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Full-Text Articles in Chemistry

A Conceptual Understanding Of Concepts In Organic Chemistry, Timerra Chisham May 2024

A Conceptual Understanding Of Concepts In Organic Chemistry, Timerra Chisham

Theses/Capstones/Creative Projects

As students continue to make the transfer into organic chemistry from general chemistry, they will have to adjust to the new type of thinking required so that they will not fall behind in understanding material and will have success in the course. For this research project, I explored which concepts taught in organic chemistry are the most difficult for students to grasp. I had two main goals for this project. The first one is the central idea that I focused on, which was to see which concepts that have been taught in Organic Chemistry 1 the students are most confident …


Biotinylated Protein Capture And Tween-20 Assisted Exosome Isolations Via Capillary Chanelled Polymer Fiber, Md Khalid Bin Islam May 2024

Biotinylated Protein Capture And Tween-20 Assisted Exosome Isolations Via Capillary Chanelled Polymer Fiber, Md Khalid Bin Islam

All Theses

In the past two decades, Marcus and colleagues have led the advancement of capillary-channeled polymer (C-CP) fiber stationary phases for biomacromolecule separations, including proteins and nanovesicles. These stationary phases offer notable advantages, including low cost ($5/column), straightforward column fabrication, and the capacity for on-column surface modification, enabling high chemical selectivity. This study examines a C-CP fiber modification strategy for capturing target proteins and develops a Tween-20-assisted C-CP-based hydrophobic interaction chromatography (HIC) method for the isolation and quantification of exosomes from human urine.

The quest for higher-throughput and cost-effective protein isolation techniques remains a key focus in a variety of end …


Effects Of Ecologically Relevant Concentrations Of Nitrate On Behavior In Betta Splendens, Sarah Janson May 2024

Effects Of Ecologically Relevant Concentrations Of Nitrate On Behavior In Betta Splendens, Sarah Janson

Honors College

Nitrate is a ubiquitous pollutant that is becoming more prevalent in both fresh and saltwater environments. Short term effects are often studied, but an organism’s response to stress can change due to whatever the stressor is. In order to research this, a study was run using environmentally relevant nitrate treatments (0 mg/L, 10 mg/L NO3-N, and 100 mg/L NO3-N) to see the effect of nitrate on scototaxis behaviors, a measure of anxiety. This study used Betta splendens because they are easy to rear and have very well documented behaviors. In addition to the scototaxis, the effect of temperature on mortality …


Using Cdom Optical Properties To Estimate Its Source, Distribution, And Doc Conentration In Maine Estuaries, Camille Michaud May 2024

Using Cdom Optical Properties To Estimate Its Source, Distribution, And Doc Conentration In Maine Estuaries, Camille Michaud

Honors College

Colored dissolved organic matter (CDOM) contributes largely to ocean color, and therefore, influences processes and applications that interact with light in the ocean such as remote sensing and biogeochemistry. It is a component part of dissolved organic carbon (DOC) and there is a strong relationship in coastal waters between CDOM absorption and DOC concentration. CDOM optical properties also vary with salinity and source. These important aspects of CDOM absorption led us to collect CDOM samples across the salinity gradients of 3 estuaries in Maine: the Penobscot, Damariscotta, and Sheepscot. We sampled stations along the salinity gradient in each estuary from …


Ecological Effects And Ethics Of A Species Range Shift To High Elevation Ponds, Ava Ardito May 2024

Ecological Effects And Ethics Of A Species Range Shift To High Elevation Ponds, Ava Ardito

Honors College

As temperatures warm, the climate crisis is having a significant influence on species across the world and altering their distributions. Colorado's high elevation ponds have recently observed a species range shift, traveling to higher altitudes than they have previously inhabited. The Mexican Cut Nature Preserve near the Rocky Mountain Biological Laboratory (RMBL) in Gothic, CO, is home to a prominent caddisfly Limnephilus externus, but recently a new range-shifting species, Nemotaulius hostilis, has appeared. Caddisflies play an essential role in nutrient cycling and putting energy back into the food web. The range-shifting species is known to excrete high rates of phosphorus …


Evaluating The Accuracy Of Different Remote Sensing Methods Used To Derive Absorption From Chromophoric Dissolved Organic Matter In Maine Estuaries, Andrea Rudai May 2024

Evaluating The Accuracy Of Different Remote Sensing Methods Used To Derive Absorption From Chromophoric Dissolved Organic Matter In Maine Estuaries, Andrea Rudai

