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

Physical Sciences and Mathematics Commons™

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

Articles 841 - 870 of 2730

Full-Text Articles in Physical Sciences and Mathematics

Effect Of Polyvinyl Alcohol/Chitosan Blend Ratios On Morphological, Optical, And Thermal Properties Of Electrospun Nanofibers, Gökhan Açik, Musa Kamaci, Burak Özata, Cahi̇de Eli̇f Özen Cansoy Jan 2019

Effect Of Polyvinyl Alcohol/Chitosan Blend Ratios On Morphological, Optical, And Thermal Properties Of Electrospun Nanofibers, Gökhan Açik, Musa Kamaci, Burak Özata, Cahi̇de Eli̇f Özen Cansoy

Turkish Journal of Chemistry

In this study, the electrospinning method was used to prepare polyvinyl alcohol (PVA)/chitosan (CS) blend nanofibers from their solutions. The effect of blend ratios (PVA/CS: 1%, 3%, 5%, and 7% (w/w)), applied voltage, and flow rate on the morphological, optical, and thermal properties of electrospun nanofibers were investigated by scanning electron microscopy (SEM), fluorescence and UV-Vis spectroscopies, and thermogravimetric analysis (TGA), respectively. Fourier transform infrared spectroscopy analysis indicated the existence of related functional groups of both PVA and CS in the electrospun fibers. During the electrospinning process, the maximum possible ratio of CS was 7% (w/w). SEM images indicated that …


Efficient Synthesis And Antifungal Investigation Of Nucleosides' Quaternary Ammonium Salt Derivatives, Barbara Dmochowska, Lucyna Pellowska-Januszek, Justyna Samaszko-Fiertek, Rafal Slusarz, Roland Wakiec, Janusz Madaj Jan 2019

Efficient Synthesis And Antifungal Investigation Of Nucleosides' Quaternary Ammonium Salt Derivatives, Barbara Dmochowska, Lucyna Pellowska-Januszek, Justyna Samaszko-Fiertek, Rafal Slusarz, Roland Wakiec, Janusz Madaj

Turkish Journal of Chemistry

Quaternary ammonium salts are a group of compounds with diverse biological properties, the most important of which are their antiviral, antibacterial, and antifungal activities. The quaternization reactions of 5'-$O$-tosyl derivatives of uridine and thymidine with triethylamine, trimethylamine, 4-($N$,$N$-dimethylamino)pyridine, 2-methylpyridine, and pyridine are described in this article. Two of the synthesized compounds are exceptional because they are first of this type that demonstrate concentration-dependent antifungal in vitro activity against two species of the genus Candida in minimal YNB-SG medium. The experimental results have been extended by adding full atom molecular dynamics simulations and substrates and products energies evaluation.


Plasma O$_{2}$ Modifies The Structure Of Synthetic Zeolite-A To Improve The Removal Of Cadmium Ions From Aqueous Solutions, Alaa Fahmy, Ahmed Elzaref, Hanan Youssef, Hassan Shehata, Magdy Wassel, Jörg Friedrich, Fabienne Poncin-Epaillard, Dominique Debarnot Jan 2019

Plasma O$_{2}$ Modifies The Structure Of Synthetic Zeolite-A To Improve The Removal Of Cadmium Ions From Aqueous Solutions, Alaa Fahmy, Ahmed Elzaref, Hanan Youssef, Hassan Shehata, Magdy Wassel, Jörg Friedrich, Fabienne Poncin-Epaillard, Dominique Debarnot

Turkish Journal of Chemistry

The present study addresses the removal of cadmium ions (Cd(II)) from aqueous solutions at a pH of 7.5 using zeolite-A activated by exposure to oxygen plasma. The activation process was performed over a wide range of plasma powers (10, 20, 30, and 40 W) and exposure times (30 to 360 s). Oxygen plasma cannot chemically modify zeolite to a considerable extent, but it can clean the surface, open blocked pores, and induce the formation of additional OH groups via exposure to humidity in ambient air. Therefore, Cd$^{+2}$ ion removal is increased by approximately 10% with the plasma treatments. Infrared-attenuated total …


Crystal Structure And Hirshfeld Surface Analysis Of 1,2-Ethylene-Bis (Para-Methyl Pyridinium) Dichromate As A New Selective And Mild Agent In Oxidation Of Alcohols, Mostafa Gholizadeh, Mehrdad Pourayoubi, Mohammad Reza Houssiendokht, Hadi Amiri Rudbari, Masoumeh Farimaneh, Anahid Saneei, Giuseppe Bruno Jan 2019

