Publications

The potential of nanocomposite membranes (NCMs) prepared by the sodium alginate polymer and embedded with synthesized zeolitic imidazole framework-8 (ZIF-8) as fillers having microporous structure in the application of separation of gaseous mixture generated by the process of methane reforming was assessed. ZIF-8 crystals were created through hydrothermal synthesis, with sizes varying from 50 to 70 nm. NCMs were prepared with a 15% filler loading, i.e., synthesized ZIF-8. NCMs (ZIF-8) having H2 permeability of 28 Barrer and H2/CH4 selectivity of 125 outperformed neat polymer membranes in terms of separation performance at ambient temperature and 4 kg/cm2 pressure. The purity of H2 increased to as high as 95% among the measured values. The NCMs did not, however, outperform a neat polymer membrane in terms of their ability to separate mixtures of gases. Moreover, the combination of ZIF-8 as a filler with sodium alginate was new and had not been reported previously. As a result, it is worthwhile to investigate.

Abstract In this study, by using a co‐precipitation method MoO 3 /CuO/ZnO nanocomposite material was synthesized. Then the prepared material was fully characterized by using XRD (X‐ray diffraction), SEM (scanning electron microscopy), EDS (energy dispersive x‐ray spectroscopy), CV (cyclic voltammetry), and EIS (Electrochemical Impedance Spectroscopy). Zeta potential and hydrodynamic size were measured using a Zetasizer in PBS buffer. By using Scherrer's formula from XRD, particle size was determined which was around 26.5 nm. For the promising chemical sensor development, MoO 3 /CuO/ZnO nanocomposite material was fabricated onto a glassy carbon electrode (GCE) to provide a sensor probe with a fast response towards the selective hydrazine (HZ) toxin in phosphate buffer phase. The fabricated sensor probe is exhibited good sensitivity and long‐term stability as well as enhanced electrochemical performances. A calibration plot was found linear in the range of 0.2 nM to 2.0 mM (linear dynamic range, LDR) in presence of aqueous HZ solutions with highest sensitivity value and lower limit of detection and good limit of quantification (LOQ). This approach is promising as an efficient technique in developing a highly effective sensor probe with ternary metal oxides for detecting environmental pollutants on a broad scale.

A series of scarce fulleropyrrolines were synthesized via DMAP-mediated one-step reaction of [60]fullerene with commercially inexpensive aromatic aldehydes and arylmethanamines in the absence or presence of manganese(III) acetate. In the case of aminodiphenylmethane, novel 2,5,5-trisubstituted fulleropyrrolines could be easily obtained without the addition of manganese(III) acetate. As for arylmethanamines without α-substitutions, the addition of manganese(III) acetate was required to suppress the formation of fulleropyrrolidines, in order to generate the desired 2,5-disubstituted fulleropyrrolines. Two tautomers were produced as expected when different aryl groups (Ar¹ ≠ Ar²) from aromatic aldehydes and arylmethanamines were employed in the synthesis. A plausible reaction mechanism for the formation of fulleropyrrolines is proposed.

The influence of polymer, polyvinylpyrrolidone (PVP) on spectral properties of anionic azo dye, reactive yellow (RY) was investigated by UV–Vis spectroscopy in the temperature range of 298–313 K. The change in λmax and absorbance indicated the presence of interaction between anionic dyes and polymer. The binding constant (Kb) of complexation was determined from the Benesi–Hildebrand plot. The Kb value increased with increasing dye concentrations and decreased with the rise of the temperature. The values of ∆G° for RY–PVP complexation were found to be negative and these negative values reduce with the enhancement of temperature which indicates that the binding process is more spontaneous at lower temperature. The negative values of ΔS° and negative values of ΔH° refer a process which is always enthalpy dominated. Kb values showed significant change with the change of pH. The Kb value enhances with the rise of the carbon chain length of the alcohol and reduces with increasing percentages of alcohol. The Kb value decreases at higher electrolyte concentrations and also with the increase of the size of the anion of the electrolyte. The removal of dye from the waste water by the interaction of dye with polymer in the presence of surfactant and salt of higher concentration has also been studied.

