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Full-Text Articles in Physical Sciences and Mathematics

Modification Of Biomass-Derived Activated Carbon With Magnetic $\Alpha $-Fe$_{2}$O$_{3}$ Nanoparticles For Co$_{2}$ And Ch$_{4}$ Adsorption, Çi̇sem Kirbiyik Jan 2019

Modification Of Biomass-Derived Activated Carbon With Magnetic $\Alpha $-Fe$_{2}$O$_{3}$ Nanoparticles For Co$_{2}$ And Ch$_{4}$ Adsorption, Çi̇sem Kirbiyik

Turkish Journal of Chemistry

Magnetic and nonmagnetic activated carbons (ACs) were successfully prepared by using AC obtained from spent coffee grounds (SCGs) for use in CO$_{2}$ and CH$_{4}$ capture. SCGs were activated by chemical activation to produce ACs and a magnetic $\alpha $-Fe$_{2}$O$_{3}$/AC composite was prepared by coprecipitation method from the ACs produced. Magnetic and nonmagnetic samples were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and energy dispersive X-ray spectrometry (EDX) techniques. The textural properties of samples were determined by nitrogen adsorption-desorption using the Brunauer--Emmett--Teller (BET) and Barrett--Joyner--Halenda (BJH) methods. The results showed that the porosity of …


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 …


Enhanced Uptake Capacities And Isosteric Heats Of Co$_{2}$ And Ch$_{4}$ Adsorption On Spent Coffee Ground Activated Carbons Loaded With Metal Ions, Çi̇sem Kirbiyik, Burak Zafer Büyükbekar, Mahmut Kuş, Mustafa Ersöz Jan 2019

Enhanced Uptake Capacities And Isosteric Heats Of Co$_{2}$ And Ch$_{4}$ Adsorption On Spent Coffee Ground Activated Carbons Loaded With Metal Ions, Çi̇sem Kirbiyik, Burak Zafer Büyükbekar, Mahmut Kuş, Mustafa Ersöz

Turkish Journal of Chemistry

Low-cost activated carbon (AC) samples obtained from waste coffee grounds were used for CO$_{2}$ and CH$_{4}$ adsorption. ACs were prepared by chemical activation and carbonized at three different temperatures. AC carbonized at 800 $^{\circ}$C showed a relatively high surface area (582.92 m$^{2}$ g$^{-1})$ and high adsorption capacities of 2.6 mmol g$^{-1}$ and 1.1 mmol g$^{-1}$ at 25 $^{\circ}$C for CO$_{2}$ and CH$_{4}$, respectively. Adsorbent samples were prepared by loading of Fe$^{3+}$ metal ions onto ACs and their adsorption capacities were compared with those of nonloaded ACs. As expected, the loading of Fe$^{3+}$ metal ions increased the adsorption capacities at all …


Synthesis, Characterization, And Kinetic Studies Of Multifunctionalized Mesoporous Silica For Adsorption Of Zinc, Ali̇me Çitak Jan 2019

Synthesis, Characterization, And Kinetic Studies Of Multifunctionalized Mesoporous Silica For Adsorption Of Zinc, Ali̇me Çitak

Turkish Journal of Chemistry

The aim of this study is to evaluate the utilization of bifunctional mesoporous silica with a platinum and propylsulfonic acid group (Pt/SBA15-PrSO$_{3}$H) as an adsorbent for the removal of Zn(II) ions from aqueous solutions. The SBA15-functionalized organosulfonic acid material was synthesized with a one-step cocondensation synthesis route. The second step was Pt loading during reduction and deposition into the aqueous suspension of the bifunctional mesoporous silica synthesized by an aqueous solution of formaldehyde as the reducing agent. The propylsulfonic acid and platinum functionalized mesoporous silica were characterized by BET, thermogravimetric analysis, and X-ray diffraction methods. The adsorption properties and thermodynamic …


