Volume 233, Issue 7

A novel aggregation induced emission (AIE) active anthracene based dihydroquinazolinone derivative (probe 1 ) has been synthesized and characterized by means of spectroscopic methods. The photophysical properties of this probe have been investigated in solvents of different polarity display that fluorescence states are of intramolecular charge transfer (ICT) character. Probe 1 show clear AIE behavior in water/THF mixture on reaching water fraction 95%. The AIE behavior of probe 1 have been exploited for the detection of metal ions in aqueous solution which reveals high selectivity and sensitivity towards Cu 2+ ions by colorimetrically and function as a chemosensor in a remarkable turn-off fluorescence manner. Further, the experimental results were investigated by computational means by optimizing the ground state geometries of probe 1 and probe 1 -Cu complex using density functional theory (DFT) at B3LYP/6-31G ∗∗ and B3LYP/6-31G ∗∗ (LANL2DZ) levels of theory. Intra-molecular charge transfer was observed in probe 1 while ligand to metal charge transfer (LMCT) for probe 1 -Cu complex.

Conducting cadmium oxide (CdO) thin film samples were deposited on amorphous glass substrates at the optimized substrate temperature (200 °C) as a function of carrier gas pressure (10.8, 12.7, 14.7, 16.7 and 18.6 × 10 4 N m −2 respectively) by spray pyrolysis technique using nebulizer. XRD results showed that all the CdO thin films were polycrystalline in nature along with cubic structure. The scanning electron microscopy (SEM) images revealed that all the thin films had a sphere like grains without any cracks. The elemental composition of the film is analyzed with EDAX spectrum formed in stochiometric range. Direct energy gap values were found to be had decreased from 2.46 to 2.42 eV as the function of carrier gas pressure had increased from 10.8 to 14.7 × 10 4 (N m −2 ) and the energy gap increased further. All the as deposited samples of Cd–O vibration bond (690 cm −1 ) were confirmed by FTIR spectrum. PL emission spectra revealed that all the CdO thin films exhibit a strong emission (green) peak at 520 nm. High carrier concentration (2.88 × 10 19 cm −3 ), low resistivity (4.76 × 10 −3 Ω cm) and high figure of merit (25.0 × 10 −3 ) were observed for 14.7 × 10 4 (N m −2 ) carrier gas pressure of CdO thin film.

Nonsteroidal anti-inflammatory hydrophobic drugs (NSAIDs) are amongst the most commonly given categories of drugs worldwide in the treatment of pain, irritation and some of them even fever in many conditions. Critical micelle concentration of NSAIDs with Naproxen sodium (NS) and its mixture with non-ionic surfactants i.e. Tween 20, Tween 40 and Tween 60 was investigated at 293 K, 303 K, 313 K and 323 K at different concentrations using surface tension and dynamic laser light scattering (DLS) techniques. Due to amphiphilic behaviour in aqueous solution NS form aggregates at sufficiently high concentration. Thermodynamic/adsorption properties like free energy of micellization (ΔG mic ), enthalpy of micellization (ΔH mic ), entropy of micellization (ΔS mic ), Γ mic and area per molecule (A 2 ) of NS in the presence of surfactants were also measured at different temperatures. The results showed that the presence of surfactants favoured the ΔG mic and become more enhanced with increase in temperature. Further the solubility of drug is more favourable with increase in polyethylene chain in basic surfactant molecules i.e. 20–60, which indicates that Tween-60 enhanced the solubility of NS more comparatively to Tween-40 and Tween-20 and may be applied as best additive for solubilisation of NS.

The main purpose of the present study is to determine anticorrosion properties in oilfield produced water of the N′ -phenylbenzohydrazide and its metal complex derivatives by experimental studies and quantum chemical calculations as well as investigate the relationship between experimental and theoretical study results through a correlation study. The molecular structures of N′ -phenylbenzohydrazide and its metal complexes (Cu, Mn, Co) obtained characterized by using UV–Vis and FT–IR techniques. The electrochemical polarization measurements, electrochemical impedance spectroscopy (EIS) and scanning electron microscopy techniques were used experimentally in the discovery of corrosion inhibition properties of the metal complexes in oilfield produced water. Some important quantum chemical parameters of the metal complexes were calculated using quantum chemical software, Gaussian 03 W. The electrochemical polarization measurements showed that the inhibition efficiencies of metal complexes were increased with an increase of concentration. The results showed that the metal complexes acted as anodic-type inhibitors. The experimental inhibition activities of studied metal complexes were found to be highly correlated with calculated some parameters, E T , E LUMO , E HOMO and E Gap .

