Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

Chemistry

Journal

2017

Institution
Keyword
Publication

Articles 181 - 195 of 195

Full-Text Articles in Physical Sciences and Mathematics

Removal Of Pb(Ii) And Cd(Ii) From Aqueous Solution Using Alkaline-Modified Pumice Stone Powder (Psp): Equilibrium, Kinetic, And Thermodynamic Studies, Vivian Jonasi, Kaina Matina, Upenyu Guyo Jan 2017

Removal Of Pb(Ii) And Cd(Ii) From Aqueous Solution Using Alkaline-Modified Pumice Stone Powder (Psp): Equilibrium, Kinetic, And Thermodynamic Studies, Vivian Jonasi, Kaina Matina, Upenyu Guyo

Turkish Journal of Chemistry

Adsorption processes of Cd(II) and Pb(II) from aqueous solutions onto pumice stone powder (PSP) were investigated in batch mode. The influences of solution pH, contact time, adsorbent dosage, initial metal (M) concentration, and temperature on adsorption process were investigated. The kinetic and isotherm data were analysed using different model equations. The adsorption process was consistent with the Langmuir model for both metal ions with high R$^{2}$ and low $\chi^{2}$ values for both Pb(II) and Cd(II). The maximum monolayer adsorption capacities were 28.09 and 27.17 mg g$^{-1}$ for Pb(II) and for Cd(II), respectively. The pseudo-second order kinetic model explained the kinetic …


Palladium Nanoparticles Entrapped In Melamine-Formaldehyde Resin Microparticles For Mizoroki--Heck Reactions, Shaofeng Zhong Jan 2017

Palladium Nanoparticles Entrapped In Melamine-Formaldehyde Resin Microparticles For Mizoroki--Heck Reactions, Shaofeng Zhong

Turkish Journal of Chemistry

Melamine-formaldehyde resin (MFR) microparticles with average diameters of 1.06 $\mu $m were synthesized with PEG-20000 as the particle-forming agent. Palladium nanoparticles were entrapped in and adsorbed on the MFR microparticles, consecutively. Scanning electron microscopy (SEM) was used to characterize the morphologies of MFR microparticles. X-ray diffraction (XRD) and transition electron microscopy (TEM) showed that the palladium nanoparticles entrapped in the MFR microparticles dispersed much more homogeneously than those adsorbed on the MFR microparticles. Mizoroki--Heck reaction catalysis results demonstrated that the entrapped palladium catalyst had similar catalytic activity with the adsorbed palladium catalyst. Moreover, this novel entrapped palladium catalyst could be …


Catalytic Application Of 1,3,5-Triazine-Pentaethylenehexamine Polymer-Supported Palladium Nanoparticles In The Convenient Reduction Of Nitroarenes With Sodium Borohydride Or Hydrazine, Hayri̇ye Genç, Mustafa Zengi̇n, Mustafa Küçüki̇slamoğlu, Mustafa İmamoğlu, Hüseyi̇n Özkan Toplan, Mustafa Arslan Jan 2017

Catalytic Application Of 1,3,5-Triazine-Pentaethylenehexamine Polymer-Supported Palladium Nanoparticles In The Convenient Reduction Of Nitroarenes With Sodium Borohydride Or Hydrazine, Hayri̇ye Genç, Mustafa Zengi̇n, Mustafa Küçüki̇slamoğlu, Mustafa İmamoğlu, Hüseyi̇n Özkan Toplan, Mustafa Arslan

Turkish Journal of Chemistry

The catalytic activity of 1,3,5-triazine-pentaethylenehexamine (TAPEHA) polymer-supported Pd nanoparticles was investigated in the reduction of nitro arenes to the corresponding amines by NaBH$_{4}$ or N$_{2}$H$_{4}$.H$_{2}$O. Optimized reaction conditions for both systems were successfully tested on 20 nitroarenes with different characteristics. Considerably high yields (80%-98% in NaBH$_{4}$ and 85%-98% in N$_{2}$H$_{4})$ were obtained in a short time and at ambient temperature. In addition to these methods being selective against other reducible functionalities such as -CN, -Br, -Cl, and -I, the catalyst can be recovered easily and reused more than ten times.