An Insight Into The Therapeutic Potential Of Piperazine-Based Anticancer Agents, Kamran Walayat, Noor Ul Amin Mohsin, Sana Aslam, Matloob Ahmad Jan 2019

An Insight Into The Therapeutic Potential Of Piperazine-Based Anticancer Agents, Kamran Walayat, Noor Ul Amin Mohsin, Sana Aslam, Matloob Ahmad

Turkish Journal of Chemistry

The piperazine ring system is among the medicinally important nitrogen-containing heterocyclic ring systems and is exploited for the synthesis of various drug molecules. A number of FDA-approved anticancer drugs contain piperazine rings and thus it is considered as an attractive scaffold having extraordinary potential for the development of new anticancer agents. In recent decades there has been an alarming increase in the number of people suffering from cancerous diseases all over the world, which resulted in an extraordinary increase in research reports on new anticancer drug candidates. The aim of this article is to highlight the structural parameters imparting anticancer …


Preparation And Physicochemical Characterization Of Zinc Oxide/Sodium Cellulose Composite For Food Packaging, Sherif Mohamed Abdel Salam Keshk, Mohamed Saad Hamdy Jan 2019

Preparation And Physicochemical Characterization Of Zinc Oxide/Sodium Cellulose Composite For Food Packaging, Sherif Mohamed Abdel Salam Keshk, Mohamed Saad Hamdy

Turkish Journal of Chemistry

Zinc oxide/sodium cellulose composite with different ZnO loadings was prepared for the first time. The crystal structures of cellulose, sodium cellulose, and ZnO/sodium cellulose composite were characterized by FT-IR, XRD, XPS, SEM, and EDX. ZnO/sodium cellulose showed a similar XRD pattern to that of cellulose II. The XPS spectrum emphasized the presence of Zn$^{2+}$ and Na$^{+\, }$ ions in the prepared composite. Additionally, the SEM analysis showed the growth of ZnO crystals on the sodium cellulose surface. UV-Vis spectrometry of the ZnO/sodium cellulose spectrum showed a distinguished absorption band at 360 nm that was attributed to the presence of ZnO …


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 …


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 …


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 …


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 …


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.


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 …


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) …


Synthesis, Crystal Structure, And Characterization Of Two Heterometallic Transition Metal Citrate Complexes [M $=$ Co(Ii) And Cd(Ii)], Zeki̇ Kartal, Onur Şahi̇n, Abdülkeri̇m Yavuz Jan 2019

Synthesis, Crystal Structure, And Characterization Of Two Heterometallic Transition Metal Citrate Complexes [M $=$ Co(Ii) And Cd(Ii)], Zeki̇ Kartal, Onur Şahi̇n, Abdülkeri̇m Yavuz

Turkish Journal of Chemistry

In this study, two heterometallic transition metal complexes with the formulas [CoK$_{4}(\mu _{10}$-C$_{6}$H$_{5}$O$_{7})_{2}$]$_{n}$ and [CdK($\mu _{8}$-C$_{6}$H$_{5}$O$_{7})(\mu $-H$_{2}$O)(H$_{2}$O)]$_{n}$ were synthesized as crystalline compounds. The structures of\textbf{ }these crystalline metal complexes were characterized by their spectral analyses (FT-IR, FT-Raman, thermal analysis, magnetic properties, and single-crystal X-ray diffraction techniques). According to the spectral data of the new metal complexes obtained, both metal complexes are in the monoclinic crystal system and in the P2$_{1}$/c and P2$_{1}$ space groups, respectively. The asymmetric unit of the metal complex [CoK$_{4}(\mu _{10}$-C$_{6}$H$_{5}$O$_{7})_{2}$]$_{n}$ contains one Co(II) ion, two potassium cations, and one (C$_{6}$H$_{5}$O$_{7})$ citrate ligand, whereas that of the …