Honors College

Current knowledge of dissolved organic carbon (DOC) in Maine estuaries is based on limited field research. By using chromophoric dissolved organic matter (CDOM) as a proxy, it is possible to use satellite images to estimate the concentration of DOC in an entire body of water. This study aims to evaluate different methods that calculate absorption by CDOM from ocean color remote sensing using images taken by Landsat 9 of the Sheepscot, Penobscot, and Damariscotta rivers. The study revealed that although there were some similarities in along-estuary trends between the remotely- sensed absorption and absorption measured in situ, the algorithms that …


The Synthesis And Characterization Of 9,10-Bis-(Iodoethynyl)Anthracene For 2d Molecular Crystals From Halogen-Bonding, Nehemiah Antoine May 2024

The Synthesis And Characterization Of 9,10-Bis-(Iodoethynyl)Anthracene For 2d Molecular Crystals From Halogen-Bonding, Nehemiah Antoine

Honors Theses

Two-dimensional crystals have unique properties, giving them the potential to develop practical items such as electronics, biomedicine, and sensors. Our goal is to use chemical principles to synthesize molecules that spontaneously form 2D crystals with designed patterns and properties. For this, we will exploit directional, non-covalent interactions to determine what pattern will form in 2D. In this project halogen-bonding will be utilized: halogen-bonding is the interaction between the electrophilic region of a halogen and a nucleophilic region of a Lewis base. We are functionalizing anthracenes with iodine and nitrogen to form halogen bonds that enable the molecules to pack more …


Investigation Of Magnetic, Spectroscopic, And Structural Properties Of Molecular Metal Compounds, Alexandria Bone May 2024

Investigation Of Magnetic, Spectroscopic, And Structural Properties Of Molecular Metal Compounds, Alexandria Bone

Doctoral Dissertations

Compounds exhibiting single-molecule magnetism (SMM) are of current interest for potential use in molecular data storage and quantum computing applications. However, rapid magnetic relaxation at desired operating temperatures currently limits the use of these materials, and a more thorough understanding of the magnetic and vibrational transitions that affect magnetic memory is required to inform SMM design. The primary focus of this dissertation is the study of magnetic and vibrational modes in molecular magnetic compounds via advanced spectroscopic techniques such as inelastic neutron scattering (INS), far-IR magneto-spectroscopy (FIRMS), and high-field, high-frequency electron paramagnetic resonance (HFEPR) to directly observe transitions among zero-field …


Investigating Small Molecule Behavior In Living Bacterial Membranes With Second Harmonic Scattering, Marea J. Blake May 2024

Investigating Small Molecule Behavior In Living Bacterial Membranes With Second Harmonic Scattering, Marea J. Blake

Doctoral Dissertations

A molecule's entry into a cell is impeded primarily at the surface of Gram-positive bacteria. This interface serves as the boundary separating cellular contents from the external environment and is composed of a thick layer of peptidoglycan and a lipid bilayer equipped with protein and lipid species with various roles including that of small-molecule transport. As such, understanding these molecule-membrane interactions is imperative to examine in order to design novel drugs or adjuvants to combat the global antibiotic resistance predicament. Knowledge regarding passive diffusion and overall organization of small molecules in the lipid bilayer of living Gram-positive cells is limited …


Development Of Chiral Lewis Base Catalysts For Chlorosilane-Mediated Asymmetric C-C Bond Formations, Changgong Xu May 2024

Development Of Chiral Lewis Base Catalysts For Chlorosilane-Mediated Asymmetric C-C Bond Formations, Changgong Xu

Theses and Dissertations

The chiral hydrazine is a crucial structural motif that serves as pivotal structural elements in numerous natural products and biologically significant molecules. We are particularly interested in the catalytic asymmetric reduction of hydrazones, as well as the catalytic asymmetric propargylation and allenylation of hydrazones, because they provide direct pathways to these enantio-enriched chiral building blocks. In this work, we will explore the potential of two different categories of chiral Lewis base catalysts in the said transformations.