Crystal Structure And Hirshfeld Surface Analysis Of 1,2-Ethylene-Bis (Para-Methyl Pyridinium) Dichromate As A New Selective And Mild Agent In Oxidation Of Alcohols, Mostafa Gholizadeh, Mehrdad Pourayoubi, Mohammad Reza Houssiendokht, Hadi Amiri Rudbari, Masoumeh Farimaneh, Anahid Saneei, Giuseppe Bruno

Turkish Journal of Chemistry

1,2-Ethylene-bis(para-methyl pyridinium) dichromate, (C$_{14}$H$_{18}$N$_{2})$[Cr$_{2}$O$_{7}$], is used as a new oxidizing agent in conversion of some alcohols to their corresponding carbonyl compounds in CH$_{3}$CN solvent and also under solvent-free conditions. In both procedures, high conversion percentages are observed. However, a much shorter reaction time is achieved in solvent-free conditions. For allylic alcohols, the C=C bond is not oxidized and the examined saturated alcohol in this work (i.e. cyclo-hexanol) remains intact, which illustrates the mild nature of reagent used. The structure of the reagent is investigated by single-crystal X-ray diffraction analysis. The C--H$\cdots$O and O$\cdots \pi$ interactions are the most important features …


New Diazo-Containing Phenolic Oximes: Structural Characterization, Computational Studies, And Solvent Extraction Of Cu(Ii), Ni(Ii), And Zn(Ii) Ions, Muharrem Karabörk, Hi̇lal Kirpik, Koray Sayin, Muhammet Köse Jan 2019

New Diazo-Containing Phenolic Oximes: Structural Characterization, Computational Studies, And Solvent Extraction Of Cu(Ii), Ni(Ii), And Zn(Ii) Ions, Muharrem Karabörk, Hi̇lal Kirpik, Koray Sayin, Muhammet Köse

Turkish Journal of Chemistry

In the current study, four new phenolic oxime ligands (HL1ox-HL4ox) containing diazo groups (-N$=$N-) were synthesized and used for liquid-liquid extraction of heavy metal ions [Cu(II), Ni(II), and Zn(II)]. The new compounds were characterized by analytical and spectroscopic methods. Solid-state structures of HL1ox-HL3ox were determined by single-crystal X-ray diffraction studies. Hirshfeld surface analysis of the compounds was performed to determine the contribution of different intermolecular contacts to the stability of the structures. The HL1ox-HL4ox ligands showed higher extraction performance for Cu(II) ion than Ni(II) and Zn(II) ions. The effect of pH on extraction capacity was investigated and the oxime compounds …


In Situ Preparation Of Hydroxyapatite Composites Into Hydrolyzed Polyacrylamide Solution And Methylene Blue Dye Retention, Ali Mansri, Hanane Mahroug, Faycal Dergal Jan 2019

In Situ Preparation Of Hydroxyapatite Composites Into Hydrolyzed Polyacrylamide Solution And Methylene Blue Dye Retention, Ali Mansri, Hanane Mahroug, Faycal Dergal

Turkish Journal of Chemistry

Four composites of hydroxyapatite/hydrolyzed polyacrylamide (HAP/HPAM-n) were prepared using an in situ wet chemical method. The synthesis was performed by preparing a suspension of calcium in a copolymer solution having a known HPAM concentration. Phosphoric acid was added dropwise to each suspension to obtain HAP/HPAM-n composites. The effect of initial copolymer amount on the composite properties was investigated using XRD, FTIR, TGA, and SEM/EDS analysis. The obtained results were compared to the HAP sample synthesized under the same conditions and without copolymer. HPAM amount in the composite affects the retention of methylene blue (MB) dye. The result shows that the …


Characterization And Purification Of 1,2,4-Triazole-Containing Phthalocyanines Synthesized By Microwave Method And Structure Elucidation By Spectroscopic Techniques, Asi̇ye Nas, Ümi̇t Demi̇rbaş, Nurhan Gümrükçüoğlu, Hali̇t Kanteki̇n Jan 2019

Characterization And Purification Of 1,2,4-Triazole-Containing Phthalocyanines Synthesized By Microwave Method And Structure Elucidation By Spectroscopic Techniques, Asi̇ye Nas, Ümi̇t Demi̇rbaş, Nurhan Gümrükçüoğlu, Hali̇t Kanteki̇n

Turkish Journal of Chemistry

The complexes of peripherally tetra-substituted metal-free (8), lead(II) 9), and zinc(II) (10) phthalocyanine derivatives were synthesized for the first time in this work. The structures of these new complex compounds have been elucidated using many spectral methods such as electronic absorption, FT-IR, $^{1}$H NMR, $^{13}$C NMR, elemental analysis, and mass spectra. The thermogravimetric behavior of compounds 8-10 was determined by thermogravimetric analysis method in addition to these spectral methods.