Preparation Of Epoxidized Sunflower Oil Metal Soap Derivatives And Their Use As Heat Stabilizers For Polyvinyl Chloride, Ouassila Chelil, Naima Belhaneche-Bensemra, Daniel Lopez Garcia, Marta Fernandez-Garcia, Mohamed Tahar Benaniba Jan 2019

Preparation Of Epoxidized Sunflower Oil Metal Soap Derivatives And Their Use As Heat Stabilizers For Polyvinyl Chloride, Ouassila Chelil, Naima Belhaneche-Bensemra, Daniel Lopez Garcia, Marta Fernandez-Garcia, Mohamed Tahar Benaniba

Turkish Journal of Chemistry

The aim of this work was to prepare metal soaps of epoxidized sunflower oil (ESO) and use them as thermal stabilizers for polyvinyl chloride (PVC). For that purpose, commercial sunflower oil was first epoxidized and then used to prepare (Ba, Zn, Pb, and Cd) metal soap derivatives, which were characterized by Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The prepared metal soaps derivatives of ESO were used as thermal stabilizers for plasticized PVC. Discoloration, residual thermal stability at 200 $^{\circ}$C , and rheological properties of PVC samples were tested. The structural modifications were investigated …


Chiral 1,4-Aminoalkylphenols For Enantioselective Diethylzinc Addition To Aldehydes, Ömer Di̇lek, Mustafa Ali̇ Tezeren, Tahi̇r Ti̇lki̇, Erkan Ertürk Jan 2019

Chiral 1,4-Aminoalkylphenols For Enantioselective Diethylzinc Addition To Aldehydes, Ömer Di̇lek, Mustafa Ali̇ Tezeren, Tahi̇r Ti̇lki̇, Erkan Ertürk

Turkish Journal of Chemistry

Starting from a chiral secondary alcohol, novel enantiopure 1,4-aminoalkylphenols (AAPs) were prepared by exploiting conventional organic transformations such as the Mitsunobu reaction, Eschweiler--Clarke N-methylation, and demethylation of anisoles. The catalytic activity of the 1,4-AAPs was investigated in enantioselective Et$_{2}$Zn addition to benzaldehyde. They were found to accelerate the Et$_{2}$Zn addition to benzaldehyde. High yields and enantioselectivities (e.g., 95% yield and 82% ee) were achieved.


An Exploration Of New Avenues Regarding Deep Tissue Penetration And Higher Singlet Oxygen Efficiencies: Novel Near-Ir Photosensitizers For Photodynamic Therapy, Ni̇sa Yeşi̇lgül, Bi̇lal Kiliç Jan 2019

An Exploration Of New Avenues Regarding Deep Tissue Penetration And Higher Singlet Oxygen Efficiencies: Novel Near-Ir Photosensitizers For Photodynamic Therapy, Ni̇sa Yeşi̇lgül, Bi̇lal Kiliç

Turkish Journal of Chemistry

A series of novel BODIPY-bearing electron-withdrawing groups at the meso position are reported here. According to the optical measurements, it may be clearly seen that the introduction of electron-donating groups into 3,5-positions and the presence of electron-withdrawing groups at the meso position of the BODIPY core resulted in spectacular bathochromic shifts (up to ∼ 304 nm), and the projected photosensitizers had absorption bands in the therapeutic window of the electromagnetic spectrum (600-900 nm). The absorption maxima of compounds 4,5,6, and 7 were at 886 nm, 890 nm, 760 nm, and 761 nm, respectively. The singlet oxygen generation experiments revealed that …


The Effect Of Washing On Stabilized And Unstabilized Low-Density Polyethylene Films Naturally Weathered In A Sub-Saharan Region (Ghardaia, Algeria, Souad Behissa, Salem Fouad Chabira, Nourelhouda Benmiloud, Mohamed Sebaa Jan 2019

The Effect Of Washing On Stabilized And Unstabilized Low-Density Polyethylene Films Naturally Weathered In A Sub-Saharan Region (Ghardaia, Algeria, Souad Behissa, Salem Fouad Chabira, Nourelhouda Benmiloud, Mohamed Sebaa