Developed by another student in our group, axial-chiral 3,3’-triazolyl biisoquinoline N,N’-dioxides derived catalysts are tested and demonstrated its capability in activating various hydrazone …


Argonaute 2 Binding Affinity To Determine Repression Of Mirna-Mrna Pairs, Christina M. S. Karadiakos May 2024

Argonaute 2 Binding Affinity To Determine Repression Of Mirna-Mrna Pairs, Christina M. S. Karadiakos

ALL - Honors Theses

MicroRNAs (miRNA) are a class of small non-coding RNAs that play a key role in gene silencing. miRNAs form an RNA-induced silencing complex (RISC) with the argonaute 2 (AGO2) protein in order to control gene expression through silencing messenger RNAs (mRNA). The ability for a miRNA-mRNA complex to fit into AGO2 and form the RISC is based on the location and characteristics of a central bulge, but the mechanism and interactions that lead to a functional RISC remain unknown. Using available experimental data, we modeled complexes composed of a miRNA (miR-34a) and different mRNA sequences inside of AGO2. The resulting …


A Comparative Analysis Of Field Electron Emission From Carbon Black Embedded Within Insulated Copper Hollowed Wires And Glass Tubes, Hatem A. Al-Braikat, Ahmad M D Jaber, Adel M. Abuamr, Mazen A. Madanat, Aseel A. Al-Jbarart, M-Ali H. Al-Akhras, Marwan S. Mousa Apr 2024

A Comparative Analysis Of Field Electron Emission From Carbon Black Embedded Within Insulated Copper Hollowed Wires And Glass Tubes, Hatem A. Al-Braikat, Ahmad M D Jaber, Adel M. Abuamr, Mazen A. Madanat, Aseel A. Al-Jbarart, M-Ali H. Al-Akhras, Marwan S. Mousa

Karbala International Journal of Modern Science

In this study, two different methods are used to investigate carbon black as a cold field electron emitter. The first method is to incorporate carbon black into a specially designed insulated copper hollowed wire. The wire has a cup-shaped structure created by electrochemical etching. The second method involves the incorporation of carbon black into narrow glass tubes. A Comparative analyses is carried out to evaluate the effectiveness of each method. To evaluate the performance of the samples, the current-voltage characteristics will be examined using field electron microscopes. This analysis will provide an understanding of the emission of the carbon black …


Surface Treatments' Effects On The Capacitor's Dielectric Performance Under Electro-Thermal Stresses, Haider. M. Umran, Feipeng Wang Apr 2024

Surface Treatments' Effects On The Capacitor's Dielectric Performance Under Electro-Thermal Stresses, Haider. M. Umran, Feipeng Wang

Karbala International Journal of Modern Science

Biaxial-oriented polypropylene (BOPP) films are characterized by unfavorable aging behavior because of their poor susceptibility to high temperatures, humidity, and high electric fields. This makes them unqualified to withstand harsh operating conditions, such as in capacitor applications. This study investigates the impact of annealing BOPP samples at 100 °C for five hours after fluorination at different times (15, 30, and 60 minutes) on their electrical and mechanical performance under electro-thermal stresses. Scanning electron microscope (SEM) images confirm that there is an increase in surface roughness and the formation of a dense layer of fluorine-containing groups monotonically with fluorination time. So, …


Electrocatalytic Cyclopropanation Of Active Methylene Compounds, Liang-Hua Jie, Hai-Chao Xu Apr 2024

Electrocatalytic Cyclopropanation Of Active Methylene Compounds, Liang-Hua Jie, Hai-Chao Xu

Journal of Electrochemistry

The development of novel strategies to access cyclopropanes has become increasingly important due to the vital role of these three-membered ring structures in synthetic intermediates, natural products, and pharmaceuticals. Herein, we present an electrocatalytic method for the synthesis of cyclopropanes through intermolecular dehydrogenative annulation of active methylene compounds and arylalkenes. This electrochemical process requires no chemical oxidants, allowing for a speedy access to various functionalized cyclopropanes from inexpensive and readily available materials.


