Publications

Spectroscopic Analysis of Au-Cu Alloy Nanoparticles of Various Compositions Synthesized by a Chemical Reduction Method

Au-Cu alloy nanoparticles were synthesized by a chemical reduction method. Five samples having different compositions of Au and Cu (Au-Cu 3 : 1, Au-Cu 2 : 1, Au-Cu 1 : 1, Au-Cu 1 : 2, and Au-Cu 1 : 3) were prepared. The newly synthesized nanoparticles were characterized by electronic absorption, fluorescence, and X-ray diffraction spectroscopy (XRD). These alloy nanoparticles were also analyzed by SEM and TEM. The particle size was determined by SEM and TEM and calculated by Debye Scherrer’s equation as well. The results revealed that the average diameter of nanoparticles gets lowered from 80 to 65 nm as the amount of Cu is increased in alloy nanoparticles. Some physical properties were found to change with change in molar composition of Au and Cu. Most of the properties showed optimum values for Au-Cu alloy nanoparticles of 1 : 3. Cu in Au-Cu alloy caused decrease in the intensity of the emission peak and acted as a quencher. The fluorescence data was utilized for the evaluation of number of binding sites, total number of atoms in alloy nanoparticle, binding constant, and free energy of binding while morphology was deduced from SEM and TEM.

All-inorganic perovskite quantum dots CsPbX3 (Br/I) for highly sensitive and selective detection of explosive picric acid

Preface

CCDC 845478: Experimental Crystal Structure Determination

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.

Synthesis of novel steroidal oxazolo quinoxaline as antibacterial agents

Steroidal[oxazolo(4,5-b)quinoxaline-2-yl-hydrazone] derivative (7a–9a) (7b–9b) were prepared by the multi-step reactions of steroid. It is prepared via the reaction of steroidal semicarbazones with 2,3-dichloroquinoxaline at 80 °C in ethanol. The structures of the compounds were evident by IR, 1H NMR and mass spectrometry and their purities were confirmed by elemental analyses. The antibacterial activity of these compounds was evaluated by the disk diffusion assay against two Gram-positive and two Gram-negative bacteria and then the minimum inhibitory concentration (MIC) of compounds was determined. The results showed that compounds (7a, 7b, 8a, 8b) are better antibacterial agent as compared with the standard drug amoxicillin.

Comparative performances of phenolic sensors based on various CeO₂-carbon material nanocomposites for environmental safety

Purpose The purpose of this study is to prepare various CeO 2 -based carbon material (CNT, CB, GO) nanocomposites through a wet chemical process for the development of a sensor probe to detect various environmental toxins by using an electrochemical approach under room temperature conditions. A comparative study on sensitive and selective phenolic sensor (4-methoxyphenol; 4-MP) has been fabricated by modifying a glassy carbon electrode (GCE) with various nanocomposites (NCs) such as CeO 2 , CeO 2 –CNT (carbon nanotubes), CeO 2 –CB (carbon black) and CeO 2 –GO (graphene oxide) NCs. Design/methodology/approach The CeO 2 –CNT NCs were prepared by the wet chemical method at low temperature. NCs were characterized by various methods such as transmission electron microscopy (TEM), Fourier-transform infra-red (FTIR), ultra-violet/visible (UV-Vis) spectroscopy and XRD (X-ray diffraction). CeO 2 –CNT NCs were immobilized as a film on the flat surface of the GCE by using binders (5% Nafion). The electrochemical measurements of the 4-MP detection with the CeO 2 –CNT NCs/Nafion/GCE sensor were studied by the current-voltage method. Findings In the optimal conditions, the sensitivity, detection limit and limit of quantification of 4-MP sensor probe were found to be 47.56 µAcm-2 µM −1 , 12.0 ± 0.2 nM and 40.0 ± 0.5 nM (S/N of 3), respectively. Research limitations/implications This electrochemical sensor showed an acceptable analytical performance in the detection of 4-MP with higher sensitivity, lower detection limit, large dynamic concentration range, good reproducibility and fast response time. Practical implications This electrochemical approach can be applied practically for the determination of selective 4-MP in real environmental and extracted samples. Social implications CeO 2 –CNT NCs/Nafion/GCE sensor probe was used for the safety of environmental and health-care fields at larger scales. Originality/value This electrochemical approach is a significant achievement on the development of sensor probe. The results are indicated as being technically detailed with an up-to-date account of recent chemical sensor research studies.