Rapid And On-Site Electrochemical Detection Of Bisphenol A And Arsenic In Drinking Water Using A Novel Electrode Array, Yildiz Uludağ, Zehra Ölçer, Canan Doğan, Turghun Muhammad, Zeynep Altintaş Jan 2019

Rapid And On-Site Electrochemical Detection Of Bisphenol A And Arsenic In Drinking Water Using A Novel Electrode Array, Yildiz Uludağ, Zehra Ölçer, Canan Doğan, Turghun Muhammad, Zeynep Altintaş

Turkish Journal of Chemistry

The paper describes a novel dip-and-gauge hand-held sensor device for the rapid, cost-effective, and on-site detection of bisphenol A and arsenic in drinking water samples. Different working electrode diameters ranging from 1.5 mm to 4 mm were designed and fabricated to construct a new electrochemical biosensor. The sensor was employed for the chronoamperometric detection of bisphenol A and voltammetric determination of arsenic in drinking water samples. Bisphenol A measurements resulted in a detection limit of 10 ng mL$^{-1}$ with a linear range of 0-4000 ng mL$^{-1}$. Baby products and bottles have to be completely free of bisphenol and hence a …


Investigation Of The Structural And Physicochemical Requirements Of Quinoline-Arylamidine Hybrids For The Growth Inhibition Of K562 And Raji Leukemia Cells, Vesna Rastija, Marijana Jukic, Teuta Opacak-Bernardi, Luka Krstulovic, Ivana Stolic, Ljubica Glavac-Obrovac, Miroslav Bajic Jan 2019

Investigation Of The Structural And Physicochemical Requirements Of Quinoline-Arylamidine Hybrids For The Growth Inhibition Of K562 And Raji Leukemia Cells, Vesna Rastija, Marijana Jukic, Teuta Opacak-Bernardi, Luka Krstulovic, Ivana Stolic, Ljubica Glavac-Obrovac, Miroslav Bajic

Turkish Journal of Chemistry

Quantitative structure-activity relationship (QSAR) analysis of 28 quinoline-arylamidine (CQArA) hybrids against two leukemia cells, K562 and Raji, was performed. Multiple linear regression (MLR) models were obtained by genetic algorithm. The best models involved the following descriptors: radial distribution function (RDF) descriptors, GETAWAY (GEometry, Topology, and Atom-Weights AssemblY) descriptor, bond information content index, and dipole moment. The best MLR models for K562 and Raji cells demonstrated satisfactory stability in internal and external validation. Since the QSAR model for Raji cells has better predictive ability, two new highly potent CQArA analogues were proposed based on it. The QSAR models revealed important physicochemical …


3d-Qsar/Hqsar-Based Analysis Of Bioconcentration And Molecular Modification Of Monophenyl Aromatic Compounds, Qing Li, Wenwen Gu, Yu Li Jan 2019

3d-Qsar/Hqsar-Based Analysis Of Bioconcentration And Molecular Modification Of Monophenyl Aromatic Compounds, Qing Li, Wenwen Gu, Yu Li

Turkish Journal of Chemistry

Comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) of three-dimensional quantitative structure-activity relationship (3D-QSAR) models were conducted using 36 aromatic compound congeners as the training set and eight aromatic compound congeners as the test set. Logarithms of experimental bioconcentration data (logBCF) were used as dependent variables and the physicochemical properties of the aromatic compound congeners were used as independent variables. Furthermore, the molecular holographic quantitative structure--activity relationship (HQSAR) model constructed by the HQSAR module in Sybyl software was used to establish a method to find molecular activity substitution sites of bioconcentration potential by coupling the molecule …


Synthesis Of Novel Azo Linkage-Based Schiff Bases Including Anthranilic Acid And Hexanoic Acid Moieties: Investigation Of Azo-Hydrazone And Phenol-Keto Tautomerism, Solvatochromism, And Ionochromism, Özlem Özdemi̇r Jan 2019

Synthesis Of Novel Azo Linkage-Based Schiff Bases Including Anthranilic Acid And Hexanoic Acid Moieties: Investigation Of Azo-Hydrazone And Phenol-Keto Tautomerism, Solvatochromism, And Ionochromism, Özlem Özdemi̇r