The Multiple Effects Of Organoclay And Solvent Evaporation On Hydrophobicity Of Composite Surfaces, Haci Hasan Yolcu, Ahmet Gürses, Rabah Boukherroub Jan 2017

The Multiple Effects Of Organoclay And Solvent Evaporation On Hydrophobicity Of Composite Surfaces, Haci Hasan Yolcu, Ahmet Gürses, Rabah Boukherroub

Turkish Journal of Chemistry

A superhydrophobic high-density polyethylene (HDPE)/organoclay composite material with a water-static contact angle of $\sim $162$^{\circ}$ and low hysteresis (7$^{\circ})$ was prepared by a simple solution-intercalation technique. This one-step method consists of the insertion of organoclay, produced through cation exchange with cetyltrimethylammonium bromide (CTAB), in the polymer matrix at 120 $^{\circ}$C in xylene. In this process, evaporation of the solvent and organoclay amount are key factors for the achievement of superhydrophobicity. We characterized composite material with X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and contact angle measurements. The characterizations showed that the organoclay provides a place for …


Investigation Of Photochemical And Photophysical Properties Of Novel Silicon(Iv) Phthalocyanines And Their $\Mu $-Oxo Dimers, Ömer Güngör, Mahmut Durmuş, Vefa Ahsen Jan 2017

Investigation Of Photochemical And Photophysical Properties Of Novel Silicon(Iv) Phthalocyanines And Their $\Mu $-Oxo Dimers, Ömer Güngör, Mahmut Durmuş, Vefa Ahsen

Turkish Journal of Chemistry

The synthesis and characterization of novel tetraalkylthio (SC$_{6}$H$_{13}$ or SC$_{12}$H$_{25})$ substituted $\mu $-oxo silicon(IV) phthalocyanines (3a and 3b) and their $\mu$-oxo derivatives (4a and 4b) were described in this study. These silicon(IV) phthalocyanines were characterized using different spectroscopic techniques such as UV-Vis, $^{1}$H NMR, FT-IR, and mass and elemental analysis, as well. Furthermore, the photophysical (fluorescence quantum yields and lifetimes) and photochemical (singlet oxygen generation) properties of the newly synthesized silicon(IV) phthalocyanines (3a, 3b, 4a, and 4b) were investigated in dimethylformamide solution. The absorption and fluorescence excitation wavelengths of the studied silicon(IV) phthalocyanines were blue-shifted when they converted to their …


Understanding Of Phenolic Compound Retention Mechanisms On Pes-Uf Membrane, Amine Mnif, Meral Mouelhi, Bechir Hamrouni Jan 2017

Understanding Of Phenolic Compound Retention Mechanisms On Pes-Uf Membrane, Amine Mnif, Meral Mouelhi, Bechir Hamrouni

Turkish Journal of Chemistry

Ultrafiltration (UF) is investigated as a possible alternative to remove organic compounds from aqueous synthetic solution. This paper presents a comprehensive study towards a better understanding of phenolic compound retention mechanisms during UF processes. Thus, removal of phenol and resorcinol was studied using a polyethersulfone ultrafiltration (PES-UF) membrane. The influence of main operating conditions (feed concentration, transmembrane pressure, and pH) on the retention was evaluated. Membrane--solute interactions were found to play an important role during the process, suggesting the adsorption of the target compounds on the PES-UF membrane. The level of adsorption was consequently evaluated by measuring the quantity of …


Cyclic Voltammetry Behavior Of Tamoxifen In Different Electrolytes, Electrochemical Characterization, And Its Measurement By Differential Pulse Anodic Voltammetry, Zeinab Deris Falahieh, Mehdi Jalali, Mohammad Alimoradi Jan 2017

Cyclic Voltammetry Behavior Of Tamoxifen In Different Electrolytes, Electrochemical Characterization, And Its Measurement By Differential Pulse Anodic Voltammetry, Zeinab Deris Falahieh, Mehdi Jalali, Mohammad Alimoradi

Turkish Journal of Chemistry

Cyclic voltammetry (CV) was performed on tamoxifen (tam) using different electrodes and in various acidic electrolytes containing 10% v v$^{-1}$ methanol (MeOH). Tam oxidation was found to be most favorable using 0.1 mol L$^{-1}$ H$_{2}$SO$_{4}$. To investigate the mechanism, we performed chronoamperometry, CV at different scan rates, differential pulse anodic voltammetry (DPAV), and electrochemical impedance spectroscopy on tam-covered glassy carbon electrodes (GCEs). The electrode area, diffusion coefficient, and surface concentration ($\Gamma )$ of tam were calculated to be 0.062 cm$^{2}$, 3.65 $\times $ 10$^{-6}$ cm$^{2}$ s$^{-1}$, and 3.2 $\times $ 10$^{-10}$ mol cm$^{-2}$ respectively. Then the effects of different parameters …


Methanolysis Of Jatropha Curcas Oil Using K$_{2}$Co$_{3}$/Cao As A Solid Base Catalyst, Gajanan Sahu, Sujan Saha, Sudipta Datta, Prakash Chavan, Satyanarayan Naik Jan 2017

Methanolysis Of Jatropha Curcas Oil Using K$_{2}$Co$_{3}$/Cao As A Solid Base Catalyst, Gajanan Sahu, Sujan Saha, Sudipta Datta, Prakash Chavan, Satyanarayan Naik

