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Articles 1 - 11 of 11
Full-Text Articles in Physical Sciences and Mathematics
Graphene Aerogels: Part 1 - Derived From Graphene Oxide And Thermally Reduced Graphene Oxide Via Supercritical Carbon Dioxide Drying, Meryem Samanci, Ayşe Bayrakçeken
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 …
Ultrasound-Assisted Synthesis Of Rgo/Sio2-Based Nanosheets And Their Electrochemical Performances In Li-Ion Batteries, Ersu Lökçü, Süleyman Can, Mustafa Anik
Ultrasound-Assisted Synthesis Of Rgo/Sio2-Based Nanosheets And Their Electrochemical Performances In Li-Ion Batteries, Ersu Lökçü, Süleyman Can, Mustafa Anik
Turkish Journal of Chemistry
In this study, a facile approach has been developed to fabricate GO/SiO2 nanosheets by the hydrolysis of tetraethyl orthosilicate (TEOS) in the graphene oxide (GO) solution with the assistance of the ultrasonication. The morphology and structure of the SiO2/GO nanosheets were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) and Raman spectroscopy. The results showed that the covalently bonded SiO2 nanoparticles onto the GO sheets were dense and uniform. The agglomeration of the nanosheets was prevented by the ultrasonication and the layer sizes decreased throughout the synthesis process. The size and thickness of the SiO2 …
Investigation Of Boron Adsorption By Graphene Oxide: Equilibrium, Kinetic, And Thermodynamic Studies, Mehmet Fati̇h Önen, Nalan Erdöl Aydin, Osman Eksi̇k, Peli̇n Demi̇rci̇vi̇, Gülhayat Saygili
Investigation Of Boron Adsorption By Graphene Oxide: Equilibrium, Kinetic, And Thermodynamic Studies, Mehmet Fati̇h Önen, Nalan Erdöl Aydin, Osman Eksi̇k, Peli̇n Demi̇rci̇vi̇, Gülhayat Saygili
Turkish Journal of Chemistry
Graphene oxide, which has a great application in industry, is one of the promising carbonous materials. Modified Hummers method was applied to synthesize graphene oxide. Characterization techniques showed that pure graphene oxide was successfully obtained. Its adsorptive properties were investigated by boron adsorption. The results were demonstrated that boron adsorption on graphene oxide was a pH-dependent process and maximum adsorption was achieved at pH 6 (0.98 mg g?1). Langmuir adsorption capacity was calculated as 3.92 mg g?1 with R2 = 0.99. The kinetic data brought to light that pseudosecond-order kinetic model was well described the experimental data (R2 = 0.99), …
Electrically Conductive, Hydrophobic, Uv Protective And Lightweight Cotton Spunlace Nonwoven Fabric Coated With Reduced Graphene Oxide, Beki̇r Cenkkut Gülteki̇n
Electrically Conductive, Hydrophobic, Uv Protective And Lightweight Cotton Spunlace Nonwoven Fabric Coated With Reduced Graphene Oxide, Beki̇r Cenkkut Gülteki̇n
Turkish Journal of Chemistry
In this study, cotton spunlace nonwoven fabrics with four different basis weights were coated with graphene oxide (GO) by conventional dip coating method which is one of the most simple and effortless process in textile industry. The graphene oxide coated cotton nonwoven fabrics were immersed in an aqueous sodium dithionite solution in order to obtain reduced graphene oxide (RGO) coated cotton spunlace nonwoven fabrics. The obtained nonwoven fabrics became electrically conductive with very low surface electrical resistivity of 5.98 × 102 W/sq for the 70 g/m2 basis weight nonwoven fabric. The color measurements and reflectance spectrophotometry were performed in order …
Amin-Modified Graphene Oxide As A Promising Adsorbent For Selective Extraction Of Dexamethasone Adulterant From Herbal Supplements, Mahboob Nemati, Ali Zayer, Samin Hamidi
Amin-Modified Graphene Oxide As A Promising Adsorbent For Selective Extraction Of Dexamethasone Adulterant From Herbal Supplements, Mahboob Nemati, Ali Zayer, Samin Hamidi
Turkish Journal of Chemistry
In most cases, herbal supplements found in illegal centers and herbal medicine stores have harmful content that causes irreparable damage to people. As a representative of the green chemistry method, a rapid and efficient dispersive micro solid-phase extraction (D-mSPE) method was applied to extract dexamethasone adulterant from handmade supplements sold as power natural enhancing materials. The quantification of the analyte was performed by high performance liquid chromatography with an ultraviolet detector. Effective parameters on the extraction recovery, including the type and amount of adsorbent, the kind of elution solvent, and the time of extraction and elution, were systematically investigated. The …
Graphene Preparation And Graphite Exfoliation, Ahmed Moosa, Mayyadah Abed
Graphene Preparation And Graphite Exfoliation, Ahmed Moosa, Mayyadah Abed
Turkish Journal of Chemistry
The synthesis of Graphene is critical to achieving its functions in practical applications. Different methods have been used to synthesis graphene, but graphite exfoliation is considered the simplest way to produce graphene and graphene oxide. In general, con-trolling the synthesis conditions to achieving the optimum yield, keeping the pristine structure to realize on-demand properties, mini-mum layers with the smallest lateral size, and minimum oxygen content are the most obstacles experienced by researchers. Each applica¬tion requires a specific graphene model, graphene oxides GO, or even graphene intercalated compounds (GIC) depending on synthesis conditions and approach. This paper reviewed and summarized the …