Turkish Journal of Chemistry

Two new azo-Schiff base receptors (L$_{{1}}$ and L$_{{2}})$ containing azo and azomethine groups with a conjugated group (benzyl ring of anthranilic acid, in L$_{{1}})$ and electron-donating group (alkyl chain of hexanoic acid, in L$_{{2}})$ were synthesized and characterized. Azo-hydrazone/phenol-keto tautomerism and solvatochromism were investigated. Studying their sensing ability towards cations (Co$^{2+}$, Cu$^{2+}$, Zn$^{2+}$, Ni$^{2+}$, Pb$^{2+}$, Cd$^{2+}$, Mn$^{2+}$, Fe$^{3+}$, Cr$^{3+}$, and Al$^{3+})$, high sensitivity and selectivity were recorded for Fe$^{3+}$ by naked eye and UV-Vis spectra in DMF-aqueous HEPES buffer (v:v, 1:1, pH 6.8). The color of L$_{{1}}$ and L$_{{2}})$ solutions instantly changed from yellow to deep orange and pale orange. …


An Efficient Protocol For The Synthesis Of Brominated Norbornene, Norbornadiene, And Benzonorbornadiene, Selçuk Eşsi̇z Jan 2019

An Efficient Protocol For The Synthesis Of Brominated Norbornene, Norbornadiene, And Benzonorbornadiene, Selçuk Eşsi̇z

Turkish Journal of Chemistry

An efficient protocol for the synthesis of 2-bromonorbornene, 2-bromonorbornadiene, 2-bromoben- zonorbornadiene, 2,3-dibromonorbornene, 2,3-dibromonorbornadiene, and 2,3-dibromobenzonorbornadiene in good yields has been developed. 1,2-Dibromotetrachloroethane is used as the brominating agent for these reactions. The results are discussed in comparison with alternative methods in the literature.


Gold-Assembled Silica-Coated Cobalt Nanoparticles As Efficient Magnetic Separation Units And Surface-Enhanced Raman Scattering Substrate, Lütfi̇ye Sezen Yildirim, Murat Kaya, Mürvet Volkan Jan 2019

Gold-Assembled Silica-Coated Cobalt Nanoparticles As Efficient Magnetic Separation Units And Surface-Enhanced Raman Scattering Substrate, Lütfi̇ye Sezen Yildirim, Murat Kaya, Mürvet Volkan

Turkish Journal of Chemistry

Magnetic and optical bifunctional nanoparticles that combine easy separation, preconcentration, and efficient SERS capabilities have been fabricated with high sensitivity and reproducibility through a low-cost method. These gold nanoparticles attached on magnetic silica-coated cobalt nanospheres (Co@SiO$_{2}$/AuNPs) display the advantage of strong resonance absorption due to gaps at nanoscale between neighboring metal nanoparticles bringing large field enhancements, known as "hot spots". The prepared particles can be controlled by using an external magnetic field, which makes them very promising candidates in biological applications and Raman spectroscopic analysis of dissolved organic species. The magnetic property of the prepared particles lowers the detection limits …


Plasma Polymerized Linalool (Pplin): An Antimicrobial And Biocompatible Coating, Kenan Çakmak, Özkan Bayram, Kübra Solak, Güzi̇n Kaban, Önder Şi̇mşek, Ahmet Mavi̇ Jan 2019

Plasma Polymerized Linalool (Pplin): An Antimicrobial And Biocompatible Coating, Kenan Çakmak, Özkan Bayram, Kübra Solak, Güzi̇n Kaban, Önder Şi̇mşek, Ahmet Mavi̇

Turkish Journal of Chemistry

Bacterial infections in medical devices and drug resistance of bacteria can cause chaos in the world due to loss of lives in addition to the cost of device revisions, quarantine, disinfection of infected areas, and patient treatment. Antibacterial coatings of essential oils on medical devices can prevent bacterial attachment and reduce costs. Linalool is an antibacterial constituent of essential oils. Herein, we examine for the first time the fabrication and characterization of radio frequency (RF) plasma polymerized hydrophilic thin films from linalool (ppLin) by varying deposition parameters (RF power and deposition time) and the behavior of ppLin with two bacteria …


Computational Investigation Of Influenza A Virus M2 Protein Inhibition Mechanism By Ion Channel Blockers, Mehmet Özbi̇l Jan 2019

Computational Investigation Of Influenza A Virus M2 Protein Inhibition Mechanism By Ion Channel Blockers, Mehmet Özbi̇l

Turkish Journal of Chemistry

The M2 protein of the influenza A virus, responsible for flu, is a homotetramer transmembrane protein, forming a transmembrane ion channel, where His 37s act as pH sensors and Trp 41s and Asp 44s act as channel gates. Opening of this channel leads to transfer of virus RNA into the human host. Thus, blocking this transfer is an important pharmaceutical strategy to stop infection. As a result of viral drug resistance, commercially available channel inhibitors, rimantadine (RIM) and amantadine (AMA), are not as effective as they used to be. Understanding binding sites and outcomes of binding will lead to new …


