Özkan, Seher Fehime
Loading...
Profile URL
Name Variants
Çakıcıoğlu Özkan, Seher Fehime
Cakicioglu-Ozkan, F.
Cakicioglu-Ozkan, Fehime
Cakicioglu Ozkan, Seher Fehime
Çakicioğlu Özkan, Seher Fehime
Çakıcıoğlu-Özkan, F.
Çakıcıoğlu-Özkan, Fehime
Ozkan, F
Ozkan, F.
Özkan, F
Özkan, F.
Özkan, Fehime Çakıcıoğlu
Ozkan, Fehime Cakicioglu
Ozkan, Fehime
Cakicioglu-Ozkan, F.
Cakicioglu-Ozkan, Fehime
Cakicioglu Ozkan, Seher Fehime
Çakicioğlu Özkan, Seher Fehime
Çakıcıoğlu-Özkan, F.
Çakıcıoğlu-Özkan, Fehime
Ozkan, F
Ozkan, F.
Özkan, F
Özkan, F.
Özkan, Fehime Çakıcıoğlu
Ozkan, Fehime Cakicioglu
Ozkan, Fehime
Job Title
Email Address
fehimeozkan@iyte.edu.tr
s.fehimeozkan@gmail.com
s.fehimeozkan@gmail.com
Main Affiliation
03.02. Department of Chemical Engineering
Status
Current Staff
ORCID ID
Scopus Author ID
Turkish CoHE Profile ID
Google Scholar ID
WoS Researcher ID
Sustainable Development Goals
1NO POVERTY
0
Research Products
2ZERO HUNGER
2
Research Products
3GOOD HEALTH AND WELL-BEING
0
Research Products
4QUALITY EDUCATION
1
Research Products
5GENDER EQUALITY
0
Research Products
6CLEAN WATER AND SANITATION
8
Research Products
7AFFORDABLE AND CLEAN ENERGY
11
Research Products
8DECENT WORK AND ECONOMIC GROWTH
4
Research Products
9INDUSTRY, INNOVATION AND INFRASTRUCTURE
12
Research Products
10REDUCED INEQUALITIES
0
Research Products
11SUSTAINABLE CITIES AND COMMUNITIES
0
Research Products
12RESPONSIBLE CONSUMPTION AND PRODUCTION
10
Research Products
13CLIMATE ACTION
13
Research Products
14LIFE BELOW WATER
3
Research Products
15LIFE ON LAND
1
Research Products
16PEACE, JUSTICE AND STRONG INSTITUTIONS
0
Research Products
17PARTNERSHIPS FOR THE GOALS
0
Research Products
Documents
24
Citations
535
h-index
13
Documents
0
Citations
0
Scholarly Output
34
Articles
17
Views / Downloads
35154/20106
Supervised MSc Theses
10
Supervised PhD Theses
5
WoS Citation Count
364
Scopus Citation Count
391
Patents
0
Projects
12
WoS Citations per Publication
10.71
Scopus Citations per Publication
11.50
Open Access Source
33
Supervised Theses
15
| Journal | Count |
|---|---|
| Journal of Thermal Analysis and Calorimetry | 3 |
| Key Engineering Materials | 2 |
| Applied Catalysis A: General | 2 |
| Central European Journal of Chemistry | 1 |
| Chemical Engineering Communications | 1 |
Current Page: 1 / 3
Scopus Quartile Distribution
Competency Cloud
34 results
Scholarly Output Search Results
Now showing 1 - 10 of 34
Article Kinetics of Proton Transfer in the Zeolitic Tuff(Central European Science Journals, 2009) Çakıcıoğlu Özkan, Seher Fehime; Özkan, Seher Fehime; Polatoğlu, İlkerThe kinetics of a proton transfer into dilute acid solutions containing natural zeolitic tuff was studied by following the pH evolution of the liquid phase. Four different solutions with tuff contents of 9, 3, 1 and 0.5 (% wt) and three different particle size fractions (≤ 2000 μm) were studied. The proton concentration of the solution was decreased by increasing the zeolite amount and decreasing the particle size fraction. The proton transfer reaction was analyzed with chemical reactions and diffusion model equations. Analysis shows that the adsorption and/or ion exchange are possible mechanisms and are expressed by a second order reaction model.Master Thesis Gas adsorption in volumetric system(Izmir Institute of Technology, 2003) Becer, Metin; Özkan, Seher FehimeIn this study, nitrogen adsorption on natural zeolitic tuff from Gördes, (Fındıcak) region and on its acid treated forms was studied. The natural zeolite, identified as clinoptilolite, has been treated with HCl, H2SO4, HNO3, and H3PO4 solutions at several concentrations to obtain the acid treated forms. Structural modifications arising from the acid treatments were determined by the techniques, namely XRD, FTIR, ICP, EDX, SEM, DTA, TGA, and microcalorimeter. Adsorption characteristics of zeolites, such as external and total surface areas, micropore volumes and pore size distributions were compared.Acid treatment of natural zeolite showed that as the acid concentrations were increased, more cations were removed from the structure, changing the Si/Al ratios from 4.04 (original zeolite) to 5.35 with H2SO4, to 6.39 with HNO3, to 10.8 with HCl and to 5.01 with H3PO4 treatments respectively. With acid treatment, the maximum nitrogen adsorption capacity at P/Po . 