Electrochemical Syntheses Of Aryl-Substituted Benzothiophenes And Phenanthrenes Using Benzenediazonium Salts As The Aryl Radical Precursors, Li-Yuan Lan, Yang-Ye Jiang, Raymond Daniel Little, Cheng-Chu Zeng Apr 2024

Electrochemical Syntheses Of Aryl-Substituted Benzothiophenes And Phenanthrenes Using Benzenediazonium Salts As The Aryl Radical Precursors, Li-Yuan Lan, Yang-Ye Jiang, Raymond Daniel Little, Cheng-Chu Zeng

Journal of Electrochemistry

Aryl-substituted benzothiophene and phenanthrene are important structural units in medicinal chemistry and materials science. Although extensive effort has been devoted to prepare these compounds and a variety of approaches have been developed to construct the 2-substituted benzothiophene core structure, environmental-friendly and efficient synthetic means are still desired. Based on our previous electrochemical Minisci-type arylation reaction with aryl diazonium salt as the aryl precursor, as well as the work from König’s group, herein, we described the use of paired electrolysis to achieve 2-aryl benzothiophenes and 9-aryl phenanthrenes employing benzenediazonium salts as the aryl radical precursors. Initially, 2-methylthiobenzendiazonium salt 1a and 4-methylbenzene …


Electrochemical Advanced Treatment Of Desulfurization Wastewater From Coal-Fired Power Plants, Ju-Cai Wei, Juan Yi, Xu Wu Apr 2024

Electrochemical Advanced Treatment Of Desulfurization Wastewater From Coal-Fired Power Plants, Ju-Cai Wei, Juan Yi, Xu Wu

Journal of Electrochemistry

Zero-emission of desulfurization wastewater is one of the main demands for coal-fired power plants. As typical high salinity wastewater, it is hard to purify the desulfurization wastewater from coal-fired power plants through traditional physicochemical treatment or biochemical treatment, e.g., COD and Cl. A high concentration of Cl ion in desulfurization wastewater restricts wastewater reuse and zero-emission. Electrochemical technology is an attractive method for high salinity wastewater zero-emission, which provides a versatile, efficient, cost-effective, easily automatable, and clean industrial process. For advanced treatment of effluent after triple box process treatment in power plants, this paper reports an electrochemical …


Synthesis And Characterization Of Silver(I) And Manganese(Ii) Complexes With Thione Imidazoles, Shannon Keyser, Audrey Lawrence, Jaime M. Murphy Ph.D. Apr 2024

Synthesis And Characterization Of Silver(I) And Manganese(Ii) Complexes With Thione Imidazoles, Shannon Keyser, Audrey Lawrence, Jaime M. Murphy Ph.D.

Honors Theses

Coordination polymers are chemical complexes with versatile applications such as catalysts, electrical conduc-tors, non-linear optics, magnetics, chemical sensing, and molecular storage. The polymers are comprised of a repeating series of metal-ligand complexes, which form various structures in varying ratios depending on the metal and ligand used. Certain metal-ligand combinations have shown particular promise as potentially being polymers or, if not polymers, possessing other useful features such as electromagnetic conductivity. Complexes were synthesized using silver(I) and manganese(II) with the ligands methimazole, 2-mercaptoimidazole, and thiocarbanilide with counterions of either chloride or nitrate. These com-plexes were characterized using elemental analysis, infrared spectroscopy, and …


The Purification And Thermal Stability Of The Peroxidase Enzyme In Cucurbita Moschata, Garen Hamner Apr 2024

The Purification And Thermal Stability Of The Peroxidase Enzyme In Cucurbita Moschata, Garen Hamner

Senior Honors Theses

Peroxidases are enzymes that catalyze the reduction of hydrogen peroxide to water while oxidizing organic substrates and are valuable in spheres like industrial and medical applications and histochemistry. Limitations still exist in the use of the well-studied horseradish peroxidase for certain activities due to limitations like poor thermal stability, thus the search for novel peroxidases that can overcome these limitations is an active area of research. Butternut squash peroxidase (Cucurbita moschata) (BSP) shows promise due to significant activity being found in the skin and apparent enhanced thermal stability, but an efficient purification scheme for it is lacking, as well as …


X-Ray Fluorescence Analysis Of Historic Art Paint Pigments, Sofia A. Stirpe, Juergen Thieme Apr 2024

X-Ray Fluorescence Analysis Of Historic Art Paint Pigments, Sofia A. Stirpe, Juergen Thieme

Binghamton University Undergraduate Journal

Utilizing synchrotron radiation, X-ray fluorescence (XRF) microscopy enables researchers to deduce the elemental composition of paint pigments with a higher sensitivity and resolution than that of lab-based XRF instruments. With this information, art historians can date paintings by examining the elemental makeup of paint pigments and the time periods in which they were used. One painting, Christ and the Woman Taken in Adultery, has been duplicated by Pieter Brueghel the Younger and other artists, leading to confusion over which artworks are Brueghel masterpieces or copies by other artists. Art historian Maurizio Seracini, retaining a painting that could be assigned …