Ethyl (2<i>E</i>)-2-cyano-3-(1-methyl-1<i>H</i>-pyrrol-2-yl)prop-2-enoate

The 15 non-H atoms of the title compound, C(11)H(12)N(2)O(2), are approximately coplanar, the r.m.s. deviation being 0.145 Å. The major deviation from coplanarity is seen in a twist between the ethene (E configuration) and pyrrole rings [C-C-N-C torsion angle = -8.26 (18)°]. The carbonyl O and cyano N atoms are syn to each other. In the crystal, supra-molecular linear tapes linked by C-H⋯O and C-H⋯N inter-actions are further connected by C-H⋯π(pyrrole) inter-actions.

Mixed Micellization of Gemini Surfactant with Nonionic Surfactant in Aqueous Media: A Fluorometric Study

2-{(<i>E</i>)-[(2<i>Z</i>)-(3-Chloro-1-methyl-2,2-dioxo-3,4-dihydro-1<i>H</i>-2,1-benzothiazin-4-ylidene)hydrazinylidene]methyl}phenol

In the title compound, C(16)H(14)ClN(3)O(3)S, the thia-zine ring adopts a sofa (half-chair) conformation, with an r.m.s. deviation from the mean plane of 0.23 Å. The S atom and S-bonded C atom exhibit the maximum deviations from the thia-zine mean plane [-0.3976 (12) and 0.3179 (14) Å, respectively]. The conformations around the double bonds in the R(2)C=N-N=CHR unit are Z and E. An intra-molecular O-H⋯N hydrogen bond with the hy-droxy group as donor generates an S(6) ring motif. In the crystal, pairs of weak C-H⋯O inter-actions connect the mol-ecules, forming inversion dimers.

New Polyamides and Polyoxazoles Based on Diphenyl Ether Segments in the Polymers' Backbone

Two new series of polyamides, 7 a-e and polyoxazoles 8 a-e , containing diphenyl ether segments were synthesized using a low-temperature solution of polycondensation and polycyclization reactions, respectively. Polyamides were synthesized by interaction of monomer 4 with different aliphatic and aromatic diacid chlorides, including adipoyl, sebacoyl, oxaloyl, 4,4′-azodibenzoyl and 3,3′-azodibenzoyl dichlorides. The poly-merization reaction was carried out in dry DMF as a solvent and in the presence of anhydrous potassium carbonate as a catalyst at room temperature. Polyoxazoles were obtained as cyclization products form corresponding polyamides in polyphosphoric acid. The model compounds 5 and 6 were synthesized to know the optimum polymerization procedures. The structure of the model compounds as well as the resulting polymers was characterized by elemental and spectral analyses. The synthesized polymers were soluble in protonic solvents such as formic and concentrated sulfuric giving different colors. The thermal properties of those polymers were evaluated by TGA, DTG, and DTA measurements and correlated to their structural units. FDT for polyamides was nearly complete at around 730–750°C, while for polyoxazoles it was nearly complete at around 580–650°C. The glass transition temperatures for the selected polymers were in the range of 47–74°C, while T m values were in the range of 156–315°C. X-ray analysis showed that the selected polyamides have a higher degree of crystallinity than polyoxazoles in the region 2θ = 5−60°. In addition, the morphological properties of selected examples were tested by SEM measurements. A comparative SEM study was carried out between selected polyamides and polyoxazoles.

CCDC 1063027: Experimental Crystal Structure Determination

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.

Synthesis of aluminum pyrophosphate for efficient sorption of U(VI)

A synergistic biosorption and biomineralization strategy for Kocuria sp. to immobilizing U(VI) from aqueous solution

Aloe Vera Rind Nanofibers: Effect of Isolation Process on the Tensile Properties of Nanofibre Films

To improve the properties of bio-oil, a new method was proposed that does not involve introduction of any energy medium. An ether-soluble fraction (ES), a dichloromethane soluble fraction (DCMS), and a dichloromethane insoluble fraction (DCMIS) of bio-oil were obtained using ether and dichloromethane as extraction solvents. The same amount of each fraction (10 g) was blended into bio-oil with a certain quantity of 100 g. The three samples were then placed in sealed vials and heated for 12, 60, and 180 h at both 60 C and 80 C in an oil bath. Based on the aging properties of the three fractions, blended bio-oil was prepared using ES and DCMS in certain volume ratio. The total yield of the three fractions combined was around 90 wt%; the weight loss was thought to be due to the volatilization of low molecular weight matter and water during the process of solvent evaporation using a rotary evaporator. The aging test results indicated that the DCMIS fraction had the poorest properties compared with ES and DCMS such as acid number, water content and viscosity. In order to get the best properties of blended bio-oil, the optimal volume ratio of ES/DCMS was 1/2 according to the aging test.