0.89 of natural zeolite (0.015 cm3/g) was increased to 0.089, 0.090, 0.086, and 0.050 cm3/g for HCl, HNO3, H2SO4 and H3PO4 treatments respectively. Nitrogen adsorption capacities of the zeolites increased with increasing Si/Al ratios, but further increase in concentrations caused to decrease the adsorption capacity for HCl and HNO3 treatments. HCl behaved in a different way that, dilute (1M) and highly concentrated (10 M) solutions has effect on the framework structure much more than the middle range concentrations (3 M and 5 M HCl) decreasing the nitrogen adsorption after Si/Al . 8.4 (5 M HCl).Dubinin-Raduskhevich model was used to determine the volume accessible to nitrogen (limiting micropore volume). It increased with increasing Si/Al ratios, but further increase in concentrations caused to decrease in microporous structure. The highest limiting micropore volumes (0.078 and 0.082 cm3/g), and Langmuir surface areas (213 and 226 m2/g) were obtained with the 5 M HCl and 2 M HNO3 treated samples respectively without any noticable loss in crystallinity.Master Thesis Preparation of Natural Zeolite Supported Tio2 Composites for Removal of Terephthalic Acid(Izmir Institute of Technology, 2014) Deliismail, Özgün; Çakicioğlu Özkan, Seher Fehime; Helvacı, Şerife ŞerefThis study focuses on the preparation of natural zeolite supported TiO2 composites for the removal of model pollutant, terepththalic acid (TPA) via sorption. Natural zeolite was purified and used to prepare natural zeolite supported TiO2 adsorbents. Prior to sorption, the adsorbents were characterized by Scanning Electron Microscopy, Volumetric Adsorption Instrument, X-ray Diffractometer, Fourier Transformer Infrared, Induced Coupled Plasma Atomic Emmision Spectroscopy, and Thermal Gravimetric Analyzer. It was deduced that natural zeolite was clinoptilolite rich low (Ca) silicate. The sorption studies of TPA on adsorbents were applied in dark conditions at room temperature by altering adsorbent amount (0.2-1.5 g/l) and initial TPA concentration (20-60 ppm). It was observed that the amount of adsorbed TPA per unit mass of adsorbent decreased with increasing adsorbent amount, and sorption percent was unchanged (about 72%). This can be explained by the affinity of adsorbents to water molecules more than TPA molecules. Much more number of TPA molecules was allocated on the clinoptilolite than TiO2 composites. Sorption mechanism was identified by fitting the kinetic data to diffusion (Weber-Morris model, intraparticle/external diffusion) and reaction models (First order and pseudo second order model). First order reaction model was well correlated to experimental data for sorption process. Comparing pore size of the adsorbents to molecular size of TPA indicates that main contribution to intraparticle diffusion was the intercrystalline diffusion. Intraparticle diffusion was not the sole rate-limiting step due to the existence of external resistance. Biot and Weber-Morris calculations corroborated these results. In the future, photocatalytic performance of these adsorbents will also be tested.Article Citation - WoS: 3Citation - Scopus: 4Photocatalytic Degradation of Aquatic Organic Pollutants With Zn- and Zr-Based Metalorganic Frameworks: Zif-8 and Uio-66(TÜBİTAK - Türkiye Bilimsel ve Teknolojik Araştırma Kurumu, 2022) Çalık, Fatma Defne; Erdoğan, Bilgesu; Yılmaz, Esra; Saygı, Gizem; Çakıcıoğlu-Özkan, FehimeWater treatment has been an essential issue with the increasing population over 40 years. Researchers center on the major organic pollutants, such as dyes, pesticides, and pharmaceutical products. Photocatalytic degradation is one of the promising methods for aquatic organic pollutant treatment. Over the years, scientists have been working on developments for photocatalysts to enhance their pollutant degradation performances. From the reviewed studies, it is seen that properties like surface area, chemical, mechanical, and thermal stability, and uniform distribution of active sites are crucial, and an increase in these properties provides better degradation efficiency. In this sense, metal-organic frameworks as photocatalysts can be considered more advantageous. This study focuses on the organic aquatic pollutant degradation studies by using well-known MOFs like ZIF-8 and UiO-66 photocatalysts. Mainly the organic dye (RhB, MB, MO, etc.) degradation efficiencies of ZIF-8 and UiO-66 have been achieved to 100%. Recently, the degradation capacities of various pharmaceuticals such as diazinon, acetaminophen, levofloxacin, and sulfamethoxazole have also been investigated. According to the reviewed studies, ZIF-8 and UiO-66 can be considered remarkable photocatalysts for the degradation of organic