Performance Test Of Zn-Astaxanthin Complex-Sensitized Solar Cell: Effect Of Light Intensity On Open-Circuit Voltage And Short-Circuit Current Values, Septiani Septiani, Winda Rahmalia, Thamrin Usman Apr 2024

Performance Test Of Zn-Astaxanthin Complex-Sensitized Solar Cell: Effect Of Light Intensity On Open-Circuit Voltage And Short-Circuit Current Values, Septiani Septiani, Winda Rahmalia, Thamrin Usman

Turkish Journal of Chemistry

The sensitizer is one of the most essential dye-sensitized solar cell (DSSC) components. In the present research, a Zn-astaxanthin complex was investigated as a sensitizer, compared to pure astaxanthin. The complex with a 1:1 mole ratio between astaxanthin and Zn2+ was synthesized in a reflux reactor at 37–60 °C. The product was analyzed using Proton Nuclear Resonance (1H-NMR), which indicates the presence of chelate formation between Zn2+ with two atoms of oxygen on the terminal cyclohexane ring of astaxanthin. The interaction of sensitizers (astaxanthin and Zn-astaxanthin) on the photoelectrode surface in this study was analyzed using a Fourier Transform Infra-Red …


Sensitive And Accurate Determination Of Oil-Soluble And Water-Soluble Organosulfur Compounds In Garlic Matrix Using Reversed Phase-High Performance Liquid Chromatography, Ümmügülsüm Polat Korkunç, Buse Tuğba Zaman, Sezgi̇n Bakirdere, Emine Karakuş Apr 2024

Sensitive And Accurate Determination Of Oil-Soluble And Water-Soluble Organosulfur Compounds In Garlic Matrix Using Reversed Phase-High Performance Liquid Chromatography, Ümmügülsüm Polat Korkunç, Buse Tuğba Zaman, Sezgi̇n Bakirdere, Emine Karakuş

Turkish Journal of Chemistry

Garlic is in the family Liliaceae and has many different constituents such as organic sulfur compounds, amino acids, carbohydrates, minerals, and vitamins. In this work, a simple, sensitive, and accurate analytical method was developed for the determination of selected organosulfur compounds (OSCs) in garlic bulbs using reversed phase-high performance liquid chromatography (RP-HPLC). Oil-soluble and water-soluble OSCs were extracted from the garlic samples via acetonitrile and deionized water, respectively. The OSCs were separated on a Phenomenex C18 (250 mm, 4 mm, 5mm) column and the monitoring was performed with a UV detector at 220 nm. An isocratic mobile phase comprising of …


Hummers’ Method-Assisted Liquid-Phase Exfoliation Enables The Fabrication Of Few-Layer Borophene From Bulk Boron, Mehmet Semih Bingöl, Mehmet Yilmaz, Ahmet Emre Kasapoğlu Apr 2024

Hummers’ Method-Assisted Liquid-Phase Exfoliation Enables The Fabrication Of Few-Layer Borophene From Bulk Boron, Mehmet Semih Bingöl, Mehmet Yilmaz, Ahmet Emre Kasapoğlu

Turkish Journal of Chemistry

The fabrication of few-layer borophene (BP) from bulk boron (b-B) is of great importance and still a scientific challenge due to the complex structure and crystallinity of b-B. Herein, we propose a novel technique to prepare a few-layer BP on a large scale with a large lateral size in a well-controlled manner. For this, we employed the Hummers’ method-assisted liquid-phase exfoliation. In the first step, the chemical exfoliation of the b-B as a precursor was performed by the modified Hummers’ method. After chemical exfoliation, mechanical delamination was employed by using an immersion sonicator. Finally, BP sheets were collected with dimensions …


Computational Drug Repurposing Effort For Identifying Novel Hits For The Treatment Of Diseases Such As Endometriosis, Uterine Fibroids, And Prostate Cancer, Ahmet Buğra Ortaakarsu, Hi̇lal Medetali̇beyoğlu Apr 2024

Computational Drug Repurposing Effort For Identifying Novel Hits For The Treatment Of Diseases Such As Endometriosis, Uterine Fibroids, And Prostate Cancer, Ahmet Buğra Ortaakarsu, Hi̇lal Medetali̇beyoğlu

