Chemistry / Kimya
Permanent URI for this collectionhttps://hdl.handle.net/11147/4072
Browse
4 results
Search Results
Article Citation - WoS: 169Citation - Scopus: 177Thin Film Microextraction: Towards Faster and More Sensitive Microextraction(Elsevier Ltd., 2019) Ölçer, Yekta Arya; Eroğlu, Ahmet Emin; Tascon, Marcos; Eroğlu, Ahmet Emin; Boyacı, Ezel; 04.01. Department of Chemistry; 04. Faculty of Science; 01. Izmir Institute of TechnologyThin film microextraction (TFME) is an analytical tool that has been proven to be suitable for integrated sampling and sample preparation of a wide variety of routine and on-site applications. Compared to the traditional microextraction techniques, the most important advantage of TFME is its enhanced sensitivity due to the relatively larger extractive phase spread over a larger surface area. The technique, in this way, facilitates fast extraction kinetics and high extractive capacity. Moreover, TFME offers high versatility for device development over classical SPME technologies due to the plethora of available extractive phases, coating methods and geometry options. The goal of this review is to provide a comprehensive summary of the contemporary advances in this exciting field covering novel extractive phases, technological and methodological developments, and relevant cutting-edge applications. Finally, a critical discussion of the future trends on TFME is also presented. (C) 2019 Elsevier B.V. All rights reserved.Article Citation - WoS: 44Citation - Scopus: 53Smart Phone Assisted Detection and Quantification of Cyanide in Drinking Water by Paper Based Sensing Platform(Elsevier Ltd., 2017) İncel, Anıl; Akın, Osman; Demir, Mustafa Muammer; Yıldız, Ümit Hakan; Demir, Mustafa Muammer; Çağır, Ali; Yıldız, Ümit Hakan; 04.01. Department of Chemistry; 03.09. Department of Materials Science and Engineering; 03. Faculty of Engineering; 04. Faculty of Science; 01. Izmir Institute of TechnologyAn organometallic dye, europium tetrakis dibenzoylmethide triethylammonium (EuD4TEA) and gold nanoparticles (Au NPs) impregnated paper based sensor platform have been utilized for development of fluorescence turn-on cyanide assay in aqueous media. The ordinary filter paper with 6 μ m pore size were employed as solid support that facilitates impregnation of EuD4TEA and gold nanoparticles and provides durability. Detection mechanism relying on two processes (i) dissolution of gold nanoparticles causing fluorescence recovery and (ii) ligand exchange of triethyl amine with CN group stimulating cyanide specific fluorescence enhancement. The paper platform exhibit naked eye distinguishable color transition upon CN− addition from 10−2 to 10−12 M. To standardize the methodology a homemade image processing algorithm has been developed that enabling calibration of color change and quantify CN− concentration. The described algorithm is applicable to Android smart phones and facilitate transforming these devices into a quantitative cyanide detector. The overall methodology provides instrument free cyanide detection and therefore rapid control of water quality and safety at off-field conditions.Article Citation - WoS: 69Citation - Scopus: 82Development and Characterization of Tubular Composite Ceramic Membranes Using Natural Alumino-Silicates for Microfiltration Applications(Elsevier Ltd., 2015) Ghouil, Boudjemaa; Demir, Mustafa Muammer; Harabi, Abdelhamid; Bouzerara, Ferhat; Boudaira, Boukhemis; Guechi, Abdelkrim; Demir, Mustafa Muammer; Figoli, Alberto; 03.09. Department of Materials Science and Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyAbstract The preparation and characterization of porous tubular ceramic composite microfiltration membranes, using kaolins and calcium carbonates, were reported. The porous gehlenite (2CaO·Al2O3·SiO2) and anorthite (CaO·Al2O3·2SiO2) based ceramics were obtained by a solid state reaction. A ceramic support, sintered at 1250 C, within an average pore size of about 8 μm, a porosity of about 47% and a compression strength around 40 MPa, was prepared. The microfiltration active top layer was added on the support by a slip casting from clay powder suspensions. The novel microfiltration membrane layer has a thickness of 40 μm and an APS value of about 0.2 μm. This average pore size value was improved and considerably lower than those reported in the literature (0.5 μm). The performance of the novel microfiltration ceramic membrane was determined for evaluating both the water permeability and rejection. This proved the potentiality of the membrane produced in the microfiltration field. Moreover, the good adhesion, between the support and the active microfiltration layer membranes, was also proved. A correlation between microstructures of used powders and physicochemical properties was discussed. Finally, the origin of the unique two powder order membrane depositions was also proposed.Article Citation - WoS: 74Humidity Sensing Properties of Zno-Based Fibers by Electrospinning(Elsevier Ltd., 2011) Horzum Polat, Nesrin; Taşçıoğlu, Didem; Okur, Salih; Demir, Mustafa Muammer; Demir, Mustafa Muammer; 04.05. Department of Pyhsics; 03.09. Department of Materials Science and Engineering; 03. Faculty of Engineering; 04. Faculty of Science; 01. Izmir Institute of TechnologyZinc oxide (ZnO) based fibers with a diameter of 80-100 nm were prepared by electrospinning. Polyvinyl alcohol (PVA) and zinc acetate dihydrate were dissolved in water and the polymer/salt solution was electrospun at 2.5 kV cm-1. The resulting electrospun fibers were subjected to calcination at 500 °C for 2 h to obtain ZnO-based fibers. Humidity sensing properties of the fiber mats were investigated by quartz crystal microbalance (QCM) method and electrical measurements. The adsorption kinetics under constant relative humidity (RH) between 10% and 90% were explained using Langmuir adsorption model. Results of the measurements showed that ZnO-based fibers were found to be promising candidate for humidity sensing applications at room temperature.