Quantitative evaluation of the mechanical behavior of molecular materials by a nanoindentation technique has gained prominence recently. However, all the reported data have been on room-temperature properties despite many interesting phenomena observed in them with variations in temperature. In this paper, we report the results of nanoindentation experiments conducted as a function of temperature, T, between 283 and 343 K, on the major faces of three organic crystals: saccharin, sulfathiazole (form 2), and l-alanine, which are distinct in terms of the number and strength of intermolecular interactions in them. Results show that elastic modulus, E, and hardness, H, decrease markedly with increasing T. While E decreases linearly with T, the variations in H with T are not so, and were observed to drop by ∼50% over the range of T investigated. The slope of the linear fits to E vs T for the organic crystals was found to be around 1, which is considerably higher than the values of 0.3–0.5 reported in the literature for metallic, ionic, and covalently bonded crystalline materials. Possible implications of the observed remarkable changes in H for pharmaceutical manufacturing are highlighted.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Compounds having redox-active ferrocenyl groups have attracted considerable interest in several branches of Chemistry and Materials Science. Here we investigate a chalcone (compound I) having a ferrocenyl group which is further derivatized to pyrazoline to achieve a hybrid molecule having a ferrocenyl couple to a heterocyclic ring (compound II). These compounds were characterized using spectroscopic techniques including the (1H-NMR and 13C-NMR), UV-Visible and infrared (FT-IR) studies to confirm the structures and investigate the electronic properties of I and II. Furthermore, we confirmed the three-dimensional structures and any relevant interactions among the molecules in their unit cells using single crystal X-ray diffraction analysis. The molecules of both compounds stabilized by the C-H...halogen interactions, where Br acts as a halogen atom. Finally, the redox properties of I and II were accessed by cyclic voltammetry experiments. It is observed that the chalcone derivative has larger oxidation potential than the pyrazoline derivative.

The production of ammonia (NH₃) in the industrial scale basically relies on the traditional technology of Haber-Bosch, which is operated under harsh conditions with high energy consumption and a huge number of greenhouse gas emissions. Electrochemical N₂ reduction reaction (NRR) is a promising route for artificial N₂-to-NH₃ fixation with less energy consumption. However, an effective electrocatalyst, as a prerequisite of the NRR, is of significance. Here, we report that a spinel LiMn₂O₄ nanofiber acts as a noble-metal-free electrocatalyst for NH₃ synthesis with excellent performance under ambient conditions. The electrocatalyst, which was tested in 0.1 M HCl, has an excellent Faradaic efficiency of 7.44% and a NH₃ yield of 15.83 μg h^-1 mg_cat.^-1 at -0.50 V versus reversible hydrogen electrode. Moreover, it also possesses excellent electrochemical and structure stability.

Background: Cephalosporins are cornerstone β-lactam antibiotics arranged into five generations that progressively expand gram-negative activity while preserving gram-positive coverage across common and severe infections.Aim: To synthesize practice-oriented guidance on spectrum, mechanisms, pharmacokinetics, indications, safety, contraindications, monitoring, and toxicity.Methods: Narrative review of the supplied article integrating generational profiles, cefiderocol approvals, population-specific dosing, adverse effects, and stewardship themes.Results: First generation targets staphylococci/streptococci; second adds respiratory gram-negatives and anaerobes; third broadens Enterobacteriaceae with CNS penetration (ceftazidime provides antipseudomonal activity); fourth-generation cefepime adds β-lactamase stability and antipseudomonal activity; fifth-generation ceftaroline uniquely covers MRSA. Cefiderocol, a siderophore cephalosporin, is FDA-approved for complicated UTI and ventilator-associated pneumonia due to resistant gram-negative bacilli. Safety issues include hypersensitivity, drug-induced immune hemolytic anemia, N-methyl-thiotetrazole–associated hypoprothrombinemia and disulfiram-like reactions, and antibiotic-associated Clostridioides difficile colitis. Contraindications include cephalosporin allergy, anaphylaxis to β-lactams, and neonatal ceftriaxone in hyperbilirubinemia or with calcium. Monitoring focuses on renal function, PT/INR, and hemolysis labs; cefepime neurotoxicity is the hallmark of overdose, and careful dose adjustment in renal impairment is essential.Conclusion: Cephalosporins remain versatile and effective; optimal outcomes require tailored selection and stewardship, while cefiderocol extends options against carbapenem-resistant gram-negatives

Electrochemical N2-to-NH3 fixation under ambient conditions is emerging as a promising alternative to the energy-intensive and CO2-emitting Haber-Bosch process. However, this process involves difficulty in N2 activation, underlining the demand of electrocatalysts for the N2 reduction reaction (NRR). In this work, cubic sub-micron SnO2 particles on carbon cloth (SnO2/CC) are proposed as an efficient NRR electrocatalyst for ambient N2 conversion to NH3 with excellent selectivity. Electrochemical tests reveal that SnO2/CC attains a large NH3 yield of 1.47 × 10-10 mol s-1 cm-2 at -0.8 V vs. reversible hydrogen electrode (RHE) and a high Faradaic efficiency of 2.17% at -0.7 V vs. RHE in 0.1 M Na2SO4, outperforming most reported aqueous-based NRR electrocatalysts. Notably, it also shows strong electrochemical stability.