Turkish Journal of Chemistry最新文献

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 structurally compared with GR, RGO, and carbon aerogel (CA) without graphene-based materials. Physical characterizations (Brunauer, Emmett, and Teller (BET) analysis, scanning electron microscope-energy dispersive X-ray (SEM-EDX) analysis, micro-Raman spectroscopy, X-ray diffractometer (XRD) were made to examine the structural properties of GAs. In order to analyze the behavior of the surfaces of the synthesized materials against electrochemical corrosion, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) analyses were performed. As a result of the electrochemical corrosion process of the synthesized materials, the change in their specific capacitance and the formation of pseudocapacitive charge on the surfaces were examined.

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 synthesized poly(HEMA-MATyr) microbeads adsorbent was investigated at different initial concentrations, different temperatures, and adsorption times. The maximum adsorption capacity of microbeads was determined as 56.67 mg/g at a concentration of 2.5 mg/L. The amount of cholesterol adsorbed in the IMS was found as 83.07 mg/g polymer, which indicates that 92% of the cholesterol in the medium was adsorbed. The selectivity behavior of the cholesterol imprinted polymer was carried out with the stigmasterol and estradiol molecules, which are similar in structure, molecular weight, and character to the cholesterol molecule. The chol-imprinted polymeric beads were 21.38 and 10.08 fold more selective for cholesterol compared to estradiol and stigmasterol steroids used as competitor agents respectively. Kinetic and isotherm calculations of the synthesized cholesterol imprinted polymer were made and reusability experiments were carried out.

In this study, arylglyoxals, acetylacetone, and 2,6-dimethyl phenol or 2,6-di-tert-butyl phenol are combined to efficiently synthesize a series of 1-(4-(3,5-dialkylphenyl)-2-methyl-5-phenylfuran-3-yl) ethan-1-one derivatives in excellent yields. These reactions were carried out in acetone at reflux under catalyst-free conditions in the presence of triethylamine as a base for 3 h. NMR, FT-IR, EI-MS, and elemental studies were used to characterize the products' structural characteristics. The present study has also several benefits, such as excellent yields and the ease of workup procedure, making it an appealing, practical, and acceptable one-pot method for producing functionalized derivatives of dialkyl furan.

In this study, a novel adsorbent material, poly (2-hydroxyethyl methacrylate-co-N-isopropyl acrylamide) (p(HEMA-co-NIPAM) hydrogel, was synthesized for the purpose of removing methylene blue (MB) from aqueous media. The synthesis of hydrogel was carefully conducted, and its properties were thoroughly examined using techniques such as Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). The adsorption experiments conducted revealed a remarkable affinity of p(HEMA-co-NIPAM) hydrogel towards MB. The highest adsorption was observed when 0.05 g of the adsorbent were utilized, with optimal conditions at a pH of 6.0 and a temperature of 15 °C. This underscores the importance of pH control and temperature regulation in optimizing the adsorption treatment. The adsorption behavior of MB on p(HEMA-co-NIPAM) hydrogel was best elucidated by the Langmuir isotherm model, which provided insights into the maximum adsorption capacity. Impressively, this capacity reached 126.6 mg/g, indicative of the adsorbent's robust capability to capture the MB molecules. The isotherm data further highlighted the strong affinity between p(HEMA-co-NIPAM) hydrogel and the MB dye, underscoring the effectiveness of the synthesized hydrogel as an adsorbent material. The successful application of p(HEMA-co-NIPAM) hydrogel for MB adsorption not only emphasizes its potential for wastewater treatment but also hints at its broader significance for environmental remediation. By harnessing the adsorption capabilities of this hydrogel, the removal of MB from industrial and domestic wastewater could be significantly enhanced, leading to cleaner water resources. This study presents p(HEMA-co-NIPAM) hydrogel as a promising adsorbent material with exceptional affinity for MB. This is demonstrated through a comprehensive analysis of its synthesis, characterization, and adsorption performance. The findings hold promise for addressing wastewater contamination issues and promoting sustainable water management practices.

Breast cancer is one of the most common types of cancer worldwide and has the most lethality ratio for females among all cancers. Although current cancer therapeutics have made considerable advancements, there is still room for improvement in terms of efficacy. Many anticancer drugs have a risk of causing serious adverse effects due to their nonspecific cytotoxic effects on both tumor and healthy cells. New therapeutics might have a greater ability to kill cancer cells, reduce the volume of tumors, and improve overall therapy response rates. Herein, we report the efficient synthesis and characterization of three amphi vic-dioximes and their six novel mono-, which are extremely rare in platinum chemistry, and bisplatinum(II) complexes for breast cancer treatment. Antitumoral activities of Pt(II) complexes have been investigated on CCD-1079Sk healthy fibroblast cell line, MCF-7 and MDA-MB-231 human breast cancer cell lines. Cytotoxicity, cell cycle, and apoptotic assays were performed. All new Pt(II) complexes exhibited selective antiproliferative effects on breast cancer cells by showing less cytotoxicity to healthy cells than known anticancer drugs cisplatin and bicalutamide. In vitro studies show that these new Pt complexes have high anticancer and antiproliferative effects and may be new alternatives to existing anticancer drugs.