Cadmium oxide based efficient electrocatalyst for hydrogen peroxide sensing and water oxidation

Plant-mediated fabrication of plasmonic-magnetic Ag-Fe ₃ O ₄ nanocomposites for broad-spectrum photocatalytic wastewater treatment

This study presents a sustainable, green synthesis of silver-coated magnetite nanocomposites (Ag-Fe3O4) using Brachychiton populneus leaf extract, aiming to develop an efficient and reusable photocatalyst for wastewater treatment. The nanocomposites combine the visible-light plasmonic activity of silver nanoparticles (AgNPs) with the magnetic recovery capability of Fe3O4, resulting in a multifunctional hybrid material. Comprehensive characterization using XRD, SEM, EDX, FTIR, UV–Vis spectroscopy, BET surface area analysis, and VSM confirmed successful formation of Ag-Fe3O4 with a mesoporous structure, uniform particle distribution, reduced bandgap (1.95 eV), and strong magnetic properties. The photocatalytic performance was evaluated by the degradation of methylene blue (MB) and Congo red (CR) under visible light. The composite demonstrated superior photocatalytic efficiency, achieving 97% and 92% degradation of MB and CR (20 ppm), respectively, within 30 min, significantly outperforming individual AgNPs and Fe3O4. Kinetic studies confirmed pseudo-first-order reaction behavior. The enhanced activity was attributed to the synergistic effect of Ag and Fe3O4, which improved light absorption, interfacial charge separation, and reactive oxygen species (ROS) generation. This work highlights the potential of green-synthesized Ag-Fe3O4 as a highly efficient, magnetically recoverable, and environmentally friendly photocatalyst for wastewater remediation applications.

Exploring the effect of organic–inorganic additives loaded on modified polyethersulfone membranes

ABSTRACT In this work, a novel modified polyethersulfone (PES) membrane was made by blending PES with organic biomolecules which were N 1 , N 4 ‐bis(4‐sulfamoylphenyl)terephthalamide (SF), and N 1 , N 4 ‐bis[4‐( N ‐(5‐methylisoxazol‐3‐yl)sulfamoyl)phenyl]terephthalamide (SZ) to afford PES‐SF and PES‐SZ membranes. Antifouling properties of these modified membranes were examined against different types of bacteria and a fungus as well as by measuring the contact angle. The results showed the addition of these organic additives to PES membranes did not improve the hydrophilicity and exhibit any microbial activity. Thus, Cu 2 O nanoparticles were used with different concentrations to afford PES‐SF‐Cu 2 O and PES‐SZ‐Cu 2 O nanocomposites membranes. The results showed when Cu 2 O nanoparticles (3 wt %) was added to PES‐SF 3 and PES‐SZ 3 membranes, both membranes showed the best hydrophilicity with 67° for PES‐SF 3 ‐Cu 2 O membrane and 77° for PES‐SZ 3 ‐Cu 2 O membranes. PES‐SF 3 ‐Cu 2 O and PES‐SZ 3 ‐Cu 2 O membranes showed antibacterial against Pseudomonas aeruginosa , Escherichia coli , and Staphylococcus aureus . To evaluate the anticoagulant activity of the PES‐SF and PES‐SZ membranes, the clotting times using the activated partial thromboplastin time (APTT) and prothrombin time (PT) were measured. The results showed PT level was prolonged for the pure PES membrane with 13 s and for PES‐SF 1 membrane with 12.4 s while the PES‐SZ 1 membrane showed no difference from the control (pure plasma). Contrary to the PT factor, APTT level of the PES‐SF membrane showed the longest time with 43 s. The results of APPT and PT seemed somewhat satisfactory for the PES‐SF while the PES‐SZ membrane did not show any difference from the control sample. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136 , 47686.

Preparation and properties of novel sol-gel-derived quaternized poly(n-methyl pyrrole)/Sn(II)SiO3/CNT composites