The interaction between pentoxifylline (PTX) and bovine serum albumin (BSA) was studied under physiological condition by spectroscopic, voltammetry and molecular modelling techniques. The results of fluorescence studies revealed that the quenching mechanism of BSA by PTX was a static procedure. Binding constant of PTX-BSA was calculated and its value found to be 8.895 × 10 4 M −1 , which is in close agreement with the results obtained from UV-Visible and voltammetry approach. The negative values of thermodynamic parameters (ΔG, ΔH and ΔS) indicated that van der Waals force and hydrogen bonding play major roles in the interaction of PTX with BSA. Based on Forster’s theory of non-radiation energy transfer, the binding distance (r) between the donor (BSA) and acceptor (PTX) was found to be 5.38 nm (298 K). The results of UV-Visible and circular dichroism (CD) spectroscopy showed that PTX interacts with BSA and induces conformational changes by reducing the α -helix content. The results of the UV-visible and voltammetry studies were further verified by the molecular docking method. Molecular modelling studies revealed possible residues involved in the drug-protein interaction and indicated that PTX binds to Site IIA of BSA.

Zinc oxide (ZnO) nanorods were fabricated through hydrothermal route and employed for the adsorption of Cr(VI) ions from aqueous medium. Zinc nitrate hexahydrate (Zn(NO 3 ) 2 .6H 2 O) was used as a zinc precursor and Triton-x 100 was used as a capping agent. As synthesized ZnO nanorods were characterized by UV-visible spectroscopy (UV), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and energy dispersive X-Ray spectroscopy (EDX) techniques. The adsorption affecting parameters were investigated for maximum adsorption of Cr(VI) onto ZnO nanorods. The adsorption kinetics, isotherms, and thermodynamics were applied for adsorption mechanism evaluation. Maximum adsorption of Cr(VI) ions (250 mg/g) was achieved using 0.055 g/L ZnO dose at pH 2.0 for the contact time of 30 min. Pseudo-second-order kinetic model and Langmuir isotherm explained well the Cr(VI) adsorption onto ZnO nanorods. The Cr(VI) adsorption onto ZnO was spontaneous and endothermic in nature. In view of promising adsorption efficiency, ZnO nanorods could possibly be used for Cr(VI) ions removal from wastewater and also extendable for the adsorption of other heavy metals ions.

The adsorption of methylene blue was carried out by adsorbent prepared from Acacia modesta . The sample wood was collected from Dir lower Khyber Pakhtunkhwa Pakistan. Chemical activation of the sample was conducted for surface efficiency. Surface of raw and activated sample was elucidated by scanning electron microscope (SEM), energy dispersive spectroscopy (EDS) and Fourier transform infrared (FTIR) techniques. Adsorption of methylene blue was studied on raw and activated samples by kinetics adsorption at different adsorption temperatures such as 20 °C, 30 °C and 40 °C. The adsorption equilibrium was established within 2 h. Elovich, Bhangam, and Parabolic diffusion equations were applied to the adsorption kinetics data and were found fit for adsorption. From adsorption kinetic data the parameters like ΔH ≠ , ΔS ≠ and ΔE ≠ were calculated and showed that the adsorption process was spontaneous process. Entropy in descending order shows that dye molecules adsorbed in an oriented position.

Fe-containing carbon nitrides (Fe–CN) prepared with various CN precursors, including dicyandiamide, melamine, guanidine hydrochloride and urea, were characterized by X-ray diffraction, thermal gravimetric analysis, N 2 physisorption, transmission electron microscopy, X-ray photoelectron spectroscopy and atomic emission spectrometer measurements, and used as catalysts to catalyze the rhodamine B oxidation with H 2 O 2 as oxidant. Characteristic results showed that Fe–CN exhibits different compositions, properties and catalytic performances if different CN precursors are used. The Fe–CN prepared from dicyandiamide contains mainly CN phase and certain amounts of surface Fe 2 O 3 phase, exhibits the best activity; while that prepared from urea contains mainly Fe 2 O 3 phase and few amounts of CN phase, exhibits the worst activity. Contrasting experiments conducted under light irradiation, with a supported Fe/CN_D catalyst, and that using a washed catalyst, suggested that the surface Fe 2 O 3 is the active site of the reaction.

The plants assisted green synthesis of nanoparticles have drawn a momentous importance worldwide. NiO is one the metal oxides researched comprehensively for decades and still has dominance in the field of photo-catalysis. In present study NiO and Ag–NiO were successfully prepared by a simple and environmentally friendly method using nickel nitrate, silver nitrate and leaves extract of Azadirachta indica L. plant as precursor materials. The prepared materials were characterized by XRD, SEM and TGA. Then the photo-catalytic efficiency of NiO and Ag–NiO were evaluated by aqueous phase photo-degradation of rhodamine B as a model pollutant under ultraviolet irradiations. About 40% and 96% of 200 mg/L (50 mL) degraded in 120 min at 40 °C over NiO and Ag–NiO as photo-catalyst respectively. The apparent rate constants were determined as 0.0109, 0.0165, 0.0175 and 0.0190 per min at 30, 40, 50 and 60 °C respectively. 14.6 kJ/mol was calculated as activation energy of reaction.