Turkish Journal of Chemistry最新文献

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.

In this study, we synthesized novel, economically efficient phosphonic acid-functionalized grafted sepiolite nanohybrids for selective elimination of copper ions from water. These nanohybrids were prepared by graft polymerization of glycidyl methacrylate onto sepiolite. We utilized free radical graft polymerization to graft glycidyl methacrylate (GMA) onto silanized sepiolite. The nanohybrids obtained exhibited a grafting percentage of 479% at 0.3 g of KPS initiator, 15% GMA monomer, and after 4 h of reaction. In pursuit of selectively removing metal ions from water, the nanohybrid with the highest grafting (PGE₃) was chemically treated with phosphoric acid to introduce phosphonic acid groups on it. FTIR, XRD, SEM, CHO analysis, BET, and TGA analysis were utilized to characterize the developed nanohybrids. Batch adsorption studies were carried out using AAS process, examining the impact of pH, adsorbent weight, contact time, adsorbate concentration, and temperature on the adsorption process. Due to the selectivity of phosphonic acid groups towards copper ions, phosphonic acid-functionalized grafted sepiolite nanohybrid (PGE₃-P) was used for copper ions removal from its aqueous solution. The maximum adsorption capacity of PGE₃-P adsorbents was 134.5 mg/g for copper ions. The data from kinetic studies suggests that the adsorption process of copper ions followed a pseudosecond-order model. Furthermore, Langmuir isotherm proved to be a more fitting model in equilibrium isothermal investigations. The thermodynamic analysis of the data indicates that the adsorption of copper ions by PGE₃-P is an endothermic and spontaneous process. The development of this phosphonic acid-functionalized grafted sepiolite nanohybrid adsorbent is a new contribution into the field of adsorption. The developed material can be utilized as selective adsorbent for elimination of other heavy metals from water.

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 (FTIR) and Ultraviolet-Visible Diffuse Reflectance Spectroscopy (UV-Vis DRS). The FTIR spectra of photoelectrode immersed in Zn-astaxanthin show peaks of C=O stretching and vibration -OH group at 1730 and 1273 cm^-1, respectively, and H-C-H stretching vibration with high intensity in 2939, 2923, and 2853 cm^-1. The UV-Vis DRS analysis shows the band gap of photoelectrode (PE), photoelectrode immersed in astaxanthin (PE/astaxanthin), and Zn-astaxanthin (PE/Zn-astaxanthin) are 3.19, 1.65, and 1.59 eV, respectively. Under illumination intensity of 300 W/m², the maximum energy conversion efficiency of DSSC with Zn-astaxanthin as sensitizer is (0.03 ± 0.0022)%, higher than DSSC with astaxanthin as sensitizer ((0.12 ± 0.0052)%). Up to 70 h of illumination, DSSC with Zn-astaxanthin as a sensitizer also has better stability than astaxanthin-based DSSC.

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 also involved designing new drugs and identifying necessary molecular scaffolds.

Pd (0) nanoparticles (NPs) distributed on lanthanum (III) oxide were ex situ generated from the reduction of Pd²⁺ ions using NaBH₄ as reducing agent. The Pd/La₂O₃ displayed good catalytic activity in H₂(g) releasing from the hydrazine-borane (HB) methanolysis reaction and it was identified by advanced techniques. Pd/La₂O₃ was found to be an active catalyst procuring three equiv. H₂(g) per mole of HB. The results from TEM images represent the formation of Pd (0) NPs with an average particle size of 1.94 ± 0.1 nm on the surface of La₂O₃. Moreover, Pd/La₂O₃ with various Pd loadings were prepared and tested as catalyst in the methanolysis reaction to find the optimum metal loading on La₂O₃ support. The highest H₂ formation rate was achieved with 3.0 wt% Pd. Pd/La₂O₃ catalyst exhibited a turnover frequency (TOF) value of 24.4 mol H₂ mol Pd^-1 min^-1 in the reaction conditions. Additionally, the effect of different catalyst concentrations and temperatures on the reaction kinetics for the methanolysis of HB catalyzed by Pd/La₂O₃.

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 Black B.

First- and second-generation hydroxyl-terminated dendrimers were prepared starting from a 1,3-diaminopropane core and sulfonimide linkers. A first-generation mesitylene-derived dendrimer was also prepared with the same terminals. The dendrimers were then reacted with Fe³⁺, Al³⁺, and UO₂²⁺ separately in order to apply the dendrimers for binding these metals, which have important industrial applications and pose environmental problems simultaneously. The prepared dendrimers were also shown to bind Fe³⁺ selectively from mixtures with Al³⁺.

Cinchona alkaloid-derived sulfonamides and ester dimers containing chiral hyperbranched polymers have been successfully synthesized and applied as catalysts in asymmetric reactions. Several hyperbranched polymers derived from cinchona alkaloids, incorporating sulfonamides and esters, were synthesized through Mizoroki-Heck coupling polymerization. These polymers were subsequently applied in enantioselective Michael addition reactions. As the prepared polymers are not soluble in frequently used organic solvents, they act as efficient catalysts in the enantioselective reaction of β-ketoesters to nitroolefins, achieving up to 99% enantioselectivity with good yields. The insoluble property allows them to better satisfy "green chemistry" requirements and be used several times without losing the enantioselectivity.

In recent years, water pollution caused by hazardous materials such as metals, drugs, pesticides, and insecticides has become a very serious environmental and health problem that needs to be addressed urgently. The nutritional needs associated with the increasing population also increase the demand for water use and rapidly increase the rate of freshwater consumption. Since most of the water in the universe is in the form of sea water, which cannot be directly used, freshwater resources are limited, compared to the existing available water. When addressing the purification of all kinds of pollution in environmental research, nanostructured membranes attract attention as alternative solutions for water treatment. Nanostructured membranes, which can be used for filtration and water treatment process, are summarized in recent research. Various types of nanostructured membranes are presented and used to remove salts and metallic ions in water treatment processes. The representations and application areas of these membrane systems are explained. Consequently, new water treatment nanostructured membranes that can be developed and their effective separation performances are described. The benefits of nanostructured membranes for water treatment and their progress in purification are discussed.