Publications

Photochromic properties of (E)‐3‐(2‐adamantylidene)‐2‐[5‐(4‐diethylaminophenyl)‐2‐methyl‐3‐furylethylidene] succinic anhydride doped in polystyrene film

Purpose The purpose of this paper is to evaluate the photochromic performance of photochromic compounds in polymer matrices. Design/methodology/approach The polystyrene films doped with photochromic fulgide were prepared and the effect of UV irradiation were studied using spectrophotometer. The reversible reaction was effected using white light. The effect of heat was also determined. Findings A film of the green coloured fulgide 2‐E doped in polystyrene polymer was irradiated with UV light (366 nm), the film turned blue. The latter colour was partially switched back to the original green colour when the film was irradiated with a white light. Increasing the annealing temperatures, increases the percentage conversion of 2‐C to 2‐E . The observed large bathochromic shifts in λ max of 2‐C and the partial conversion of 2‐C to 2‐E were rationalised on the bases of electronic and steric effects. It was found that both isomers 2‐C and 2‐E absorbed white light and they interconvert. The kinetics of photocoloration and photobleaching processes were followed spectrophotometrically by monitoring the absorbance of the ring closed product 2‐C at its λ max of 620 nm. The apparent first‐order rate constants for both processes were determined. It was found that there was slight variation in the rate constant for photocoloration reaction with annealing temperature. On the other hand, the apparent first‐order rate constant of the photobleaching reaction decreases with increasing the annealing temperature. Research limitations/implications The polystyrene polymer doped photochromic fulgides described in the present paper was prepared and studied. The principle of study established can be applied to any type of polymer or to any type of photochromic compounds. Practical implications The photochromic materials developed can be used for different applications, such as coatings and holography. Originality/value The method developed may be used to enhance the performance of photochromic materials.

4-(4-Bromophenyl)-2-oxo-1,2,5,6-tetrahydrobenzo[<i>h</i>]quinoline-3-carbonitrile

In the mol­ecule of the title compound, C20H13BrN2O, the tetra­hydro­benzo[h]quinoline fused-ring system is buckled owing to the ethyl­ene –CH2CH2– fragment, the benzene ring and the pyridine ring being twisted by 17.7 (1)°. The 4-substituted aromatic ring is bent away from the pyridine ring by 82.3 (1)° in order to avoid crowding the cyanide substituent. Two mol­ecules are linked by a pair of N—H⋯O hydrogen bonds to form a centrosymmetric dimer.

A new way of synthesis nanohybrid cation‐exchanger applicable for membrane electrode

A novel polymeric composite namely, PANI‐PW/Ag (silver doped polyaniline phosphotungstate) was expediently obtained by sol‐gel method. PANI‐PW/Ag was characterized by Fourier transform infrared spectroscopy, X‐ray powder diffraction, UV–vis spectrophotometry, scanning electron microscopy, and thermogravimertic analysis. On the basis of ion exchange capacity and distribution studies, PANI‐PW/Ag, highly selective and sensitive to Cu(II), was used for the preparation of ion selective membrane for Cu(II). The electrode exhibits good potentiometric response for Cu(II) over a wide concentration range (1.0 × 10 −1 −5.0 × 10 −6 mol) with Nernstian slope of 27.8 mV per decade. Response time of the electrode is 9 s and it could be used for a period of 3 month and exhibits good selectivity toward Cu 2+ in comparison to alkali, alkaline earth, transition, and heavy metal ions, with no interference caused by other heavy metals. POLYM. COMPOS., 35:1436–1443, 2014. © 2013 Society of Plastics Engineers

Selective Adsorption of Iron(III) Ions Based on Nickel(II) Oxide-copper(II)Oxide Nanoparticles

Background: Water contamination and its remediation are currently considered a major concern worldwide. Design of effective methods for water purification is highly demanded for the adsorption and removal of such pollutants. Objective: This study depicts the effectiveness of nickel oxide-copper oxide nanoparticles (NiO-CuO), which can extract and remediate ferric ions, Fe(III), from aqueous solutions. Methods: The NiO-CuO nanoparticles were simply prepared by the co-precipitation method and then used as adsorbent with respectable advantages of high uptake capacity and surface area. Results: Adsorption of Fe(III) onto NiO-CuO nanoparticles showed an uptake capacity of 85.86 mgg-1 at pH 5.0. The obtained data from the carried-out experiment of Fe(III) adsorption onto NiO-CuO nanoparticles were well suited to the Langmuir isotherm and pseudo-second-order kinetic models. Moreover, different coexisting ions did not influence the adsorption of Fe(III) onto NiO-CuO nanoparticles. The recommended methodology was implemented on the adsorption and removal of several environmental water samples with high efficiency. Conclusion: The designed method displayed that NiO-CuO nanoparticles can be used as a promising material for the adsorptive removal of heavy metals from water.

Biosynthesis, structural characterization and antimicrobial activity of gold and silver nanoparticles

Iron-group electrocatalysts for ambient nitrogen reduction reaction in aqueous media

Electrochemical nitrogen reduction reaction (NRR) is considered as an alternative to the industrial Haber-Bosch process for NH3 production due to both low energy consumption and environment friendliness. However, the major problem of electrochemical NRR is the unsatisfied efficiency and selectivity of electrocatalyst. As one group of the cheapest and most abundant transition metals, iron-group (Fe, Co, Ni and Cu) electrocatalysts show promising potential on cost and performance advantages as ideal substitute for traditional noble-metal catalysts. In this minireview, we summarize recent advances of iron-group-based materials (including their oxides, hydroxides, nitrides, sulfides and phosphides, etc.) as non-noble metal electrocatalysts towards ambient N2-to-NH3 conversion in aqueous media. Strategies to boost NRR performances and perspectives for future developments are discussed to provide guidance for the field of NRR studies.

