Chemical Papers最新文献

Keeping the principles of sustainability in view, this work explores the extraction of indene from pyrolysis oil—a complex by-product of the Ustyurt Gas-Chemical Complex—and its transformation into a novel cationite, highlighting sustainable approaches in chemical engineering and material science. Utilizing advanced analytical techniques, including thermogravimetric analysis (TG), chromato-mass spectrometry, and Fourier-transform infrared spectroscopy (FT-IR), indene was efficiently isolated and characterized. The indene extracted exhibited a principal ion peak at a molecular mass (m/z) of 117.0, confirming its purity and potential for further applications. Following extraction, indene underwent sulfonation and polycondensation with 35% formalin under specific conditions (100–110°C, 30–40 atm), resulting in a cationite with a yield of 71%. This synthesized IESA (indene-based sulfonated aromatic cation exchanger), demonstrated significant chemical–physical properties when compared to commercial equivalents, such as a moisture content significantly lower than the KU-2-8 (29.4% vs. 48–58%), and a dynamic exchange capacity (DEC) competitive with industry standards (472 mmol/m³ vs. 500–520 mmol/m³). The study not only showcases the potential of pyrolysis oil as a valuable feedstock for producing high-value chemical products, but also advances the development of new materials from industrial by-products.

The optically good quality organic 2-amino 4,6-dimethyl pyrimidine 4-nitrophenol (AMP4N) single crystal (length 120 mm and diameter 15 mm) was grown by immersed Sankaranarayanan–Ramasamy (ISR) method at ambient temperature using methanol as solvent. The ampoule was specially designed for the growth of good quality and bulk size unidirectional single crystal by slow cooling condition. The unwanted temperature gradient developed on the solution surface was completely avoided, hence the formation of secondary nucleation on top of the ampoule is avoided. The growth apparatus and optimization parameters have been made simpler compared to the conventional SR method. Growth direction parallel to the gravity direction can be easily achieved, hence slanted growth could be avoided within the ampoule and also linear transportation of embryos from solution to crystal–solution interface is achieved. The ISR method-grown single crystal was subjected to various characterizations. The structure of AMP4N was confirmed by single-crystal X-ray diffraction analysis. The optical behaviour of the grown crystal was analysed by UV–visible NIR spectrophotometer. Fourier transform infrared spectrum is used to confirm the functional groups present in the AMP4N crystal. The negative photoconductivity nature of the AMP4N single crystal was determined by photoconductivity analysis. The piezoelectric (d₃₃) coefficient has been measured, and the d₃₃ value shows that it is a suitable material for piezoelectric devices. The full-width at half maximum (FWHM) values of various regions indicate that the entire grown crystal has high crystalline perfection and is optically homogeneous. Birefringence interferometry shows that the grown crystal has good refractive index homogeneity. The novel crystal growth ISR method has been reported, and also various studies reveal that the ISR method-grown crystals are favourable for high performance optical device applications.

The negative environmental impact of fossil fuel and the ever-increasing need for renewable energy materials necessitate a rigorous search for optoelectronic materials. Photon reabsorption due to a small Stokes shift limits the light-emitting potentials of many optical materials. In this research, two benzimidazole Schiff bases, 3-(((1H-benzo[d]imidazol-2-yl)imino)methyl)phenol (1) and N-(1H-benzo[d]imidazole(-2-yl)-1-(3-nitrophenyl))methanimine (2), were synthesized via one-pot single-step condensation and characterized using spectrometric (¹H NMR, ¹³C NMR, HRMS and FTIR) techniques. The optoelectronic, nonlinear optical (NLO), adsorption properties and natural bond orbital (NBO) analysis of 1 and 2 were explored using spectroscopic, density functional theory (DFT) and Monte Carlo (MC) simulation approaches. The absorption, light-harvesting efficiency (LHE) and fluorescence properties were studied in solution. Static and dynamic first and second hyperpolarizabilities and parameters for power conversion efficiency (V_oc and ΔG_inj) were computed using the time-dependent DFT/B3LYP/6–311++G(d,p) method. Hyperpolarizabilities were compared with those of urea (standard). The binding properties of 1 and 2 on TiO₂ (anatase 101) were investigated using the MC method. The calculated electronic properties agree with the experimental results. The compounds display large Stokes shifts (> 200 nm), appreciable quantum yields and low band gaps. High LHE (87%) and large hyperpolarizabilities were obtained for 2. Dye 2 displayed a high V_oc, while 1 exhibited a more negative ΔG_inj. The negative adsorption energies of the 1-TiO₂ (− 52.9 kJ/mol) and 2-TiO₂ (– 57.1 kJ/mol) interfaces indicate their strong binding interactions with anatase. NBO analysis revealed that conjugation and hyperconjugation were the primary interactions responsible for the stabilization of the dyes. These dyes have the potential for use in optoelectronic and nonlinear optical applications.