Turkish Journal of Chemistry

The effect of washing stabilized and unstabilized blown extruded films of low-density polyethylene (LDPE) used for greenhouse coverings naturally weathered in a sub-Saharan facility at Ghardaia (Algeria) for 19 and 6 months, respectively, was studied. A comparison between unwashed and daily washed samples was done. The changes in the films' properties were followed at regular intervals using various characterization methods (physicochemical and mechanical). Although in both cases the chemical species formed due to the weathering were qualitatively the same, they essentially differed in their concentrations, namely they were higher for the washed samples than for the unwashed ones. Inversely, the …


Intermolecular Complexes Of Halocyclopropenone Derivatives With The Hypohalous Acids Hof, Hocl, Hobr, And Hoi, Dariush Mirzaei, Abedien Zabardasti, Yaghoub Mansourpanah Jan 2019

Intermolecular Complexes Of Halocyclopropenone Derivatives With The Hypohalous Acids Hof, Hocl, Hobr, And Hoi, Dariush Mirzaei, Abedien Zabardasti, Yaghoub Mansourpanah

Turkish Journal of Chemistry

The intermolecular interactions between halocyclopropenone derivatives (HC$_{3}$OX; X $=$ I, Br, Cl, and F) and hypohalous acids (HOY; Y $=$ I, Br, Cl, and F) were studied via the MP2 method utilizing the aug-cc-pVTZ and aug-cc-pVTZ(-PP) basis sets. The three types of complexes were hydrogen bonds, halogen bonds, and complexes containing both hydrogen and halogen bonds. The results obtained indicated that interactions in the Type 1 complexes were stronger than those in Types 2 and 3. The H-O bonds revealed red shifts with complex formation in Types 1 and 2. The O-Y bonds displayed red shifts in the Type 3 …


Synthesis And Antimicrobial Activity Of 1-(Benzo[B]Thiophen-4-Yl)-4-(2-(Oxo, Hydroxyl, And Fluoro)-2-Phenylethyl)Piperazine And 1-(Benzo[D]Isothiazole-3-Yl)-4-(2-(Oxo, Hydroxy, And Fluoro)-2-Phenylethyl)Piperazine Derivatives, Vaibhav Mishra, Tejpal Singh Chundawat Jan 2019

Synthesis And Antimicrobial Activity Of 1-(Benzo[B]Thiophen-4-Yl)-4-(2-(Oxo, Hydroxyl, And Fluoro)-2-Phenylethyl)Piperazine And 1-(Benzo[D]Isothiazole-3-Yl)-4-(2-(Oxo, Hydroxy, And Fluoro)-2-Phenylethyl)Piperazine Derivatives, Vaibhav Mishra, Tejpal Singh Chundawat

Turkish Journal of Chemistry

Twenty-two compounds in a series of 1-(benzo[$b$]thiophen-4-yl)-4-(2-(oxo, hydroxy, and fluoro)-2-phenylethyl) piperazine and 1-(benzo[$d$]isothiazole-3-yl)-4-(2-(oxo, hydroxy, and fluoro)-2-phenylethyl)-piperazine derivatives were synthesized through nucleophilic substitution reaction of phenacyl bromides with hetero arylpiperazine, reduction, and then fluorination. Compound K2 showed potent activity against gram-negative bacterial stain P. aeruginosa with minimum inhibitory concentration (MIC) value of 12.5 μg/mL. This compound showed better inhibitory activity than the standard drug chloramphenicol. K4 against S. aureus, H2 against P. aeruginosa, and F4 against E. coli showed good inhibitory activity with MIC values of 62.5 μg/mL. Compounds K1, K2, K4, K8, F1, and F3 showed good inhibitory activity against …