pollutants.Master Thesis Adsorption of Methane Reformer Off-Gas Components in a Column Packed With Cu, Al,ti and Zn Based Organic Frameworks(Izmir Institute of Technology, 2016) Kanaltı, Gaye; Çakıcıoğlu Özkan, Seher FehimeWithin the past decade, CO2 emissions from fossil fueled power plants has accelerated rapidly as a result of the increase in energy consumption associated with industrial development all over the world. Beyond the necessity of reduction in CO2 emissions, concerning on the crude oil reserves depletion induced the urgent need of transition to more efficient, renewable, cleaner and cheaper fuel, hydrogen. In the world, most of the hydrogen is produced by hydrogen-rich stream methane reformer (SMR) off gas streams composed of 80-60% H2, 15-25% CO2, 3-6% CH4 and 1-3% CO, thereby separation of SMR components became more of an issue. In this study, adsorption based separation of SMR components were investigated in a column packed with copper (CuTPA, (SLang: 776 m2g-1)), aluminum (AlTPA, (SLang: 1330 m2g-1)), titanium (TiTPA, (SLang: 1835 m2g-1)) and zinc (ZnTPA, (SLang: 1023 m2g-1)) based organic frameworks (MOFs). The pure gas adsorption studies on equimolar CO2/H2, CH4/H2 and CO/H2 systems and the equimolar mixture of CO2/CH4 system were carried out and the experimental breakthrough curves were obtained at three different feed flow rates (10, 20 and 30 mL/min) at three column pressure (1, 5 and 10 bar) at 303 K. The highest adsorption capacities of all MOFs were achieved at 30 mL/min of feed rate and 10 bar operating pressure, at these conditions the non-adsorptive behavior of hydrogen on the aforementioned MOFs was ensured. The amounts of CO2 adsorbed were calculated as 1.61, 5.54, 5.20 and 2.11 mmolCO2/g, while adsorbed CH4 amounts were 1.50, 3.16, 3.25 and 1.90 mmol CH4/g and the adsorbed CO amounts were 1.47, 2.59, 1.91 and 1.83 mmol CO/g on CuTPA, AlTPA, TiTPA and ZnTPA, respectively. The highest selectivity for CO2 over CH4 was attained on TiTPA as 8.0 at 10 mL/min feed rate of CO2/CH4 mixture at atmospheric column pressure and 303 K. The experimental adsorption isotherms of SMR components were fitted well with Langmuir and virial models and the best fitted model parameters were evaluated for each MOF.Article Citation - WoS: 19Flexible Poly(vinyl Chloride)-Zeolite Composites for Dye Adsorption From Aqueous Solutions(Taylor and Francis Ltd., 1996) Balköse, Devrim; Ulutan, Sevgi; Çakıcıoğlu Özkan, Seher Fehime; Ülkü, Semra; Köktürk, UğurFlexible poly(vinyl chloride) (PVC) composites having natural zeolite clinoptillolite were prepared by plastisol-plastigel technology. Adsoption of methylene blue on each raw material and on composites was studied both from an equilibrium and a rate approach. It was observed that the adsorption capacity of zeolite decreased when it was embedded in composites. The equilibrium uptake of methylene blue increased with an increasing zeolite fraction in composites. Methylene blue was adsorbed from a 0.02 g·cm-3 aqueous solution slowly, but was nearly adsorbed completely with a composite having a 0.3 volume fraction of zeolite. The effective diffusion coefficient of methylene blue in composites was of the order of 10-13 m2·s-1 and decreased with increasing filler fraction.Conference Object Citation - WoS: 2Citation - Scopus: 2Investigation of the Permeability of Pure Gases in Sol-Gel Derived Al 2o 3 Membrane(Trans Tech Publications, 2004) Topuz, Berna; Çiftçioğlu, Muhsin; Özkan, FehimeThe preparation, characterization and pure gas permeation of sol-gel derived alumina membranes were investigated in this work. The effects of acid concentration/type and water content on the particle size in the sols and pore size distributions of the unsupported membrane were investigated by N 2 adsorption/desorption isotherms and Dynamic Light Scattering. Increasing the H +/Al 3+ mole ratio from 0.1 to 0.25 caused the hydrodynamic sol particle size and BJH pore size to decrease from 65 to 30 nm and 3.6 to 2.9 nm, respectively. The pore size increased from 2.8 nm to 3 nm upon increasing the calcination temperature from 500 to 600°C. Unsupported membranes were heat treated in the 200 to 1200 °C range for the characterization of the phase structure. Pinhole and crack free alumina membranes about 3 μm (2-layer) in thickness was observed from the SEM pictures with insignificant infiltration. The CO 2 permeability through the double layer γ-Al 2O 3 membrane calcined at 600 °C was 2.25*10 -7 mol/m 2.s.Pa, and had a slight pressure dependence