The thermogravimetry and derivative thermogravimetry curves indicated that the thermal stability of polyaniline-doped H_3BO_3 and BF_3 increased with carbon nanotube doping. The electrical properties of carbon nanotubes and their composites were also determined. The obtained electrical conductivity values of the nanocomposites including the polyaniline-doped H_3BO_3 and BF_3 were typical for organic semiconductor materials. It can be evaluated that the electrical properties of the polyaniline based polymers can be controlled by carbon nanotube doping.

2

Influence of Temperature and Impregnation Ratio of H_3PO_4 on the Production of Activated Carbon from Hazelnut Shell

100%

Örkün Y., Karatepe N., Yavuz R.

Acta Physica Polonica A

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2012

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vol. 121

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issue 1

277-280

EN

Hazelnut shell was used as a precursor in the production of activated carbon by chemical activation with H_3PO_4 since there is a huge volume of such a solid waste resulting from the hazelnut production in eastern Black Sea region of Turkey. Effects of final activation temperature, time and H_3PO_4 concentration used in the impregnation stage on the porous development were investigated. Activation at low temperature represented that micropores were developed first and then mesoporosity developed, enhanced up to 400C and then started to decrease due to possible shrinking of pores. The optimum temperature for hazelnut shell was found to be around 400C on the basis of total pore volume and the Brunauer-Emmett-Teller surface area. It was clearly demonstrated that H_3PO_4 concentration used in the impregnation stage was not only effective for development of surface area and pore volumes but also an effective tool for tailoring the pore structure and size distribution.

3

MoO_{x} Doped Single-Walled Carbon Nanotube Films as Hole Transport Layer for Organic Solar Cells

76%

Çolak F., Dalkılıç Z., Tabatabaei A., Atlıbatur R., Çolak Ü., Arıc E., Karatepe N.

Acta Physica Polonica A

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2017

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vol. 131

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issue 3

474-476

EN

Metal-oxide thin films have recently become good candidates for the hole transport layer material, for solving the stability problem in organic photovoltaic devices. Metal oxide semiconductors (MoO_{x}, WO₃, V₂O₅) are very promising because of their suitable optoelectronic properties, ambient stability, high work function, and solution processability. Intrinsic n-type behavior of molybdenum oxide (MoO_{x}) is found to enhance p-type doping effect on single-walled carbon nanotubes. In this study, the effect of using MoO_{x} doped single-walled carbon nanotube films as hole transport layer in organic solar cells was investigated. Thin films and organic solar cells were characterized using scanning electron microscopy, atomic force microscopy, UV-NIR absorption spectroscopy and device current-voltage measurements.

4

Kinetic and Thermodynamic Behavior of Selenium on Modified Bentonite and Activated Carbon using Radiotracer Technique

64%

Tuğrul B., Erentürk S., Haciyakupoğlu S., Karatepe N., Altinsoy N., Baydoğan N., Baytaş F., Büyük B., Demir E., Gedik S.

Acta Physica Polonica A

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2015

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vol. 128

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issue 2B

B-180-B-181

EN

This study was aimed to determine kinetic and thermodynamic behaviors of selenium on modified bentonite and activated carbon. Thermodynamic parameters such as enthalpy ΔH, free energy change ΔG and entropy change ΔS of selenium adsorption suggested that the adsorption of Se(IV) on activated carbon and organic-inorganic modified bentonite was exothermic and endothermic process, respectively. The experimental data fitted very well the pseudo-second-order kinetic model for both adsorbents.

5

Investigation for Remediation of Selenium Aqueous Environment with Using Organic Pillared Bentonite by Radiotracer Technique

52%

Tugrul A., Haciyakupoglu S., Erenturk S., Karatepe N., Baytas F., Baydogan N., Altinsoy N., Buyuk B., Orucoglu E., Demir E., Camtakan Z., Okka M.

Acta Physica Polonica A

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2015

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vol. 127

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issue 4

1186-1188

EN

In this study remediation of selenium ions from aqueous solutions was investigated using organic pillared bentonite as an adsorbent. Organic pillared bentonite was produced from Resadiye (Tokat, Turkey) bentonite using hexadecylpyridinium chloride and aluminum polyoxy-cations. All the experiments were carried out by tracing with selenium radioisotope. For the production of the radioactive selenium radioisotope, selenium dioxide was irradiated in the central thimble of ITU TRIGA Mark II Training and Research Reactor at Energy Institute of Istanbul Technical University. Radioactivity measurements carried out by the gamma-ray spectroscopy system were used to determine of selenium isotope. The relative importance of test parameters like concentration of adsorbate, pH of the solution and contact time on adsorption performance of organic pillared bentonite for selenium ion was studied. Evaluation of experiments for different parameters showed possibility of remediation of selenium from aqueous media by using organic pillared bentonite.

Refine search results

Thermal and Electrical Properties of Carbon Nanotube Based Materials

Influence of Temperature and Impregnation Ratio of H_3PO_4 on the Production of Activated Carbon from Hazelnut Shell

MoO_{x} Doped Single-Walled Carbon Nanotube Films as Hole Transport Layer for Organic Solar Cells

Kinetic and Thermodynamic Behavior of Selenium on Modified Bentonite and Activated Carbon using Radiotracer Technique

Investigation for Remediation of Selenium Aqueous Environment with Using Organic Pillared Bentonite by Radiotracer Technique