Effect Of Fe Substitution On The Partial Oxidation Of Methane To Syngas Over La$_{0.7}$Sr$_{0.3}$Co$_{1-Y}$Fe$_{Y}$O$_{3-\Delta}$ Perovskites, Adilah Aliyatulmuna, Perry Burhan, Bambang Prijamboedi, Hamzah Fansuri, Irmina Kris Murwani Jan 2019

Effect Of Fe Substitution On The Partial Oxidation Of Methane To Syngas Over La$_{0.7}$Sr$_{0.3}$Co$_{1-Y}$Fe$_{Y}$O$_{3-\Delta}$ Perovskites, Adilah Aliyatulmuna, Perry Burhan, Bambang Prijamboedi, Hamzah Fansuri, Irmina Kris Murwani

Turkish Journal of Chemistry

In this research, a series of La$_{0.7}$Sr$_{0.3}$Co$_{1-y}$Fe$_{y}$O$_{3-\delta }$ ($y =$ 0.0--0.4) was successfully synthesized by a solid-state reaction method and syngas production studies were performed using gas chromatography. Thermogravimetric analysis characterized the concentration of Fe$^{3+}$, which gave a low H$_{2}$/CO ratio over La$_{0.7}$Sr$_{0.3}$Co$_{1-y}$Fe$_{y}$O$_{3-\delta }$ without the presence of molecular oxygen. All samples possessed a purely rhombohedral structure. The incorporation of more Fe increased the lattice parameter and changed XRD peaks of the La$_{1-x}$Sr$_{x}$Co$_{0.8}$Fe$_{0.2}$O$_{3}$ from sharp and single to double. Among the catalyst powders tested for syngas production activity, La$_{0.7}$Sr$_{0.3}$Co$_{0.6}$Fe$_{0.4}$O$_{3-\delta }$ ($y =$ 0.4) had the low molar ratio of H$_{2}$/CO …


Improvement Of The Mechanical And Thermal Properties Of Polyester Nonwoven Fabrics By Ptfe Coating, Fatemeh Ashrafi, Mohammad Reza Babaei Lavasani Jan 2019

Improvement Of The Mechanical And Thermal Properties Of Polyester Nonwoven Fabrics By Ptfe Coating, Fatemeh Ashrafi, Mohammad Reza Babaei Lavasani

Turkish Journal of Chemistry

Polyester (polyethylene terephthalate) is one of the most widely used polymers in textiles. Despite all the advantages of this polymer, its low thermal resistance limits its use in filters and protective textiles. On the other hand, polyester nonwovens are used in many products as wipes, filters, and padding. The surface properties of polyester nonwovens are often not perfect for a specific application and need to be modified. Different ways, including coating, have been developed to modify their surface properties. Therefore, in the present study attempts were made to investigate the improvement of the thermal resistance of a polyester nonwoven by …


Tribological Behavior And Quantum Chemical Calculations Of Protic Ionic Liquids: Synthesis, Spectroscopic, And Thermal Properties, Ahmet Karadağ, Hüseyi̇n Akbaş, Duran Karakaş, Kadi̇r Ci̇han Teki̇n, Erdem Korkmazer Jan 2019

Tribological Behavior And Quantum Chemical Calculations Of Protic Ionic Liquids: Synthesis, Spectroscopic, And Thermal Properties, Ahmet Karadağ, Hüseyi̇n Akbaş, Duran Karakaş, Kadi̇r Ci̇han Teki̇n, Erdem Korkmazer

Turkish Journal of Chemistry

Protic ionic liquids (PILs) were synthesized through a stoichiometric neutralization reaction between 2,2$' $-(ethylenedioxy)-bis(ethylamine) { Edbea} and various acids (formic, acetic, boric, decanoic, and gentisic acid). The PILs were characterized by elemental analyses, FTIR, $^{1}$H and $^{13}$C NMR spectroscopy, and thermogravimetric analysis. All the PILs except PIL3 were liquid at room temperature. The viscosity of the PILs (PIL1, 2, 4, 5) was measured using a cone-and-plate viscometer at ambient temperature. Quantum chemical calculations were used to explain the cation/anion ratio in the PILs. Reaction energies in the gas phase calculated at M062X/6-311$+$G(d,p) level were used to determine the cation/anion ratio. …