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 BA and SoA were found to be 98.5% and 98.7% in an open tomato paste sample while these values were 98.7% and 100.3% in a mayonnaise sample, respectively. Accuracy of the proposed method was confirmed by statistically (significance test) evaluating excellent recovery values. In real samples, while the results of the canned tomato pastes and industrial sauce samples were found suitable, BA and SoA ​​were determined in some tomato and pepper paste products sold under the traditional or homemade name although use of the preservatives in the pastes were prohibited. It is vital for public health to prevent adulteration in pastes which is indispensable for Turkish cuisine as well as prevalently consumed in the world. Therefore, the proposed method can be used in food control laboratories due to its reliability and consumption of much less toxic chemical reagents.

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 as a polyol in the foam formulation increased the limiting oxygen index (LOI) value to 22.9% and resulted in the highest char yield according to the thermal gravimetric analysis (17% at 600 °C). Additionally, the introduction of ESBO-DYM polyol into the formulation resulted in a decrease in the compression strength of the foams. The foam density decreased as the amount of ESBO-DYM polyol in the formulation increased. The foam with the highest amount of ESBO-DYM had a foam density of 29.1 kg/m³. The morphology of the foams was characterized using a scanning electron microscope (SEM). As a result of this study, flame retardant polyurethane foams were formulated using a renewable source, polyol, along with commercial compounds.

The purpose of this study was the polymerization of carbazole (Cz), pyrrole (Py) and copolymerization of them onto polyester (PES) textile with chemical oxidative method by using FeCl₃. First, in order to determine the optimum conditions, the effect of polymerization steps, the immersion order of the PES to the oxidant and monomer solutions, time, monomer, oxidant, and surfactant concentrations and types on the conductivities of PES/PCz composite were investigated and at this conditions, conductive composite, PES/P[Py-co-Cz] was obtained. The highest conductivities were obtained as 12.4 mS/cm and 9.0 mS/cm for PES/PCz and PES/P[Py-co-Cz], respectively. Further characterization of PES/P[Py-co-Cz] was performed by conductivity, FTIR, scanning electron microscopy (SEM), and dynamic mechanical analysis (DMA) measurements, and results were compared with PES/PCz and also PES/PPy. The presence of Py and Cz in the same polymer chain created synergy and improved the conductivity and mechanical properties of the composite.

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 0.65-14 μg.ml^-1 at optimum conditions. LOD and LOQ values were calculated as 0.1 and 0.35 μg.ml^-1, respectively. The proposed method was used for the determination of SY in different type of powder drinks. The developed nanosensor is environmentally friendly, easy, fast, reproducible, and low cost.

Polyvinyl alcohol (PVA)-starch-based bioplastics are widely used in many applications. pH-responsive plastic packaging was produced through the incorporation of senggani (Melastoma malabathricum Linn.) fruit extract into PVA-taro starch-based plastic packaging. The objective of this research was to examine the characteristics of senggani fruit extract under different pH conditions and explore its application as a pH indicator in intelligent packaging. The senggani fruit was extracted through the maceration method using a solvent comprising 96% ethanol and 3% citric acid, with a ratio of 85:15 (v/v). The senggani fruit extract solution underwent color changes, appearing pink at pH levels below 6, pale purple at pH 7-11, and brownish-yellow at pH 12-14. Notably, the color of the senggani fruit extract solution remained stable at pH < 5. Before the addition of the senggani fruit extract, the PVA-taro starch solution produced a brownish-yellow plastic packaging. However, following the addition of senggani fruit extract, the plastic packaging turned pink. The addition of senggani fruit extract affected the mechanical properties of plastic packaging, resulting in a reduction in swelling from 103.679 ± 2.456% to 57.827 ± 3.563%, a decrease in tensile strength value from 3.827 ± 0.603 Mpa to 1.991 ± 0.460 Mpa, and a decline in the percent elongation value from 156.250 ± 12.392% to 116 ± 6.722%. Plastic packaging incorporating senggani fruit extract exhibits color changes across the pH range of 1-14, accompanied by varying color parameter values (L, a, b, E, and WI). Therefore, it has the potential to be used as intelligent packaging for monitoring food freshness and quality.