Chemistry Commons^™

Study On Moo3/Sba-16 Catalyzed Transesterification To Synthesize Diphenyl Carbonate, Ying Li, Shunwu He

Turkish Journal of Chemistry

In this paper, the mesoporous molecular sieve SBA-16 with good dispersion was prepared by hydrothermal method. Under the condition of Si/Mo= 1.0, MoO₃/SBA-16 catalysts were prepared by iso-dipping method at 550 °C, 650 °C and 750 °C calcination temperature, which for the synthesis of diphenyl carbonate (DPC) from dimethyl carbonate (DMC) and phenyl acetate (PA) was used, and the uncalcined MoO₃/SBA-16 was used as a reference. XRD, TG-DTA, XPS, ICP-MS, FT-IR, BET, SEM and TEM characterization. The effects of calcination temperature and reaction conditions on the catalytic performance of MoO3/SBA-16 in transesterification of DMC and PA …

Adsorptive Removal Of Crystal Violet From Aqueous Solution By Ultrasonic-Assisted Synthesized Zirconium-2,6-Naphthalenedicarboxylate Metal-Organic Framework, Penmethsa Kiran Kumar, Sunkara Satya Veni

Turkish Journal of Chemistry

Zirconium-2,6-naphthalenedicarboxylate metal-organic framework (Zr-NDC MOF) was prepared using ultrasound-assisted synthesis and tested for the adsorptive removal of crystal violet (CV) dye from aqueous solution. The pristine Zr-NDC was characterized using powder X-ray diffraction, scanning electron microscopy, thermogravimetric analysis, and energy-dispersive X-ray spectroscopy, Fourier-transform infrared, elemental analysis, and dynamic light scattering techniques. The maximum percentage removal of CV dye was found to be 99.45% with an initial dye concentration of 10 mg L^-1. The kinetics and adsorption isotherm models were used to investigate the removal of CV dye from aqueous solution using Zr-NDC. Langmuir adsorption isotherm model (R^{2 …}

Synthesis, Characterization, And Antimicrobial Evaluation Of Polyvinylalcohol-Osthol Composite Films, Ishrat Gowsia, Feroz Mir, Javid Banday

Turkish Journal of Chemistry

Although poly-vinyl alcohol (PVA) has certain mechanical drawbacks such as a weak barrier, it has widely been used in food packaging over the last many years. To increase the suitability of PVA (C₂H₄O)n and render it ideal for food packaging, a diversity of studies have already been carried out. In the below-mentioned script, we, for the first time, report the use of natural product osthol in making a new composite with PVA for enhancing thermal, physicochemical, and antimicrobial properties. The significant aim of the report is the insertion of osthol (C₁₅H₁₆O_{3 …}

Chromatographic Profile Of Major Whey Proteins In Some Dairy Beverages Based On Milk Serum, Doina Prodan, Miuta Filip, Mihaela Vlassa, Marioara Moldovan, Rahela Carpa

Turkish Journal of Chemistry

The aim of this study was the determination of chromatographic profiles of major whey proteins (WP): α-lactalbumin (α-La), β-lactoglobulin A and B, (β-Lg A and B), bovine serum albumin (BSA) in dairy beverages based on Zonar milk serum. The studied WP were separated by high-performance liquid chromatography (HPLC) on Aeris XB-C18 column using gradient elution with 0.1% trifluoroacetic acid (TFA) in water and 0.1% TFA in 80% acetonitrile, at 214 nm detection. The HPLC method was validated for system suitability, selectivity/specificity, linearity (R² ≥ 0.996), precision (RSD% ≤ 2.01), trueness (recovery 96.29%-102.08%), sensitivity (limits of quantification (LOQ) 1.35-10.08 μg/mL), …

Miscibility And Thermal Behavior Of Poly(Methyl Methacrylate) And Polystyrene Blend Using Benzene As A Common Solvent, Arshiya Iqbal, Jamil Muhammad, Farzana Ahmad, Mohsan Nawaz, Musa Kaleem Baloch, Luqman Mohammad

Turkish Journal of Chemistry

Polymer blending is one of the advanced technologies to attain polymeric material with tailored properties. In this work, the miscibility of Poly(methyl methacrylate) (PMMA) and Polystyrene (PS) blend in benzene was investigated by employing various techniques such as FTIR spectroscopy, viscosity measurement technique, light scattering techniques, DSC and TGA techniques over an extended range of concentrations, compositions, and temperatures. The results revealed that there exist hydrogen bonding and hydrodynamic interactions which led these polymers to get miscible to a large extent. The compatibility increased with the increasing PS contents or increase in temperature of the system. In addition, the thermal …