Sustainable Process For The Production Of Symmetrical Dibasic Acid Ester-Based Thermal Energy Storage Materials From Lipids, Ayhan Yildirim, Kaan Kiraylar Jan 2019

Sustainable Process For The Production Of Symmetrical Dibasic Acid Ester-Based Thermal Energy Storage Materials From Lipids, Ayhan Yildirim, Kaan Kiraylar

Turkish Journal of Chemistry

Oleochemical-based long-chain diesters are potential organic phase change materials convenient for thermal energy storage. The development of efficient and green methods is an important requirement for the preparation of these environmentally friendly compounds, which also are finding wide industrial application. Thus, in the present work, a series of dibasic acid esters were synthesized through ionic liquid catalyzed scalable chemical esterification or transesterification reactions in a solvent-free medium. The starting compounds, dicarboxylic acids or their methyl esters and fatty alcohols or cholesterol, were reacted in the ratio of 1:2 respectively and the synthesized esters were characterized by FT-IR, $^{1}$H NMR, and …


Methyl-Substituted 2-Aminothiazole--Based Cobalt(Ii) And Silver(I) Complexes: Synthesis, X-Ray Structures, And Biological Activities, Ezzat Khan, Tufail Ahmad, Zarif Gul, Farhat Ullah, Muhammad Nawaz Tahir, Awal Noor Jan 2019

Methyl-Substituted 2-Aminothiazole--Based Cobalt(Ii) And Silver(I) Complexes: Synthesis, X-Ray Structures, And Biological Activities, Ezzat Khan, Tufail Ahmad, Zarif Gul, Farhat Ullah, Muhammad Nawaz Tahir, Awal Noor

Turkish Journal of Chemistry

2-Aminothiazole derivatives bear three nucleophilic centers, i.e. endocyclic N, exocyclic NH$_{2}$, and S atom in the ring system. In addition to these centers there are $\pi$-electrons in the ring system which can also expectedly be involved in some sort of coordination. To the best of our knowledge the solid state coordination chemistry of such ligands has not been fully presented in the literature. These ligands (2-amino-4-methylthiazole and 2-amino-5-methylthiazole) were coupled with CoCl$_{2}$ under aerobic conditions to form tetrahedral complexes, bis(2-amino-4-methylthiazole)dichlorocobalt(II) (1) and bis(2-amino-5-methylthiazole)dichlorocobalt(II) (2). Reaction of 2-amino-5-methylthiazole with AgNO$_{3}$ led to an expected two-coordinated, bis(2-amino-5-methylthiazole)silver(I) nitrate (3) as crystalline material. …


Protonation Behavior Of Dextran Amino Acid Esters, Konrad Hotzel, Lidjia Fras Zemljic, Matej Bracic, Thomas Heinze Jan 2019

Protonation Behavior Of Dextran Amino Acid Esters, Konrad Hotzel, Lidjia Fras Zemljic, Matej Bracic, Thomas Heinze

Turkish Journal of Chemistry

Dextran esters of different amino acids (glycine, $\beta $-alanine, L-ornithine, L-lysine) are investigated regarding their pK$_{a}$ values by potentiometric titration. The pK$_{a}$ values of the dextran derivatives are generally dependent on the position of the amino group in relation to the ester group, i.e. the nearer they are located in the molecule, the lower the resulting pK$_{a}$ values are, L-ornithine ester being the exception. An influence of the polymer backbone is ruled out. Stability against hydrolysis at different pH values and over longer periods at constant pH value is measured by potentiometric and polyelectrolyte titration. The $\beta $-alanine ester shows …