Chemistry Of Endemic \Textit{Tanacetum Mucroniferum} Hub.-Mor. {\&} Grierson Extracts And Three New Sesquiterpene Lactones, Hüseyi̇n Servi̇, Nezhun Gören Jan 2019

Chemistry Of Endemic \Textit{Tanacetum Mucroniferum} Hub.-Mor. {\&} Grierson Extracts And Three New Sesquiterpene Lactones, Hüseyi̇n Servi̇, Nezhun Gören

Turkish Journal of Chemistry

Tanacetum mucroniferum Hub.-Mor. & Grierson was collected from Sakaltutan in Erzincan Province of Turkey. Comparative phytochemical investigation was carried out on the ethyl acetate and methanol extracts of the plant. The secondary metabolites were isolated and purified by chromatographic methods such as column chromatography, medium pressure liquid chromatography, high-performance thin-layer chromatography, and preparative thin-layer chromatography. The extracts of the aerial parts of Tanacetum mucroniferum yielded three new sesquiterpene lactones and some known compounds, namely two sesquiterpene lactones, six flavonoids, three coumarins, and one triterpene. Structures of isolated compounds were determined by IR, UV, $^{1}$H NMR, APT, COSY, HSQC, HMBC, NOESY, …


Preparation Of $\Alpha $-Hydroxyphenylacetic Acid With Cyclodextrins As An Effective Phase-Transfer Catalyst And Its Reaction Mechanism, Bing Ren Tian, Rui Xia Zhang, Hui Min Chu, Qing Huang, Zhi Zhong Wang Jan 2019

Preparation Of $\Alpha $-Hydroxyphenylacetic Acid With Cyclodextrins As An Effective Phase-Transfer Catalyst And Its Reaction Mechanism, Bing Ren Tian, Rui Xia Zhang, Hui Min Chu, Qing Huang, Zhi Zhong Wang

Turkish Journal of Chemistry

An effective procedure for the synthesis of $\alpha $-hydroxyphenylacetic acid with cyclodextrin (CD) catalysts was developed. The phase-transfer catalyst types, catalyst loadings, reaction times, reaction temperatures, and substrate molar ratios were investigated to optimize the reaction conditions. In addition, the factors that affect the reaction were studied, and the relationship between benzaldehyde and $\beta $-cyclodextrin ($\beta $-CD) was analyzed through 2D-ROESY. The equilibrium constant when $\beta $-CD was used as the catalyst was calculated. The results indicated that $\beta $-CD is the optimal catalyst for the reported reaction (yield: 69.08%). Furthermore, the mechanism underlying the reported reaction was proposed.


Progress In The Chemistry Of 3-Amino-9-Ethylcarbazole, Samir Bondock, Salwa Alqahtani, Ahmed M. Fouda Jan 2019

Progress In The Chemistry Of 3-Amino-9-Ethylcarbazole, Samir Bondock, Salwa Alqahtani, Ahmed M. Fouda

Turkish Journal of Chemistry

Generally, 3-amino-9-ethylcarbazole is considered a versatile compound not only for its unique electronic properties but also for its significance as a building block in synthetic, pharmaceutical, and material chemistry. The synthesis, chemical reactivity, and applications of 3-amino-9-ethylcarbazole are described in this review. The presence of the amino group at position 3 exhibits a unique reactivity with both C-2 and C-4. The reactions of 3-amino-9-ethylcarbazole are divided into three categories, reactions that involve the amino group and cyclization reactions that involve the amino group and C-2 and/or C-4. In this review, relevant and appropriate applications of the synthesized, isolated, and condensed …


Why Protein Conformers In Molecular Dynamics Simulations Differ From Their Crystal Structures: A Thermodynamic Insight, Fi̇li̇ppo Pullara, Mao Wenzhi, Mert Gür Jan 2019

Why Protein Conformers In Molecular Dynamics Simulations Differ From Their Crystal Structures: A Thermodynamic Insight, Fi̇li̇ppo Pullara, Mao Wenzhi, Mert Gür

Turkish Journal of Chemistry

Conformers generally deviate structurally from their starting X-ray crystal structures early in molecular dynamics (MD) simulations. Studies have recognized such structural differences and attempted to provide an explanation for and justify the necessity of MD equilibrations. However, a detailed explanation based on fundamental physics and validation on a large ensemble of protein structures is still missing. Here we provide the first thermodynamic insights into the radically different thermodynamic conditions of crystallization solutions and conventional MD simulations. Crystallization solution conditions can lead to nonphysiologically high ion concentrations, low temperatures, and crystal packing with strong specific protein--protein interactions, not present under physiological …


