Nursel Can

Toluene vapor sensing characteristics of novel copper(II), indium(III), mono-lutetium(III) and tin(IV) phthalocyanines substituted with 2,6-dimethoxyphenoxy bioactive moieties

This study presents the synthesis, characterization and toluene sensing properties of copper(II), indium(III) acetate, mono-lutetium(III) acetate and tin(IV) phthalocyanines substituted with 2,6-dimethoxyphenol bioactive groups at the peripheral and non-peripheral positions. The effects of the substituent’s position on the toluene vapor detection capabilities of these compounds were investigated. Adsorption data were analyzed by using first-order and Elovich equations in order to investigate the adsorption kinetics. It was found that the kinetics of the toluene adsorption strongly depends on the position of the substituent groups. Our results showed that the Elovich equation fits the experimental data well for non-peripherally substituted Pc based sensors, while the pseudo first-order model best describes the adsorption data for peripheral substituted Pc based sensors.

The effects of substituent position on kinetics of benzene vapour adsorption onto 3-phenylphenoxy substituted metal-free and metallo-phthalocyanines thin films

The preparation of metal-free, Zn(ii), In(iii), and Cu(ii)-phthalocyanines containing tetrakis-(3-phenylphenoxy) groups was achieved by employing 3-(3-phenylphenoxy)phthalonitrile (1) and 4-(3-phenylphenoxy)phthalonitrile (2) as starting materials. The phthalonitriles and phthalocyanines were characterized by elemental analysis, infrared, proton nuclear magnetic resonance, ultraviolet-visible, and matrix-assisted laser desorption/ionization time-of-flight mass spectroscopic techniques. The effect of the substituent group on the kinetics of benzene vapour adsorption onto these novel compounds was examined using three kinetics models: the pseudo first-order model, the Elovich equation, and a simple adsorption-desorption model. Results show that the benzene adsorption kinetics strongly depend on the position of the substituent groups.

Meyer-Neldel Rule in Ac Conductivity of Cu Doped ZnO Thin Films

Ac charge transport mechanisms have been comparatively investigated in ZnO thin films having different Cu dopant. A comparative study of the applicability of quantum mechanical tunelling and correlated barrier hopping model to obtained ac electrical conductivity results has been performed. Comparing the temperature dependence of the frequency exponent shows that the correlated barrier hopping model best describes the experimental data on the ac conductivity in ZnO:Cu thin films. In order to gain an understanding of the applicability of Meyer-Neldel rule, the dependence of the thermal activation energy on Cu doping concentration in these films has also been studied. The obtained experimental results indicated that Meyer-Neldel rule can be succesfully applied ac conductivity data for highly Cu doped films but not others which has been explained on the basis of distribution variations in density of states.

Investigation on aging mechanism of polyester under combined stresses

The physical properties of polyester film, such as thermal stability, combined with its mechanical properties, such as tensile break strength, and its electrical strength make it the preferred material for a wide variety of electrical insulation applications. Therefore, polyesters are widely used as insulating material for electric power system equipment such as cables, motors, transformers, and capacitors, since its high dielectric constant and resistance to degradation in high voltage and thermal stresses makes it ideal for mechanical barriers in wire and cable applications. For instance, in transformers and other high-voltage distribution equipment, polyester film is used to wrap the conductors [1]-[3].

Highly sensitive heavy metal ion detection using AlQ3 microwire functionalized QCM

Tris(8-hydroxyquinoline) aluminum (Alq3) microwires was successfully synthesized for the fabrication of Alq3 microwires-coated QCM sensors to detect the heavy metal ions in aqueous solution. AT-cut quartz crystal microbalance (QCM) of 10 MHz fundamental resonance frequency having gold electrodes were used as transducers. Typical measuring cycle consisted of repeated flow of target measurands through the flow cell and subsequent washing to return the baseline. The QCM results indicated that the Alq3 microwires exhibit excellent sensitivity, stability and short response-recovery time, which are much attractive for the development of portable and highly sensitive heavy metal ion sensors in water samples.