Encapsulation Of Halocadmate Anion Via Hydrogen Bonding: Synthesis And Characterization Of Bis(Diethylenetriamine)Cobalt(Iii) Complex Containing Hexabromocadmate Anion, Vinit Prakash, Ritu Bala, Amrinder Kaur, Daron E. Janzen

Turkish Journal of Chemistry

In this work, the encapsulation of [CdBr₆]^4- by six cations, [Co(dien)₂]³⁺ has been described with the help of single crystal X-ray structural study in the complex, mer-[Co(dien)₂]₂[CdBr₆]Br₂. The complex anion, [CdBr₆]^4- has been obtained through solution method while attempting to synthesize complex dianion, [CdBr₄]^2-. This newly synthesized complex has been initially characterized by elemental analyses and spectroscopic studies (IR, NMR and UV-Visible). IR and NMR studies have been used for the isomeric identification of [Co(dien)₂]^{3+ …}

Removal Of Polycyclic Aromatic Hydrocarbons (Pahs) From Water Through Degradable Polycaprolactone Electrospun Membrane, Fuat Topuz

Turkish Journal of Chemistry

Polycyclic aromatic hydrocarbons (PAHs) are common and persistent environmental pollutants produced during the incomplete combustion of fuels. They are known for their carcinogenic and mutagenic properties. Thus, their removal from water bodies is highly crucial and has become a critical issue globally. As a solution, here an electrospun polycaprolactone (PCL) membrane with a mean fiber diameter of 2.74 ± 1.3 μm was produced by electrospinning. Water contact angle (WCA) analysis confirmed the hydrophobic nature of the PCL membrane with a WCA of 124°, which remained stable over time. Differential scanning calorimetry analysis (DSC) revealed the semicrystalline nature of the membrane …

The Relation Between Surface Acidity And Moo3:Al2o3 Ratio On The Ternary Mixed Oxide Catalysts For The Conversion Of Propan-2-Ol, Hani Zeidan, Ebru Erünal, Mustafa Esen Marti

Turkish Journal of Chemistry

In this study, ternary mixed oxide catalysts containing Al₂O₃-MoO₃-MgO and Al₂O₃-MoO₃-WO₃ were prepared with a changing ratio of MoO₃:Al₂O₃ between 0.05 and 20.00. All catalysts showed 100% selectivity towards propene during the conversion of propan-2-ol at temperatures between 220 and 400 °C. The catalysts prepared from WO₃ possessed very strong acid sites, which cause higher catalytic activity than catalysts prepared from MgO. Besides, the ratio of MoO₃:Al₂O₃ was found to be directly proportional to the conversion …

Investigation Of Glycerol Electrooxidation Activity Of Carbon Supported Pdcu Bimetallic Electrocatalyst, Kübranur Ağtoprak, Merve Doğan Özcan, Ayşe Ni̇lgün Akin, Rami̇z Gülteki̇n Akay

Turkish Journal of Chemistry

In this study, Pd/C, Cu/C, and a series of PdCu/C bimetallic electrocatalysts were prepared by microwave-assisted modified polyol method to determine glycerol electrooxidation reaction (GOR) activities. The effect of microwave duration on catalyst structure and GOR activity was investigated on PdCu/C bimetallic catalysts. Also, a commercial Pd/C (com-Pd/C) was used to compare catalytic activities with prepared samples. Electrocatalysts were characterized by using X-ray Diffraction (XRD), Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES), and Transmission Electron Microscopy (TEM) analyses. In addition, the activity and stability of electrocatalysts for GOR were examined by using cyclic voltammetry (CV) and chronoamperometry (CA). In XRD …

Determination Of Si/Graphite Anode Composition For New Generation Li-Ion Batteries: A Case Study, İlknur Kalafat, Nesli̇han Yuca

Turkish Journal of Chemistry

Silicon with the properties of high capacity capability, moderate working potential, environmental sensitivity, and existence are the highly promising anode materials for lithium-ion batteries. Silicon anodes have disadvantageous properties and advantages like 300% volume change during lithium insertion and extraction process that can result in capacity fading and a shorter lifetime of the battery. In the literature, different optimizations of Silicon with different nanomaterials or composite materials, in different ratios, and with different binders and different procedures have been studied. The physical mixing of silicon with carbon provides a good performance by combining the high lithium storage capacity of the …

Students’ Perceptions Of Specific Laboratory Curricula On The Learning Experience In Chemistry Courses, Arwa Ali Alshehri