New Flavonoid Glycosides Conjugates: Synthesis, Characterization, And Evaluation Of Their Cytotoxic Activities, Sawssen Souiei, Fatima Bousejra-El Garah, Mohamed Amine Belkacem, Mansour Znati, Jalloul Bouajila, Hichem Ben Jannet Jan 2019

New Flavonoid Glycosides Conjugates: Synthesis, Characterization, And Evaluation Of Their Cytotoxic Activities, Sawssen Souiei, Fatima Bousejra-El Garah, Mohamed Amine Belkacem, Mansour Znati, Jalloul Bouajila, Hichem Ben Jannet

Turkish Journal of Chemistry

A series of novel halogenated 3-hydroxyflavones (3HFs) were prepared by reacting halogenated hydroxyacetophenones with the appropriate aromatic aldehyde. Glycosylation of 3HFs with acetobromoglucose and deprotection of the acetyl protective groups afforded the desired 3-$O$-flavonoids glycosides in satisfactory yields. All the prepared compounds were tested for their cytotoxic activity against HCT-116, MCF-7, and OVCAR-3 human cancer cell lines. The 3HFs exhibited higher cytotoxic activities compared with the glycosylated flavonoids. Overall, the structure-activity relationship study showed that the introduction of glycoside moiety at the C-3 OH position does not improve the bioactivity.


Spectrophotometric Methods For The Determination Of Fluoride Ion Using Indole-3-Acetic Acid Interaction With Iron(Iii), Emi̇ne İlknur Öztürk, Adnan Kenar, Mehmet Levent Aksu, Mustafa Taşteki̇n Jan 2019

Spectrophotometric Methods For The Determination Of Fluoride Ion Using Indole-3-Acetic Acid Interaction With Iron(Iii), Emi̇ne İlknur Öztürk, Adnan Kenar, Mehmet Levent Aksu, Mustafa Taşteki̇n

Turkish Journal of Chemistry

This study is related to the determination of fluoride ion by the conversion of pink-colored Fe(III) and indole-3-acetic acid (IAA) into a colorless hexafluoride ferrite complex with the addition of fluoride. The optimum conditions of the complex formation were found to be pH 1.7 and a temperature of 60 $^{\circ}$C C. The maximum absorption wavelength of the complex and the detection limit of the method were 525 nm and 0.26 mg/L, respectively. The interfering effects of the different cations (Ag$^{+}$, Al$^{3+}$, Ba$^{2+}$, Ca$^{2+}$, Cd$^{2+}$, Co$^{2+}$, Cu$^{2+}$, K$^{+}$, Mg$^{2+}$, Na$^{+}$, Ni$^{2+}$, Pb$^{2+})$ and anions (SO$_{4}^{2-}$, SO$_{3}^{2-}$, NO$_{2}^{-}$, I$^{-}$, Br$^{-}$, Cl$^{-}$, SCN$^{-}$, …


Biodegradability Study Of Polypropylene Fibers Blended With Disposable Recycled Poly(Lactic Acid) Plastic Flakes, Mohammad Ali Tavanaie, Abolfazl Mahmudi Gevari Jan 2019

Biodegradability Study Of Polypropylene Fibers Blended With Disposable Recycled Poly(Lactic Acid) Plastic Flakes, Mohammad Ali Tavanaie, Abolfazl Mahmudi Gevari

Turkish Journal of Chemistry

Polymer blending as an efficient method for blending at least two~polymers is usually used to create new materials with desirable physical properties. This article focuses on the biodegradability evaluation of polypropylene (PP) fibers modified with disposable recycled poly(lactic acid) (r-PLA) plastic flakes. Biodegradable modified PP fibers containing 30% r-PLA were prepared by melt spinning process and evaluated with different methods of biodegradation assays. The soil burial test method, CO$_{2}$ evolution analysis, weight loss, mechanical properties, and average molecular weight measurements and analysis of surface morphological changes were performed for biodegradability evaluation of the modified PP fibers. Surface morphology of the …


Acid-Activated Clay As Heterogeneous And Reusable Catalyst For The Synthesis Of Bioactive Cyclic Ketal Derivatives, Wided Hagui, Rym Essid, Sondes Amri, Nadia Fares, Mohamed Khabbouchi, Olfa Tabbene, Ferid Limam, Ezzedine Srasra, Neji Besbes Jan 2019