Turkish Journal of Chemistry

This research aimed to identify potential drug compounds from the ZINC15 molecule database that could effectively treat GnRH1R-related diseases. The study utilized molecular docking and molecular dynamics methods to achieve this goal, which is crucial in drug repurposing research. The virtual screening process involved analyzing known drug compounds using molecular docking. Additionally, molecular dynamics simulations and MM-GBSA were employed to evaluate the stability of the complexes and determine the interactions between the compounds and protein structure. As a result, this study provides significant insights for treating diseases such as endometriosis, uterine fibroids, and prostate cancer related to GnRH1R. The study …


Development Of A New Nanosensor For The Determination Of Food Coloring Sunset Yellow In Powder Drinks Using L-Cysteine Coated Copper Nanoclusters, Mehmetcan Bi̇lkay, Büşra Karataş, Hayri̇ye Eda Şatana Kara Apr 2024

Development Of A New Nanosensor For The Determination Of Food Coloring Sunset Yellow In Powder Drinks Using L-Cysteine Coated Copper Nanoclusters, Mehmetcan Bi̇lkay, Büşra Karataş, Hayri̇ye Eda Şatana Kara

Turkish Journal of Chemistry

Sunset Yellow (SY), which is an artificial azo dye, is preferable for its high stability and low cost. The determination of SY in foods is extremely important for human health because excessive consumption of SY has harmful effects, such as hyperactivity disorder and cancer. In this method, L-cysteine ​​coated copper nanoclusters (CuNCs) were used as a fluorescence probe. L-cysteine ​​has been used as both a reducing and stabilizing agent. One-step green hydrothermal synthesis of CuNCs was made. L-cysteine-coated CuNCs have been characterized using several of methods. CuNCs quenching mechanism is static and inner filter effect (IFE). The linear range is …


Preparation Of Cholesterol-Imprinted Polymer For Selective Adsorption Of Cholesterol From Gastrointestinal Mimicking Solution, Veyi̇s Karakoç, Erol Erçağ Apr 2024

Preparation Of Cholesterol-Imprinted Polymer For Selective Adsorption Of Cholesterol From Gastrointestinal Mimicking Solution, Veyi̇s Karakoç, Erol Erçağ

Turkish Journal of Chemistry

The purpose of this study is to synthesize a highly selective adsorbent to remove cholesterol, one of the most important causes of cardiovascular diseases, from the intestinal mimic solution (IMS). For this purpose, cholesterol imprinted polymers were synthesized by suspension polymerization method using the molecular imprinting technique. In the first step, the functional monomer MATyr with hydrophobic character was synthesized. Then, the cholesterol-MATyr monomer precomplex was formed and the polymerization process was carried out by adding cross-linkers with the comonomer HEMA. The synthesized polymer poly(2-hydroxyethyl methacrylate-N-methacryloyl-(L)-tyrosine methylester) poly(HEMA–MATyr) was characterized by FTIR and SEM. The cholesterol adsorbing behavior of the …


Supramolecular Solvent-Based-Vortex-Assisted-Dispersive Liquid Liquid Microextraction Of Sudan Black B In Food Samples Prior To Spectrophotometric Detection, Fi̇gen Erek, Mustafa Tüzen Apr 2024

Supramolecular Solvent-Based-Vortex-Assisted-Dispersive Liquid Liquid Microextraction Of Sudan Black B In Food Samples Prior To Spectrophotometric Detection, Fi̇gen Erek, Mustafa Tüzen

Turkish Journal of Chemistry

A new, simple and rapid spectrophotometric method was developed for determination of Sudan Black B in food products by supramolecular solvent-based-vortex-assisted-dispersive liquid liquid microextraction (SUPRAS-VA-DLLME). Extraction solvent type, volume of solvent, pH, volume of THF, centrifugation time, vortex time, and sample volume were investigated as optimization parameters of the developed method. Under the optimum conditions, limit of detection and limit of quantification, preconcentration factor and enhancement factor of the developed method were calculated to be 9.01 µg L–1, 29.73 µg L–1, 20, and 55, respectively. The developed microextraction method was successfully applied to food samples for the determination of Sudan …


Graphene Aerogels: Part 2 - Derived From Commercial Graphene And Chemically Reduced Graphene Oxide Via Supercritical Carbon Dioxide Drying, Meryem Samanci, Ayşe Bayrakçeken Apr 2024

Graphene Aerogels: Part 2 - Derived From Commercial Graphene And Chemically Reduced Graphene Oxide Via Supercritical Carbon Dioxide Drying, Meryem Samanci, Ayşe Bayrakçeken