indicating Knudsen Diffusion and Laminar Flow being the effective transport mechanisms. Upon the calcination of a similar 2-layer alumina membrane at 500°C, the CO 2 permeability decreased to 1.51 *10 -8 mol/m 2.s.Pa. without pressure dependence.Doctoral Thesis Heat and Mass Transfer Characteristics of Adsorbents in Heat Pump and Refrigerator(01. Izmir Institute of Technology, 2023) Gündoğan, Şefika Çağla; Çakıcıoğlu Özkan, Seher FehimeDue to increasing drought, pandemic and climate crisis in recent years, researchers have increased their studies on environmentally friendly energy use. Although there are technological developments in the production of energy from renewable energy sources, the storage of this produced energy is still a problem that awaits a solution. At this point, adsorption heat pumps with high primary energy efficiency come to the fore as a developing technology and attract the attention of researchers. However, low heat transfer properties in the adsorbent bed reduce the performance of adsorption heat pumps and limit their applications. The aim of this thesis was to improve the performance of the adsorption heat pump by increasing the effective thermal conductivity within the adsorbent bed. Two methods have been employed to enhance the effective thermal conductivity. In the first method, which was unconsolidated adsorbent bed design, it was aimed to increase the thermal conductivity of the bed with metal additives with a continuous structure. In the second method, which is known as consolidated bed design, the effective thermal conductivity of zeolite 13X was tried to be enhance with a high conductive material, reduced graphene oxide. In the experimental studies, it was observed that the thermal conductivity increased from 0.12 W/m.K to 0.28 W/m.K in unconsolidated bed design by means of fin-shaped metal additive. In consolidated adsorbent bed design, the effective thermal conductivity of the Graphene/Zeolite 13X (1 wt% Graphene) was determined as 0.1613 W/m.K. In theoretical studies, the effect of thermal conductivity in the temperature, pressure and adsorbate concentration was investigated. The indirect and direct effects of effective thermal conductivity on specific cooling/heating power (SCP/SHP) and coefficient of performance (COP) values were examined. Although the effect of thermal conductivity on COP was ignored in most of the studies in the literature, it was observed that COP increased from 0.01 to 0.10 when thermal conductivity increased from 0.12 W/m.K to 1 W/m.K.Article Citation - WoS: 12Citation - Scopus: 17Diffusion Mechanism of Water Vapour in a Zeolitic Tuff Rich in Clinoptilolite(Springer Verlag, 2008) Çakıcıoğlu Özkan, Seher Fehime; Ülkü, SemraThe adsorption kinetics of H2O in a clinoptilolite rich zeolitic tuff was experimentally investigated at 18°C. In the identification of the diffusion mechanism the isothermal adsorption model equation was used. It was found out that the intraparticle mass transfer becomes more dominant over the heat transfer with increase in particle size and the adsorptive dose pressure. Although initially intraparticle mass transfer was the controlling resistance later external heat transfer also contributes to the transfer mechanism.Conference Object Citation - Scopus: 1Effects of Processing on the Properties and Permeability of Pure Gases Through Sol-Gel Silica Membranes(Trans Tech Publications, 2004) Topuz, Berna; Çiftçioğlu, Muhsin; Özkan, FehimeN2, O2 and CO2 pure gas permeation through sol-gel derived silica membranes were determined and the effects of processing parameters on the microstructure of the membrane was investigated. Silica sols were prepared in an alcoholic solution by hydrolysis and condensation of TEOS as a function of acid content. The thickness of the silica membranes was determined to be about 2μm and significant infiltration into the support was observed from the SEM pictures. The supported membranes were heat treated in the 50-400°C. The N2 permeabilities of silica membranes varied in the 2.2*10-10-2.7*10-8 mol/m2.s.Pa range for single layer membranes dipped for 10s. in the sol. The CO2 permeability of these membranes varied in the 1.2*10-9-6.95 *10-8 mol/m2.s.Pa range. The sols became viscous and gelled at 50°C in 16 hours. The O2 permeability increased with aging time. The optimum dipping time during processing was determined to be 10 seconds. The increase in the acid content of the sols were observed to increase permeabilities of the membranes significantly.