Physics / Fizik
Permanent URI for this collectionhttps://hdl.handle.net/11147/6
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Article Citation - WoS: 42Citation - Scopus: 42Investigation of Humidity Sensing Properties of Zns Nanowires Synthesized by Vapor Liquid Solid (vls) Technique(Elsevier Ltd., 2011) Üzar, Neslihan; Okur, Salih; Arıkan, M. ÇetinZinc sulfide (ZnS) nanostructures were synthesized by vapor-liquid-solid (VLS) method which is based on thermal evaporation. The morphology, chemical composition and crystal structure of ZnS nanostructures were characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) analyses. The results of these studies revealed that wurtzite ZnS nanowires with diameters in range of 50-400 nm are obtained. In order to investigate the humidity sensing capability, quartz crystal microbalance (QCM) and electrical resistance measurement techniques were carried out at different relative humidity (RH) conditions between 33% and 100% RH at room temperature. QCM results show that the oscillating frequency of ZnS nanowires loaded on QCM crystal decreases in range of 33-84% RH, but increases at 90% and 100% RH. The sensitivity of ZnS nanowires-based sensor (R air/RRH) increases over 1000 times from 33% to 100% RH. These experimental results show that ZnS nanowires have a great potential for humidity sensing applications at room temperature.Article Citation - WoS: 34Citation - Scopus: 37Humidity Adsorption Kinetics of Water Soluble Calix[4]arene Derivatives Measured Using Qcm Technique(Elsevier Ltd., 2010) Okur, Salih; Kuş, Mahmut; Özel, Faruk; Yılmaz, MustafaWe report on the optimization and characterization of water soluble calix[4]arene derivative as a humidity sensor based on quartz crystal microbalance technique. The moisture adsorption and desorption kinetics of calix[4]arene were investigated. The Langmuir model was used to determine the kinetic parameters such as adsorption, desorption rates and Gibbs free energy between relative humidity between 29% and 78%. Reproducible experimental results were obtained showing that water soluble calix[4]arene films have a great potential for humidity sensing applications at room temperature operations. © 2009 Elsevier B.V. All rights reserved.Article Citation - WoS: 138Citation - Scopus: 146Humidity Sensing Properties of Zno Nanoparticles Synthesized by Sol-Gel Process(Elsevier Ltd., 2010) Erol, Ayşe; Okur, Salih; Comba, B.; Mermer, Ömer; Arıkan, M. Ç.ZnO nanoparticles have been synthesized by the sol-gel method with approximately 10 nm diameter and the humidity adsorption and desorption kinetics of ZnO nanoparticles were investigated by quartz crystal microbalance (QCM) technique. The morphology and crystal structure of the ZnO nanoparticles have been characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively. The roughness of the surface has been investigated using atomic force microscope (AFM). The dynamic Langmuir adsorption model was used to determine the kinetic parameters such as adsorption and desorption rates and Gibbs free energy under relative humidity between 45% and 88%. The relative sensitivity of the ZnO nanoparticles-based humidity sensor was determined by electrical resistance measurements. Our reproducible experimental results show that ZnO nanoparticles have a great potential for humidity sensing applications at room temperature operations. © 2009 Elsevier B.V. All rights reserved.Article Citation - WoS: 36Citation - Scopus: 30Humidity Adsorption Kinetics of Calix[4]arene Derivatives Measured Using Qcm Technique(Elsevier Ltd., 2010) Okur, Salih; Kuş, Mahmut; Özel, Faruk; Aybek, Vildan; Yılmaz, MustafaThis study focuses on the characterization of sulphonated calix[4]arene derivative films coated on a quartz substrate with a thickness of 40 nm by spin coating method for humidity detection. The humidity adsorption kinetics of the sulphonated calix[4]arene films was investigated by quartz crystal microbalance (QCM) technique. The Langmuir model was used to determine the adsorption rates and Gibbs free energy for various relative humidities between 11% and 97%. Our reproducible experimental results show that suphonated calix[4]arene films have a great potential for humidity sensing applications at room temperature operations. © 2009 Elsevier B.V. All rights reserved.Article Citation - WoS: 36Citation - Scopus: 37Humidity Sensing Properties of Novel Ruthenium Polypyridyl Complex(Elsevier Ltd., 2010) Ocakoğlu, Kasım; Okur, SalihWe report the characterization of novel ruthenium polypyridyl complex (Ru-PC) based sensor film with a thickness of 50 nm coated on a quartz substrate using a spin coating method for humidity detection. The resulting complex [Ru(L1)2(L2)] was synthesized in a one-pot reaction starting from [RuCl2(p-cymene)]2, where the ligands (L1 = 4,7-diphenyl-1,10-phenanthroline-disulfonic acid disodium salt and L2 = 4,4′-dicarboxy-2,2′-bipyridine) were characterized by NMR, mass spectrometry (MALDI), elemental analysis and UV-vis spectroscopy. The humidity adsorption and desorption kinetics of the ruthenium complex were investigated using the Quartz Crystal Microbalance (QCM) technique. The Langmuir model was used to determine adsorption and desorption rates and Gibbs free energy over the 11-97% relative humidity range. Our experimental results show that Ru-PC films have a great potential for humidity sensing applications at standard conditions (i.e. room temperature). © 2010 Elsevier B.V. All rights reserved.