The present investigation reports the environmentally benign, cost-effective approach to the fabrication of valuable ZnO NPs. In this green synthesis approach, the isolated extract of the lichen (permelia perleta) plays a pivotal role. A prominent absorption peak is displayed at 320 nm in the recorded UV spectra of the created nanomaterials. XRD analysis of the fabricated nanostructure expressed that the particle size was esteemed to be 30 nm. The SEM micrograph of the developed nanostructure depicted that most of them have spherical shape. Photocatalytic investigation result demonstrates that newly developed nanostructure photocatalyst removes both dye from the water sample effectively under UV light (310 nm) irradiation. The developed ZnO NPs removed acridine orange and eriochrome black-T with the efficiency of 87.8 and 82.3%, respectively, in 90 min of UV (310 nm) irradiation. Furthermore, the newly created nanostructure shows a significant antibacterial activity against tested microorganism. The highest antibacterial potential was exhibited against the E.coli.

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The present research is focused on elucidating the effect of the catalyst particle size during the hydro-co-processing of a mixture of Jatropha oil and fossil crude oil at initial pressure of 60 bar, 4 h of reaction time, stirring at 700 rpm; catalyst-to-feedstock ratio of 1:20 (wt:wt); and reaction temperatures from 360 to 390 °C. Hydrodesulfurization extent was determined by using ASTM D4294; hydrodeoxygenation was accounted for using Fourier transform infrared spectroscopy and H-nuclear magnetic resonance; while hydrocracking was evaluated by availing simulated distillation (ASTM D2887), and also electrospray ionization mass spectrometry followed by liquid bulk density (ASTM D4052). ASPEN HYSYS was employed to account for the distillable cuts. The powder sized catalyst exhibited the highest hydrodesulfurization activity at all temperatures showing the maximum conversion of 62.6% at 390 °C. Hydrodeoxygenation conversion was almost of 100% for reaction products as evidenced by disappearance of the FTIR bands at 1168 cm⁻¹, 1710 cm⁻¹, and 1743 cm⁻¹ and further confirmed by HRMN, independently of reaction temperature and particle size. Regarding hydrocracking, the light gas oil yield was about 40% for both sizes of the catalyst particles at the four reaction temperatures, and naphtha and kerosene increased as the temperature did, disregarding particle size.

We suggest sensor systems based on silver nanoparticles embedded within the polymethacrylate matrix for colorimetric determination of hydrogen peroxide. Polymethacrylate matrix stabilizes silver nanoparticles and its application enhances the selectivity of H₂O₂ determination through the transfer of the redox reaction from the solution volume into the solid phase, which reduces the access of interfering substances to the reaction medium. Dual-signal spectrophotometric and colorimetric approaches can be used for the determination of hydrogen peroxide in the range 0.2–4.4 mM with a detection limit 0.05 mM. We studied the conditions of interaction between the matrix components and some other substances by evaluating the influence of such factors as solution pH, the amount of nanoparticles within the polymer matrix, the contact time, and the analyte concentration upon the analytical signal.

