Browsing by Author "Yargı, Önder"
Now showing items 1-10 of 10
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Conductivity percolation of carbon nanotubes (CNT) in polystyrene (PS) latex film
Authors:Uğur, Şaziye; Yargı, Önder; Pekcan, Önder
Publisher and Date:(Canadian Science Publishing Nrc Research Press, 2010)In this study the effect of multiwalled carbon nanotubes (MWNT) on film formation behaviour and electrical conductivity properties of polystrene (PS) latex film was investigated by using the photon transmission technique and electrical conductivity measurements. Films were prepared by mixing PS latex with different amounts of MWNTs varying in the range between 0 and 20 wt%. After drying MWNT content films were separately annealed above the glass transition temperature (T-g) of PS ranging from 100 ...
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Diffusion energies of oxygen diffusing into polystyrene (PS)/poly (N-isopropylacrylamide) composites
Diffusion coefficient of oxygen penetrating into polystyrene (PS) latex/poly (N-isopropylacrylamide) (PNIPAM) microgel composite films were measured using Fluorescence technique. Three different (5 15 and 40wt%) PS content films were prepared from PS/PNIPAM mixtures. Diffusivity of PS/PNIPAM composite films were studied by diffusion measurements which were performed over the temperature range of 24-70 degrees C. Pyrene was used as the fluorescent probe. The diffusion coefficients (D) of oxygen ...
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Film Formation of Poly (methyl methacrylate) Latex With Pyrene Functional Poly (divinylbenzene) Microspheres Prepared by Click Chemistry
Authors:Uğur, Şaziye; Yargı, Önder; Durmaz, Yasemin Yuksel; Karagöz, Bünyamin; Bıçak, Niyazi; Yağci, Yusuf; Pekcan, Önder
Publisher and Date:(Wiley-Blackwell, 2011)This work reports on the application of steady state fluorescence (SSF) technique for studying film formation from poly(methyl methacrylate) (PMMA) latex and poly(divinylbenzene) (PDVB) microsphere composites. Pyrene (P) functionalized PDVB cross-linked spherical microspheres with diameters of 2.5 mu m were synthesized by using precipitation polymerization technique followed by click coupling reaction. The diameter of the PMMA particles prepared by emulsion polymerization were in the range of ...
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Fluorescence quenching method for monitoring oxygen diffusion into PS/CNT composite films
Oxygen permeabilities of nanocomposite films consisting of multi wall carbon nanotubes (MWNT) and polystyrene (PS) were determined to investigate the oxygen diffusion depending on MWNT and temperature. A method which is based on quenching of an excited phosphorescent by oxygen was applied for the measurements. The composite films were prepared from mixtures of (MWNT) and surfactant-free pyrene (P)-labeled (PS) latexes of various compositions at room temperature. These films were then annealed at ...
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Measurement of oxygen diffusion in PS/PNIPAM films using fluorescence quenching
The diffusion of oxygen into pyrene labelled polystyrene (PS) latex/poly(N-isopropylacrylamide) (PNIPAM) composite films (PS/PNIPAM) was studied based on PS content with the use of fluorescence quenching method. Fluorescence experiments were carried out on composite films containing pyrene as a sensor dye. The Stern-Volmer equation for fluorescence quenching is combined with Fick's law for diffusion to derive mathematical expressions. Diffusion coefficients (D) were produced and found to be decreased ...
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Oxygen Diffusion into Multiwalled Carbon Nanotube Doped Polystrene Latex Films Using Fluorescence Technique
Authors:Yargı, Önder; Ugur, Saziye; Pekcan, Önder
Publisher and Date:(Springer/Plenum Publishers, 2013)This study examines the oxygen diffusion into polystyrene (PS) latex/multiwalled carbon nanotube (MWNT) nanocomposite films (PS/MWNT) consisting of various amounts of MWNT via steady state fluorescence technique (SSF). PS/MWNT films were prepared from the mixture of MWNT and pyrene (P)-labeled PS latexes at various compositions at room temperature. These films were then annealed at 170 A degrees C above glass transition (T-g) temperature of PS. Fluorescence quenching measurements were performed ...
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Oxygen diffusion into polystyrene-bentonite films
A simple fluorescence technique is proposed for the measurement of the diffusion coefficient of oxygen into polystyrene-clay composite films. The composite films were prepared from the mixture of surfactant-free pyrene (P)-labeled polystyrene latexes (PS) and modified bentonite (MNaLB) at various compositions at room temperature. These films were annealed at 200 degrees C above the glass transition (T-g) temperature of polystyrene for 10 min. Oxygen diffusion into the films was monitored with ...
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Percolation and Film Formation Behaviors of MWNT/PS Nanocomposites
This study involves the investigation of film formation and electrical conductivity properties of polystrene (PS) latex/multi-walled Carbon nanotube (MWNT) composites. Films prepared from PS/MWNT mixtures with different MWNT content were separately annealed above glass transition temperature of PS. Film formation stages of PS/MWNT composites were followed by monitoring the change in transmitted light intensity I-tr. The surface conductivity of films was found to increase dramatically above 4 wt% ...
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Polymer/carbon nanotube composite film formation: A fluorescence study
In this study the effect of multi-walled Carbon nanotube (MWNT) on film formation behavior of Polystrene (PS) latex film was investigated by using steady state fluorescence technique. Films were prepared by mixing of pyrene (P)-labeled PS latex with different amounts of MWNTs varying in the range between 0 and 20 wt%. After drying MWNT containing films were separately annealed above glass transition temperature (T-g) of PS ranging from 100 to 270 degrees C for 10 min. In order to monitor film ...
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Temperature dependence of oxygen diffusion into polymer/carbon nanotube composite films
This study examines the transport properties of polystyrene (PS)/multiwalled carbon nanotube (MWNT) composite films taking into consideration both MWNT composition and temperature via fluorescence technique. Three different (3 15 and 40 wt%) MWNT content films were prepared from PS/MWNT mixtures by annealing them at 170 degrees C above the glass transition temperature of PS for 10 min. The diffusivity of the PS/MWNT composite was determined by performing oxygen (O2) diffusion measurements within ...