Turkish Journal of Chemistry

Biodiesel, fatty acid methyl ester produced by the transesterification of vegetable oil with methanol, is a promising alternative to petroleum-based diesel fuel. In the present study, the methanolysis of high free fatty acid (FFA) $Jatropha$ $curcas$ oil in a transesterification reaction using K$_{2}$CO$_{3}$/CaO solid base catalyst was studied. The various reaction parameters in the transesterification reaction were also discussed. The catalyst was characterized by means of Fourier transform infrared, X-ray diffraction, temperature programmed desorption of CO$_{2}$, scanning electron microscopy, particle size analyzer, true density, and surface area analyzer. The optimum conversion of jatropha oil was 92% when the transesterification reaction …


Investigation Of Photoinduced Polymerization Of Doxycycline-Imprinted Hydrogels: Effect Of Template On Initiator Reactivity, Conversion, And Reaction Rate, Di̇lek Dalgakiran, Tuğçe İnan, Fatma Seni̇ha Güner Jan 2017

Investigation Of Photoinduced Polymerization Of Doxycycline-Imprinted Hydrogels: Effect Of Template On Initiator Reactivity, Conversion, And Reaction Rate, Di̇lek Dalgakiran, Tuğçe İnan, Fatma Seni̇ha Güner

Turkish Journal of Chemistry

Photopolymerization kinetics of doxycycline hyclate (DOX)-imprinted hydrogels were monitored by real-time Fourier transform infrared spectroscopy and differential photocalorimetry. 2-Hydroxyethyl methacrylate-based hydrogels were synthesized by using ethylene glycol dimethacrylate as a cross-linker, acrylic acid (AA) as a functional monomer, and 2,2-dimethyl-2-hydroxy acetophenone as a photoinitiator. For imprinting DOX in hydrogels, the molar ratio of template to functional monomer (DOX:AA) was chosen as 1:8 and 1:16. The polymerization was achieved at two different initiator concentrations. The conversion and reaction rate were calculated as a function of the molar ratio of template, and the results were compared to those of nonimprinted ones. In …


Synthesis Of Novel 5-Substituted Phenyl-3-(P-Isopropylphenyl)-1-Phenylformazan And Their Biological Activities, Ayşe Şahi̇n Yağlioğlu, Hülya Şenöz Jan 2017

Synthesis Of Novel 5-Substituted Phenyl-3-(P-Isopropylphenyl)-1-Phenylformazan And Their Biological Activities, Ayşe Şahi̇n Yağlioğlu, Hülya Şenöz

Turkish Journal of Chemistry

Novel 1-substituted 3-(p-isopropylphenyl)-5-phenylformazans (3a--g) were synthesized and characterized by elemental analysis, $^{1}$H NMR, and FT-IR techniques and UV-visible spectroscopy. Antiproliferative activities of 3a--g against HeLa and C6 cells were determined using the BrdU cell proliferation ELISA assay. 5-Florouracil was used as the positive control. The effects of substituents (--H, --CH$_{3}$, and --I) and their positions ($ortho$, $meta$, and $para$) on the antiproliferative activities were evaluated. The results of the assay indicate that I substituent exhibited higher activity against the cells at the $meta$ and $para$ positions than --CH$_{3}$ and --H substituents. 3a--g exhibited both high antiproliferative activities against C6 cells …


Separation And Recovery Of Gallium(Iii) Ions From Aqueous Phase By Liquid--Liquid Extraction Using A Novel Extractant, Cyphos Il 101, Sumitra Nayak, Niharbala Devi Jan 2017

Separation And Recovery Of Gallium(Iii) Ions From Aqueous Phase By Liquid--Liquid Extraction Using A Novel Extractant, Cyphos Il 101, Sumitra Nayak, Niharbala Devi

Turkish Journal of Chemistry

The present study describes the extraction behavior of gallium(III) using a novel ionic liquid trihexyl(tetradecyl) phosphonium chloride (Cyphos IL 101) diluted with kerosene from acidic chloride medium. The extraction of gallium was found to depend on the hydrochloric acid concentration and quantitative extraction of gallium took place at 2.0 mol/L HCl concentration. The nature of the extracted complex in the organic phase was determined using Job's method and proposed to be [R$_{3}$R$^\prime $PGaCl$_{4}$]. The loading capacity of 5.0 $\times$ 10$^{-3}$ mol/L Cyphos IL 101 was determined to be 320.0 mg/L. Two stages of stripping were required for complete removal of …


Synthesis Of Pds/Zns--Cds-Type Photocatalysts Using Zns As Sulphide Source, Radu Banica, Petrica Linul, Cristina Mosoarca Jan 2017