In this study, a highly selective and sensitive composite electrochemical sensor based on an ion-imprinted polymer (IIP) material is reported for the potentiometric determination of ultra-trace copper (II) ions. The copper (II)-IIP was prepared by using N-methacryloyl-L-histidine chelating monomer and ethylene glycol dimethacrylate cross-linker via bulk polymerization method. The synthesized IIP was used as electroactive material (ionophore) with graphite (G) and paraffin oil (PO) for recognition of copper (II). The sensor composition was optimized for effective recognition of copper (II) by examining ratios of components used in sensor preparation. The sensor with a composition of IIP/G/PO in the ratio 30:50:20 (% w/w) exhibited an ultra-wide linear response in detection of copper (II) ions with a Nernstian slope of 32.8 ± 1.2 mV in the concentration range of 1.0 × 10^–8—1.0 × 10^–1 mol L⁻¹ (R² = 0.9978), and a response time of 6 s was achieved with the optimized sensor. The potential response was stable within the pH range from 3.0 to 8.0. The standard deviation of the sensor was below 1.2 mV for 1.0 × 10^–2, 1.0 × 10^–3, and 1.0 × 10^–4 mol L⁻¹ copper (II) solutions. The sensor afforded a highly selective potentiometric response to Cu²⁺ with respect to Rb⁺, K⁺, Li⁺, Na⁺, NH₄⁺, Cs⁺, Ba²⁺, Co²⁺, Mg²⁺, Zn²⁺, Ni²⁺, Pb²⁺, Cr³⁺, Sr²⁺, Al³⁺, and Ca²⁺ ions. The developed sensor was used as an indicator sensor for the potentiometric titrations of copper (II) with EDTA and successfully applied to the determination of copper (II) in tap water, river water, dam lake water samples, coin samples, and food supplements (multivitamin/multielement).

In the current study, montmorillonite and graphene oxide supported nanoscale zero-valent iron (Mt–nZVI–GO) composite was synthesized for the simultaneous elimination of tetracycline (TC) and cefixime (CFX) from aqueous environments. The fabricated adsorbent was characterized using different techniques, including scanning electron microscopy, energy dispersive X-ray, Fourier transform infrared spectroscopy, X-ray diffraction analysis, vibrating sample magnetometer, and Brunauer–Emmett–Teller analysis. The central composite design based on response surface methodology was applied to assay the effects of experimental variables, including pH (4–8), the adsorbent dosage (0.2–0.4 g/L), and contact time (10–30 min) for efficient simultaneous removal of TC/CFX. The optimal conditions at a pH of 4, adsorbent dosage of 0.4 g/L, and the contact time of 30 min resulted in 92.34% (actual) and 91.23% (predicted) removal. Eventually, the Mt–nZVI–GO nanocomposite can be an effective, inexpensive, and promising adsorbent for removing TC/CFX from wastewater of the hospital and pharmaceutical industry.

The mobile crystalline material-41 (MCM-41) has been used in various fields, such as measuring cations, dye removal, and drug delivery. Modification of MCM-41 improves some properties of mesoporous materials, including surface area, adsorption capacity, thermal stability, and mechanical stability. Considering of these, after synthesize of MCM-41@SiO₂-NH-pydc, in vivo and in vitro studies of MCM-41@SiO₂-NH-pydc were conducted. For in vitro toxicity, various concentrations of 75, 150, and 300 mg L⁻¹ were used in Allium cepa test to study the toxicity and genotoxicity of mesoporous. For in vivo toxicity, 40 Wistar albino rats were collected and acute toxicity was estimated through oral administration (PO). For the sub-chronic study, four groups of Wistar rats were randomly selected and received MCM-41@SiO₂-NH-pydc daily by gavage at dosages of 12.5, 25, and 50 mg kg⁻¹ for 28 days. For hematological and biochemical tests, blood was collected, and the liver and kidney were dissected and prepared as slides to study histopathology. The lethal dose 50 (LD₅₀) of MCM-41@SiO₂-NH-pydc was found to be more than 250 mg kg⁻¹. All hematological and biochemical parameters were reported as normal, indicating no serious toxicity. Therefore, based on the findings obtained, it is suggested to use MCM-41@SiO₂-NH-pydc as a safe, appropriate, and novel carrier for drug delivery investigations.

Methanol to olefins (MTO) is an important technology for the production of ethylene and propylene, which does not rely on the petroleum resources. A mathematical model was established for the Sinopec MTO reactor, and the kinetic parameters were optimized based on actual industrial operation data. The validation results showed that the calculated values matched well with the actual values. To better simulate the actual production conditions, the reactor model was integrated with the regenerator model. Sensitivity analysis and optimization calculation showed that adjusting the inlet temperature, pressure and catalyst transportation flow rate of the MTO reactor is more effective for improving the selectivity of main products.