Electronic Theses and Dissertations

Laboratory courses play a key role in developing critical thinking and problem-solving skills and providing experience in certain aspects of a laboratory setting including reactions, materials, and equipment. Prior studies suggest that a laboratory course assists students toward cognitive gain on lecture content. In contrast, other studies conclude that laboratory is uncorrelated with cognitive gain on lecture content. Thus, a discord exists between researchers regarding the role that laboratory experiences play in furthering the understanding of chemistry concepts taught in lectures. The purpose of this research is to examine the impact of two different laboratory curricula on students’ performance in …

Development Of A Chromatographic Method To Authenticate Aspirin Brands, Megan Guetzloff

Electronic Theses and Dissertations

Counterfeit pharmaceuticals pose a threat to society that can include inaccurate amounts of the active pharmaceutical ingredient (API), no API, or containing off-target compounds. For example, there are many recent examples of counterfeit pharmaceuticals containing potentially lethal doses (> 2 mg) of fentanyl (i.e., a synthetic opioid). Current measures to combat illicit pharmaceuticals (e.g., unique packaging and product serialization) have merit, however with evolved technologies, counterfeiters can relatively easily simulate these measures and continue to distribute illicit pharmaceuticals. The only accurate way to definitively determine that a suspected counterfeit is, in fact, counterfeit is advanced chemical analysis. However, current methods …

Review Of The Effects Of Asphalt Fume Emission (Vocs And Pahs) In Vitro, In Vivo And Human Studies, Omran Taqi, Nastassja Lewinski, Elham Fini, Eran Rozewski, Judith Klein-Seetharaman

Undergraduate Research Posters

Review of the effects of Asphalt fume emission (VOCs and PAHs) in vitro, in vivo and human studies

Omran Taqi, Nastassja Lewinski¹

1) Department of Chemical and Life Science Engineering, Virginia Commonwealth University, Richmond, VA

Background

Asphalt is abundantly available around human operations including road paving and roofing sites. However, their emissions and fumes (specifically volatile organic compounds (VOCs) and polycyclic aromatic hydrocarbons (PAHs)) have been found to have adverse effects on health. Asphalt fumes are a class 2A carcinogen and exposure can increase the risk of lung cancer, asthma, headache, fatigue, and other cardiovascular diseases.

Methods

We used …

Exploring The Photophysics Of Brown Carbon Chromophores Using Laser-Based Spectroscopy And Computational Methods, Megan Elizabeth Alfieri

Dissertations, Theses, and Masters Projects

Atmospheric aerosols are made up of suspended liquids and solids in the atmosphere. These aerosols play a very important role in the solar energy exchange in Earth’s atmosphere as well have dramatic impact on human health. Different aerosols have different effects on the atmosphere depending on the physical properties of the aerosols.

The purpose of this research project is to understand how the structure of molecular chromophores impacts the solar absorption properties of aerosols. We propose a series of laboratory studies to investigate the outcomes from solar absorption of brown carbon chromophores: 1-phenylpyrrole, 2-phenyl-1-H-pyrrole, 2-phenylimadazole, as well as water complexes. …

Induction Of Lutein Production In Scenedesmus Obliquusunder Different Culture Conditions Prior To Its Semipreparative Isolation, Ayşegül Erdoğan, Ayça Büşra Karataş, Zeli̇ha Demi̇rel, Meltem Dalay

Turkish Journal of Chemistry

Microalgae with their improved growth rates and accumulation of high-value-added products make their commercial production attractive. Among them, lutein, which is a carotenoid, plays a very important role due to its various applications in the food and pharmaceutical industry. Induction of its biosynthesis can be triggered by various stress conditions like light. In this study, three different light intensities (50,150 and 300 μmol photons/m2s) and aeration rates (1, 3, and 5 L/min) were utilized to induce the lutein biosynthesis and biomass productivity in Scenedesmus obliquus. Lutein was isolated by preparative chromatography using a semiprep C30 column (10 × 250 mm, …

Ultrafiltration-Based Sample Preparation And Hplc-Uv Determination Of Diclofenac In Human Plasma Samples, Merve Nenni̇, Ayşegül Doğan, Mustafa Çelebi̇er, Murat Soyseven, Mustafa Si̇nan Kaynak, Hassan Y. Aboul-Enein, Göksel Arli̇