Synthesis Of Pds/Zns--Cds-Type Photocatalysts Using Zns As Sulphide Source, Radu Banica, Petrica Linul, Cristina Mosoarca

Turkish Journal of Chemistry

In this work, a new method for the growth of large CdS crystals into PdS/ZnS--CdS-type photocatalysts is presented. In order to accomplish this, in the first stage zinc sulphide was synthesised and hydrothermally crystallised. In the second stage, after PdS decoration, the recrystallised zinc sulphide was utilised as sulphur source for the synthesis of PdS/ZnS--CdS-type photocatalysts. The photocatalysts were characterised by X-ray diffraction, transmission electron microscopy, energy dispersive X-ray spectroscopy, and diffuse reflectance spectroscopy. In the third stage magnetic polymer supports were manufactured and loaded with photocatalyst. Finally photocatalysis experiments under blue light illumination were conducted for the hydrogen evolution …


Naked Eye And Smartphone Applicable Detection Of Toxic Mercury Ions Using Fluorescent Carbon Nanodots, Burcu Baç, Rükan Genç Jan 2017

Naked Eye And Smartphone Applicable Detection Of Toxic Mercury Ions Using Fluorescent Carbon Nanodots, Burcu Baç, Rükan Genç

Turkish Journal of Chemistry

Chitosan passivated carbon nanodots (C-Dots$_{CHIT})$ were synthesized from expired molasses via a simple and green thermal synthesis procedure. As-synthesized C-Dots were nitrogen-doped (NC-Dots$_{CHIT})$ by posttreatment with liquid ammonia and used as nanoprobes for fluorometric detection of mercury ions (Hg(II)$_{aq.})$. Fluorescence response of NC-Dots$_{CHIT}$ in the presence of mercury was evaluated and compared with that of the polyethylene glycol passivated C-Dots$_{PEG}$. This sensing strategy using NC-Dots$_{CHIT}$ displayed a wide linear working range from 1.25 $\mu $g/mL to 43.54 $\mu $g/mL with a detection limit of 1.41 $\mu $g/mL. The fluorescence of C-Dots$_{PEG}$ did not show any significant change upon mercury addition. …


Ultrasound-Assisted Surfactant/Ionic Liquid Aqueous Two-Phase System Extraction Prior To High Performance Liquid Chromatography For The Determination Of Tetracyclines In Milk And Honey Samples, Hayri̇ye Mi̇ne Antep, Taşkin Mumcu, Kami̇l Bostanci, Serap Seyhan Bozkurt, Melek Merdi̇van Jan 2017

Ultrasound-Assisted Surfactant/Ionic Liquid Aqueous Two-Phase System Extraction Prior To High Performance Liquid Chromatography For The Determination Of Tetracyclines In Milk And Honey Samples, Hayri̇ye Mi̇ne Antep, Taşkin Mumcu, Kami̇l Bostanci, Serap Seyhan Bozkurt, Melek Merdi̇van

Turkish Journal of Chemistry

In this work, an ultrasonic-assisted surfactant/ionic liquid aqueous two-phase system (ATPS) extraction method was developed to extract six tetracycline antibiotics from food samples before their chromatographic determination using high performance liquid chromatography. The ATPS was formed with 1-allyl-3-methyl-imidazolium bromide, Triton X-100, and dipotassium hydrogen phosphate. The parameters including type and amount of surfactant, ionic liquid and salt, pH of sample solution, and sonication time were optimized. Under the optimized conditions, linear calibration curves of the six tetracyclines were obtained in the range of 10--500 $\mu $g L$^{-1}$ with $>$ r$^{2} =$ 0.990 (n $=$ 9). The proposed green analytical …


Adsorption Of Copper Ions And Alizarin Red S From Aqueous Solutions Onto A Polymeric Nanocomposite In Single And Binary Systems, Omnia Ali, Sahar Mohamed Jan 2017

Adsorption Of Copper Ions And Alizarin Red S From Aqueous Solutions Onto A Polymeric Nanocomposite In Single And Binary Systems, Omnia Ali, Sahar Mohamed

Turkish Journal of Chemistry

Adsorption of Cu(II) ions and alizarin red S (ARS) has been studied using beads of chitosan (CS) and a chitosan/ZnO nanorod composite (CS-ZnO) in single and binary systems. The beads were synthesized and characterized using Fourier transform infrared spectroscopy, X-ray diffraction, high-resolution transmission electron microscopy, scanning electron microscopy, and energy dispersive X-ray analysis. Factors affecting adsorption of Cu(II) ions and ARS such as pH and initial concentrations as well as adsorption kinetics, isotherms, thermodynamics, reusability, and competitive adsorption in binary systems were studied. The results showed that the adsorption kinetics and isotherm data for both adsorbates followed a pseudo-second-order model …