Acid-Activated Clay As Heterogeneous And Reusable Catalyst For The Synthesis Of Bioactive Cyclic Ketal Derivatives, Wided Hagui, Rym Essid, Sondes Amri, Nadia Fares, Mohamed Khabbouchi, Olfa Tabbene, Ferid Limam, Ezzedine Srasra, Neji Besbes

Turkish Journal of Chemistry

A new heterogeneous acid catalyst based on a natural resource, Tunisian clay (Clay-H0.5), has been prepared and characterized by FT-IR, FE-SEM, and powder X-ray diffraction (XRD), as well as chemical composition, cation exchange capacity, specific surface area, and pore volume. Acid treatment for 0.5 h enlarged the surface area from 78.24 to 186.10 m$^{2}$/g and pore volume (PV) from 0.186 to 0.281 cm$^{3}$/g. The catalytic activity of this material was investigated in ketalization reaction under mild solvent-free conditions. This achieved up to 92% isolated yield for only 10 wt.% of the catalyst. This environmentally friendly method has advantages such as …


Synthesis And Characterization Of Polycaprolactone-Based Segmented Polyurethanes, Aysun Güney, Aysel Kiziltay, Nesri̇n Hasirci, Tuğba Endoğan Tanir Jan 2019

Synthesis And Characterization Of Polycaprolactone-Based Segmented Polyurethanes, Aysun Güney, Aysel Kiziltay, Nesri̇n Hasirci, Tuğba Endoğan Tanir

Turkish Journal of Chemistry

Segmented polyurethanes were synthesized by the reactions of poly($\varepsilon $-caprolactone) (PCL)-diol and 1,6-hexamethylene diisocyanate through bulk polymerization without using solvent, initiator, or catalyst. Phase separation and hydrogen bond formation between hard segments or between hard and soft segments were examined by Fourier transform infrared spectroscopy (FTIR)-ATR and X-ray diffraction (XRD), while physical and mechanical properties were studied by atomic force microscope, differential scanning calorimeter, dynamic mechanical analysis, and tensile tester. When the diisocyanate content was increased, deconvolution results of FTIR-ATR in C$=$O and N-H regions demonstrated better miscibility of the segments and XRD results showed a significant decrease in the …


Boric Acid As An Efficient And Green Catalyst For The Synthesis Of 2-Amino-4,6-Diarylnicotinonitrile Under Microwave Irradiation In Solvent-Free Conditions, Zahra Hosseinzadeh, Ali Ramazani, Nima Razzaghi-Asl, Katarzyna Slepokura, Tadeusz Lis Jan 2019

Boric Acid As An Efficient And Green Catalyst For The Synthesis Of 2-Amino-4,6-Diarylnicotinonitrile Under Microwave Irradiation In Solvent-Free Conditions, Zahra Hosseinzadeh, Ali Ramazani, Nima Razzaghi-Asl, Katarzyna Slepokura, Tadeusz Lis

Turkish Journal of Chemistry

Microwave irradiation has been used to improve the one-pot synthesis of substituted 2-amino-4,6-diarylnicoti- nonitrile in the presence of boric acid as an efficient and green catalyst under solvent-free conditions within 48--60 s. All the analogs that have not been reported previously were characterized by their melting points, IR, $^{1}$H NMR, and $^{13}$C NMR spectra. One of the structures was verified by the analysis of a single crystal. The reported synthetic procedure provided remarkable advantages such as short reaction times, excellent yield, facile workup, and the use of a green catalyst.


Fuel Characteristics And Combustion Behavior Of Seaweed-Derived Hydrochars, İsmai̇l Cem Kantarli, Mehmet Pala, Yeli̇z Yildirim, Jale Yanik, Maria Helena Abreu Jan 2019

Fuel Characteristics And Combustion Behavior Of Seaweed-Derived Hydrochars, İsmai̇l Cem Kantarli, Mehmet Pala, Yeli̇z Yildirim, Jale Yanik, Maria Helena Abreu

Turkish Journal of Chemistry

In this study, conversion of seaweeds into hydrochars was investigated with the aim of obtaining a renewable energy feedstock. The seaweeds Fucus serratus and Alaria esculenta, and a mixture of seaweeds, mainly consisting of Cystoseria sp$.$ and Laurencia sp$.$, were subjected to hydrothermal carbonization (HTC) in subcritical water at three different temperatures: 200, 225, and 250 $^{\circ}$C. Fuel characteristics and chemical properties of the derived hydrochars were determined using the standard fuel analysis and spectroscopic methods. The combustion behavior of seaweeds and hydrochars was examined via nonisothermal thermogravimetric analysis under air atmosphere. The seaweed-derived hydrochar yields were lower than those …