Turkish Journal of Chemistry

Graphene aerogels (GAs), the most important class of carbonaceous aerogels, have attracted attention of many researchers due to their superior physical and chemical properties. In this study, commercial graphene (GR) and chemically reduced graphene oxide (RGO) were used as graphene-based precursor materials, unlike graphene oxide (GO), which is widely used in the literature in GA synthesis. GAs were synthesized using the sol-gel technique and dried with supercritical carbon dioxide (SCCO2). In addition, graphene-based materials were used in different ratios and their distribution in the aerogel matrix and its effect on surface properties were investigated. In addition, the synthesized GAs were …


Graphene Aerogels: Part 1 - Derived From Graphene Oxide And Thermally Reduced Graphene Oxide Via Supercritical Carbon Dioxide Drying, Meryem Samanci, Ayşe Bayrakçeken Apr 2024

Graphene Aerogels: Part 1 - Derived From Graphene Oxide And Thermally Reduced Graphene Oxide Via Supercritical Carbon Dioxide Drying, Meryem Samanci, Ayşe Bayrakçeken

Turkish Journal of Chemistry

Graphene aerogels have become promising materials in many areas of industry, especially in energy applications due to their superior physical and electrochemical properties. Generally, graphene oxide (GO)-derived aerogels (A) are synthesized by using the hydrothermal method. In this study, both GO and reduced graphene oxide (RGO)-derived aerogels were synthesized by using the sol-gel method coupled with the supercritical carbon dioxide (SCCO2) drying process. It aims to examine the changes in the structure of the final aerogel by changing the amount (0.25–0.5–1% wt.) and type of graphene-based precursor materials used in the synthesis. Physical characterizations of graphene aerogels were conducted using …


Investigation Of Benzoic Acid And Sorbic Acid Concentrations In Tomato Paste, Pepper Paste, Ketchup, Mayonnaise, And Barbeque Sauce Samples By Headspace Gas Chromatography-Mass Spectrometry, Orhan Destanoğlu Apr 2024

Investigation Of Benzoic Acid And Sorbic Acid Concentrations In Tomato Paste, Pepper Paste, Ketchup, Mayonnaise, And Barbeque Sauce Samples By Headspace Gas Chromatography-Mass Spectrometry, Orhan Destanoğlu

Turkish Journal of Chemistry

In this study, it was aimed at investigating benzoic acid (BA) and sorbic acid (SoA) concentrations in tomato paste, pepper paste, ketchup, mayonnaise, and barbeque sauce samples by a validated static headspace gas chromatography–mass spectrometry (GC-MS) method. Salicylic acid (SalA) was used as internal standard and the measurements were conducted in the wide linear concentration ranges of BA and SoA which were 2.5–5000 and 12.5–5000, respectively. The limit of detections (LODs) were determined to be 1.5 and 4.5 mg/kg while the limit of quantifications (LOQs) were 2.5 and 12.5 mg/kg for BA and SoA, respectively. The average recovery% values of …


Phosphorus And Nitrogen-Containing Soybean Oil Polyols: Effect On The Mechanical Properties And Flame Retardancy Of Polyurethane Foam, Deni̇z Öztaşkin, Lütfullah Yusuf Yi̇vli̇k, İlayda Acaroğlu Degitz, Tarik Eren Apr 2024

Phosphorus And Nitrogen-Containing Soybean Oil Polyols: Effect On The Mechanical Properties And Flame Retardancy Of Polyurethane Foam, Deni̇z Öztaşkin, Lütfullah Yusuf Yi̇vli̇k, İlayda Acaroğlu Degitz, Tarik Eren

Turkish Journal of Chemistry

In recent years, there has been an increasing interest in producing new materials that use renewable resources and halogen-free flame retardants with nonleaching properties. This research focuses on designing and synthesizing phosphorus-nitrogen-based biopolyols for use in polyurethane (PU) foam production. Polyol (ESBO-DYM) with dual functionalities, renewability, and nonflammability is synthesized through the epoxy ring-opening reaction of epoxidized soybean oil with phosphorus and nitrogen-containing tetraol products (DYM). The mechanical and flame retardant properties of PU foams with the addition of an ESBO-DYM were investigated. Increasing the amount of phosphorus in the PU foams increased the thermal stability properties. Using 100% ESBO-DYM …