Parameterization, Kinetics, And Adsorption Isotherm Of Electrocoagulation Process Of Bromothymol Blue In Aqueous Medium Using Aluminum Electrodes, Okon Abakedi, Victor Mkpenie, John Okafor Jan 2019

Parameterization, Kinetics, And Adsorption Isotherm Of Electrocoagulation Process Of Bromothymol Blue In Aqueous Medium Using Aluminum Electrodes, Okon Abakedi, Victor Mkpenie, John Okafor

Turkish Journal of Chemistry

The removal of bromothymol blue (BTB) from aqueous solution was studied by electrocoagulation (EC) technique using aluminum electrodes. The various experimental conditions known to influence the EC process were parameterized, including the effects of temperature, concentration, current density, pH, and treatment time. The results obtained have shown that optimum removal efficiency of 99.9% was realized at a current density of 20 mA/cm$^{2}$ and pH of 4.7. The adsorption process showed a pseudo-first-order kinetic model as the best fit to the EC data. Freundlich and Langmuir adsorption isotherms supported the adsorption of BTB on aluminum hydroxide being the in situ generated …


A Theoretical Investigation On The Activation Of Small Molecules By A Disilenide: A Dft Prediction, Cem Burak Yildiz, Akin Azi̇zoğlu Jan 2019

A Theoretical Investigation On The Activation Of Small Molecules By A Disilenide: A Dft Prediction, Cem Burak Yildiz, Akin Azi̇zoğlu

Turkish Journal of Chemistry

Herein, we proposed several mechanistic scenarios for activation of small molecules (NH$_{3}$, CO$_{2}$, CS$_{2}$, H$_{2}$, CH$_{4}$, N$_{2}$, and N$_{2}$O) by a disilicon analogue of a vinyl anion (1H) using density functional theory (DFT) calculations. The DFT results established that all the possible reactions to yield a variety of potential products have an exergonic nature except for the activation of N$_{2}$ with the obtained overall energy of $\Delta $G = 33.6 kcal mol$^{-1}$. Moreover, the highest exergonic character was $\Delta $G = $-$95.8 kcal mol$^{-1}$ for N$_{2}$O. Therefore, the findings reveal that 1H can be considered a suitable candidate for activation …


Sensitive Biological Detection Based On Langmuir--Blodgett Films Prepared From Diluted Silica Suspensions, Numan Gözübenli̇ Jan 2019

Sensitive Biological Detection Based On Langmuir--Blodgett Films Prepared From Diluted Silica Suspensions, Numan Gözübenli̇

Turkish Journal of Chemistry

Self-assembled three-dimensional (3-D) colloidal crystals have been extensively utilized in nanolithography for fabricating a wide spectrum of functional periodic nanostructures for important technological applications. Here a simple and versatile way is reported using silica colloids to prepare close-packed particle multilayers by the Langmuir--Blodgett technique to create highly ordered 3-D colloidal crystals with unusual nanoarrays on a large variety of substrates. Successive deposition of monolayers using amphiphilic molecules in this approach allows control of the layer thickness, particle size, and especially packing structure of them in each layer. It has been demonstrated that the Langmuir--Blodgett film's transparency and high antiglare optical …


Hydrogen Storage In Formic Acid As A Renewable Energy Source Using Heterogeneous Catalysis, Obaid Aldosari Jan 2019

Hydrogen Storage In Formic Acid As A Renewable Energy Source Using Heterogeneous Catalysis, Obaid Aldosari

Turkish Journal of Chemistry

One of the most vital chemicals, which is not only found naturally but can also be synthesized in the laboratory, is formic acid (FA). FA is a key byproduct of several second-generation biorefinery processes as well, and it is used in several pharmaceutical and industrial applications. Recently, another significant use of FA that is taking the lead is as a form of fuel. This could either involve reformation, as a possible form of chemical hydrogen storage, or be done without reformation in the form of FA fuel cells, in particular because FA fuel cells are much more effective than other …