Uv-Visible Spectroscopic Study On Multi-Staged Film Formation Mechanisms Of Graphene Oxide-Doped Polystyrene Latex (Ps Latex/Go) Nanocomposites, Asef Etemadi, Bariş Demi̇rbay, Şazi̇ye Uğur
Uv-Visible Spectroscopic Study On Multi-Staged Film Formation Mechanisms Of Graphene Oxide-Doped Polystyrene Latex (Ps Latex/Go) Nanocomposites, Asef Etemadi, Bariş Demi̇rbay, Şazi̇ye Uğur
Turkish Journal of Chemistry
We report the effect of graphene oxide (GO) on film formation and morphological properties of GO-doped polystyrene (PS) latex nanocomposite (PS latex/GO) films using UV-visible absorption spectroscopy and scanning electron microscopy (SEM). PS latex particles were synthesized through emulsion polymerization technique and then nanocomposite blends, each containing different concentrations of GO ranging from 0 wt% to 70 wt%, were obtained. Prepared blends were deposited on glass plates via drop-casting method and coated substrates were annealed at different temperatures between 100 °C and 250 °C. At each annealing temperature, transmitted light intensity of nanocomposite films was recorded. Void closure and Prager-Tirrell …
Ionic Liquid-Based Graphene Oxide-Coated Fiber For Headspace-Solid Phase Microextraction Of Polycyclic Aromatic Hydrocarbons In Water Samples, Peli̇n Erdem, Paniz Tashakkori, Melek Merdi̇van, Serap Seyhan Bozkurt
Ionic Liquid-Based Graphene Oxide-Coated Fiber For Headspace-Solid Phase Microextraction Of Polycyclic Aromatic Hydrocarbons In Water Samples, Peli̇n Erdem, Paniz Tashakkori, Melek Merdi̇van, Serap Seyhan Bozkurt
Turkish Journal of Chemistry
Ionic liquid (IL) containing amino and vinyl terminated imidazolium cation and bis[(trifluoromethyl)sulfonyl] imide anion-functionalized graphene oxide (GO) coating material was prepared and coated on a stainless steel wire by a sol-gel technique for headspace-solid phase microextraction (HS-SPME). Its extraction performance was checked by HS-SPME of polycyclic aromatic hydrocarbons (PAHs) coupled to gas chromatography with mass spectrometry (GC-MS). The extraction capability of the IL-functionalized GO-coated fiber was comparable with that of the commercial fibers of polydimethylsiloxane (PDMS) and polydimethylsiloxane/carboxen/divinylbenzene (PDMS/CAR/DVB). Under the optimized conditions, such as extraction temperature, extraction time, and salting-out, the proposed HS-SPME-GC-MS method presented a wide working range …
The Effect Of Starting Material Types On The Structure Of Graphene Oxide And Graphene, Fi̇li̇z Boran, Sevi̇l Çeti̇nkaya Gürer
The Effect Of Starting Material Types On The Structure Of Graphene Oxide And Graphene, Fi̇li̇z Boran, Sevi̇l Çeti̇nkaya Gürer
Turkish Journal of Chemistry
In this study, the effects of starting material types on graphene oxide (GO) are reported with the aim of developing graphene (GR) synthesis. The GOs were prepared from natural graphite (NG) powder and graphite nanoplate (GNp) based on the Hummers method. Two kinds of GR were successfully synthesized using GOs, which were prepared from NG and GNp in the presence of hydrazine and ammonia for 24 h at a 100 $^{\circ}$C reaction temperature. The synthesized GOs and GRs were characterized by X-ray diffraction (XRD) techniques, Fourier transform infrared, high-contrast transmission electron microscopy (HCTEM), dispersive Raman spectroscopic analyses, and elemental analyses. …
Physicochemical Characterization Of Different Cellulose Polymorphs/Graphene Oxide Composites And Their Antibacterial Activity, Sherif Mohamed Abdel Salam Keshk, Ibrahim Sayed Yahia
Physicochemical Characterization Of Different Cellulose Polymorphs/Graphene Oxide Composites And Their Antibacterial Activity, Sherif Mohamed Abdel Salam Keshk, Ibrahim Sayed Yahia
Turkish Journal of Chemistry
In order to investigate the interaction of graphene oxide (GO) with different cellulose polymorphs (I and II), we synthesized cellulose (I and II)/GO composites using the sonication method. Interestingly, no new peaks were observed in the FT-IR pattern of the cellulose (I and II)/GO composites, indicating that no chemical reactions took place between GO and cellulose. The X-ray diffraction patterns of cellulose I and II/GO composites were slightly different than those observed for cellulose I and II, indicating that some physical interactions occurred between the GO and cellulose. Unexpectedly the $d$-spacing values and the diffraction plane at the high-angle side …
Graphene Oxide--Magnetite Nanocomposite As An Efficient And Magnetically Separable Adsorbent For Methylene Blue Removal From Aqueous Solution, Kadem Meral, Önder Meti̇n
Graphene Oxide--Magnetite Nanocomposite As An Efficient And Magnetically Separable Adsorbent For Methylene Blue Removal From Aqueous Solution, Kadem Meral, Önder Meti̇n
Turkish Journal of Chemistry
We report a facile method to produce a magnetically separable graphene oxide--magnetite nanocomposite (GO--Fe_3O_4) and its adsorption performance in methylene blue (MB) removal from aqueous solution. The GO--Fe_3O_4 nanocomposite was synthesized by a solution-phase self-assembly method including the incorporation of monodisperse Fe_3O_4 nanoparticles (NPs) and GO in a dimethylformamide/chloroform mixture under sonication. The successfully decorating GO sheet with monodisperse Fe_3O_4 NPs was proved by TEM study. ICP--OES data of the GO--Fe_3O_4 nanocomposite show that the GO--Fe_3O_4 nanocomposite consists of 21 wt% Fe_3O_4 NPs, which is sufficient for its magnetic separation from aqueous solution. The spectroscopic studies reveal that the GO--Fe_3O_4 …