Turkish Journal of Chemistry

The sample preparation step is the initial step in pharmaceutical analysis. While ultrafiltration is a well-known technique used in the food and pharmaceutical industries, it has rarely been used to measure the plasma concentration of active pharmaceutical ingredients. This study aimed to analyze diclofenac sodium (DS) in human plasma samples using ultrafiltration-based sample preparation before high-performance liquid chromatography (HPLC) analysis. The advantages and limitations of ultrafiltration-based sample preparation in bioanalysis were evaluated by comparing the results with conventional methods. The precipitating agent was used before ultrafiltration. The analysis was carried on an HPLC-UV system with a C18 column (250 ×4.6 …

Synthesis And In Vitro Α-Glucosidase And Cholinesterases Inhibitory Actions Of Watersolublemetallophthalocyanines Bearing ({6-[3-(Diethylamino)Phenoxy]Hexyl}Oxy Groups, Turgut Keleş, Zekeri̇ya Biyiklioğlu, Di̇dem Akkaya, Arzu Özel, Burak Barut

Turkish Journal of Chemistry

In this paper, we have prepared peripherally tetra-({6-[3-(diethylamino)phenoxy]hexyl}oxy substituted cobalt(II), copper(II), manganese(III) phthalocyanines (3, 4, 5) and their water-soluble derivatives (3a, 4a, 5a). Then, in vitro α-glucosidase and cholinesterases inhibitory actions of the water-soluble 3a, 4a, 5a were examined using spectrophotometric methods. 4a had the highest inhibitory effects among the tested compounds against α-glucosidase due to IC50 values. 4a and 5a had 40 fold higher inhibitory effects than the positive control. For cholinesterases, the compounds showed significant inhibitory actions that of galantamine which was used as a positive control. According to the SI value, 3a inhibited acetylcholinesterase enzyme selectively. In …

Ferrihydrite/Ultrasound Activated Peroxymonosulfate For Humic Acid Removal, Hang Yang, Yi Zhang, Shibin Xia

Turkish Journal of Chemistry

In this study, ferrihydrite/ultrasound (US) system was used to activate peroxymonosulfate (PMS) to treat humic acid (HA) in artificial aqueous. The physical and chemical properties of ferrihydrite were characterized using SEM, zeta potential, BET, XRD, FTIR, and XPS analysis. A series of experiments were conducted to evaluate the effect of various factor on HA removal, including dosage of ferrihydrite, PMS concentration and pH value. The combination uses of US and ferrihydrite had obvious synergistic effect for HA removal. Under ferrihydrite/US/PMS system, nonthermal effect of US played the main role for HA removal. According to the result of radical quenching experiment, …

Electroanalytical Investigation And Voltammetric Quantification Of Antiviral Drug Favipiravir In The Pharmaceutical Formulation And Urine Sample Using A Glassy Carbon Electrode In Anionic Surfactant Media, Zeynep Akca, Hande İzem Özok, Yavuz Yardim, Zühre Şentürk

Turkish Journal of Chemistry

This work describes the electrochemical investigation of a promising antiviral agent, favipiravir (FAV) utilizing a nonmodified glassy carbon (GC) electrode, along with a unique voltammetric approach that can determine FAV with a good degree of accuracy, speed, and cost-effectiveness. Using cyclic voltammetry, the compound demonstrated a single well-defined and an irreversible oxidation peak at approximately +1.12 V (vs. Ag/AgCl) in Britton-Robinson (BR) buffer at pH 10.0. The synergistic effect of anionic surfactant, sodium dodecyl sulfate (SDS) on the adsorption ability of GC electrode remarkably increased the sensitivity of the stripping voltammetric measurements of FAV. Employing square-wave adsorptive stripping voltammetry at …

Microstructure And Ionic Conductivity Investigation Of Samarium Doped Ceria(Sm0.2ce0.8o1.9) Electrolytes Prepared By The Templating Methods, Di̇lara Güçtaş, Vedat Sariboğa, Mehmet Ali̇ Faruk Öksüzömer

Turkish Journal of Chemistry

Sm0.2Ce0.8O1.9 (SDC20) electrolytes were synthesized with cellulose templating (CT) and PVA templating (PVAT) methods. Powder characteristics were examined using TG/DTA, XRD, and SEM. Pellets are sintered at various temperatures for different durations. Mean grain sizes were calculated from SEM micrographs using the linear intercept method. Grain growth behavior of the electrolytes was investigated and the dominant diffusion mechanism was examined. The grain growth activation energies were obtained for the first time for the mentioned electrolytes prepared by the mentioned methods. The ionic conductivities were calculated by electrochemical impedance spectroscopy. The highest ionic conductivity value was found to be 0.050 S …