Removal Of Cr(Vi) From Wastewater Through Glycine Assisted Synthesis Of Tio$_{2}$, Bi̇lsen Kurtteki̇n, Demet Özer, Nurşen Altuntaş Öztaş Jan 2019

Removal Of Cr(Vi) From Wastewater Through Glycine Assisted Synthesis Of Tio$_{2}$, Bi̇lsen Kurtteki̇n, Demet Özer, Nurşen Altuntaş Öztaş

Turkish Journal of Chemistry

In this study, titanium dioxide was synthesized via solution combustion method. Titanium(IV) oxysulfate was used as a titanium source. The fuel type, reaction time, and reaction temperature were tested for optimization. The glycine was set as a suitable fuel. Structural properties of the final product were characterized by p-XRD. Scanning electron microscopy (SEM) and BET techniques were used to examine the morphology. The synthesized products were compared to the commercial TiO$_{2}$ and it was found that the titanium dioxide with the high surface area (63.628 m$^{2}$/g) has been successfully synthesized by solution combustion method with time and energy saving. In …


Investigation Of The Ideal Composition Of Metal Hexacyanocobaltates With High Water Oxidation Catalytic Activity, Ferdi̇ Karadaş Jan 2019

Investigation Of The Ideal Composition Of Metal Hexacyanocobaltates With High Water Oxidation Catalytic Activity, Ferdi̇ Karadaş

Turkish Journal of Chemistry

The electrocatalytic activities of Prussian blue analogues (PBAs) have recently received much attention due to their robustness and efficiency. Considering that PBAs with hexacyanocobaltate building block stand forward among other PBAs, a systematic study on a family of metal hexacyanocobaltates is presented in this study. Metal hexacyanocobaltates (M $=$ Co, Mn, Ni, and Fe) were prepared, characterized, and electrochemical studies were performed. A series of mixed-metal cobalt-iron hexacyanocobaltates has also been studied to determine the ideal composition of a metal hexacyanocobaltate for electrocatalytic water oxidation process. The overall study clearly indicates that cobalt hexacyanocobaltate exhibits the highest electrocatalytic activity among …


Synthesis, Kinetic Study, And Reaction Mechanism: Nucleophilic Substitution Reactions Of Butyl Methyl Chlorophosphate With Substituted Anilines And Deuterated Substituted Anilines In Acetonitrile, Hasi Rani Barai, Md. Mahbubur Rahman, Sang Woo Joo Jan 2019

Synthesis, Kinetic Study, And Reaction Mechanism: Nucleophilic Substitution Reactions Of Butyl Methyl Chlorophosphate With Substituted Anilines And Deuterated Substituted Anilines In Acetonitrile, Hasi Rani Barai, Md. Mahbubur Rahman, Sang Woo Joo

Turkish Journal of Chemistry

This study demonstrated the kinetics of nucleophilic substitution reactions of butyl methyl chlorophosphate (2) with X-anilines (XC$_{6}$H$_{4}$NH$_{2})$ and deuterated X-anilines (XC$_{6}$H$_{4}$ND$_{2})$ in MeCN at 55.0 \textpm\ 0.1 \textdegree C together with the general optimized method for the synthesis of 2 under mild conditions. Different spectroscopic characterizations revealed the formation of 2 with high purity. The free energy relationship with the substituents X in the anilines exhibited biphasic concavity upwards with a break point at X $=$ H, which induced large negative $\rho_{X}$ and small positive $\beta_{X}$ values. The deuterium kinetic isotope effects (DKIEs) were secondary inverse ($k_{H}$/$k_{D}$ \textless\ 1: 0.702--0.918) …


Pore Length- And Ion Concentration-Dependent Ionic Current In Cylindrical Nanopores: An Atomistic Molecular Dynamics Study, Nazar İleri̇ Ercan Jan 2019

Pore Length- And Ion Concentration-Dependent Ionic Current In Cylindrical Nanopores: An Atomistic Molecular Dynamics Study, Nazar İleri̇ Ercan

Turkish Journal of Chemistry

The sensing of individual molecules as they pass through nanopores under an external field is a popular research field. The approach is simply based on the detectable temporary blockades in the ionic current as the molecules pass through the nanopores. These signatures of the current have been shown to be a function of nanoparticle and nanopore size and geometry as well as the external electric field. However, models developed in this context fail to predict the experimentally observed behavior in technologically important shorter nanopores. Here we present atomistic molecular dynamics simulation results from colloidal nanoparticle translocation through mid-to-low aspect ratio …