Nanocomposites for hydrolysis of NaBH4, nanomaterials for hydrogen storage applications

Behavior of some natural fiber composites

Boosting the performance of visible light‐driven WO ₃ /g‐C ₃ N ₄ anchored with BiVO ₄ nanoparticles for photocatalytic hydrogen evolution

In this article, a ternary WO3/g-C3N4@ BiVO4 composites were prepared using eco-friendly hydrothermal method to produce efficient hydrogen energy through water in the presence of sacrificial agents. The prepared samples were characterized by scanning electron microscopy (SEM), scanning transmission electron microscopy (STEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), ultraviolet-visible (UV-vis), Brunauer-Emmett-Teller (BET) surface area, and photoluminescence spectroscopy (PL) emission spectroscopy. The experimental study envisages the formation of 2-D nanostructures and observed that such kinds of nanostructures could provide more active sites for photocatalytic reduction of water and their inherent reactive-species mechanism. The results showed the excellent photocatalytic performance (432 μmol h−1 g−1) for 1.5% BiVO4 nanoparticles in WO3/g-C3N4 composite when compared with pure WO3 and BiVO4. The optical properties and photocatalytic activity measurement confirmed that BiVO4 nanoparticles in WO3/g-C3N4 photocatalyst inhibited the recombination of photogenerated electron and holes and enhanced the reduction reactions for H2 production. The enhanced photocatalytic efficiency of the composite nanostructures may be attributed to wide absorption region of visible light, large surface area, and efficient separation of electrons/holes pairs owing to synergistic effects between BiVO4 and WO3/g-C3N4. The prepared samples would be a precise optimal photocatalyst to increase their suppliers for worldwide applications especially in energy harvesting.

Detection of aprepitant drug based on low-dimensional un-doped iron oxide nanoparticles prepared by a solution method

Electrical conductivity and ion-exchange kinetic studies of polythiophene Sn(VI)phosphate nano composite cation-exchanger

A polymeric hybrid nanocomposite, namely polythiophene tin(IV)phosphate (PTh–SnP), was expediently synthesized by incorporating polythiophene (PTh) in tin phosphate (SnP) to enhance the conducting behavior and sorption of heavy metal ions by porous polymeric cation exchanger. Composite was characterized by Fourier Transform-Infra Red and Transmission Electron Microscopy. The dc electrical conductivity studies carried out on the composite, showed conductivity within the range of 4.0 × 10−2–1.0 × 10−3 S/cm−1; measured by a 4-in line-probe dc electrical conductivity measuring technique. Ion-exchange kinetics for few divalent metal ions was evaluated by particle diffusion-controlled ion-exchange phenomenon at four different temperatures. The particle diffusion mechanism is confirmed by the linear τ (dimensionless time parameter) vs t (time) plots. The exchange processes thus controlled by the diffusion within the exchanger particle for the systems studies herein. Some physical parameters like self-diffusion coefficient (D0), energy of activation (Ea) and entropy (ΔS°) have been evaluated under conditions favoring a particle diffusion-controlled mechanism.

From industrial jute fibre spinning wastes to biofibre-reinforced plastics

A huge amount of jute caddies is generated as a by-product in jute spinning industries solid waste is generally disposed of either in landfilling or burned as boiler fuel triggers environmental pollution. Owing to their higher fibre length and moderate single fibre tensile properties, the waste fibres in jute caddies can be transformed into dry fibre preform which in turn could be used in the production of composites. In this work, jute caddies were cleaned by compressed air before being pressed into dry fibre preform in order to increase the fibre packing capacity in the composites. Thermoplastic composites were manufactured by combining 40 % fibre with 60 % polypropylene (PP) matrix (by weight) using a hot press machine. The effect of chemical treatments (alkali and benzoyl chloride) on jute fibre was characterized by FTIR, TGA, and SEM. Tensile and flexural properties were evaluated to see the performance of composites. The findings of this study demonstrated that this newly developed dry short fibre jute caddies-based thermoplastic composites possess improved flexural properties by ⁓42.75 % if they are chemically modified with binders. Polyvinyl alcohol (PVA) can react with the functional groups of jute fibre to form strong hydrogen bonding that may result in enhanced bending properties of the composites. Therefore, the proposed composite made from jute caddies waste could be ideally used in semi-structural composite applications leading to a sustainable approach to disposing of jute industry solid waste through a circular economy.

Visible light functioning photocatalyst based on Al2O3 doped Mn3O4 nanomaterial for the degradation of organic toxin

Al2O3 doped Mn3O4 nanomaterial was synthesized by low-temperature stirring method and applied as a catalyst for the degradation of organic pollutants under solar light for prospective environmental applications. The morphological and physiochemical structure of the synthesized solar photocatalyst was investigated by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy-dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS). FESEM showed a mixture of nanowires and aggregated nanoparticles. This Al2O3 doped Mn3O4 nanomaterial exhibited high solar photocatalytic degradation in a short time when applied to brilliant cresyl blue (BCB). Thus, the synthesized nanoparticles can be used as an efficient solar photocatalyst for the degradation of BCB.

CCDC 976282: 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.

2-(1,3-Benzothiazol-2-yliminomethyl)-2-naphthol

In the title mol-ecule, C(18)H(12)N(2)OS, the dihedral angle between the two fused-ring systems is 7.2 (1)°. The hydr-oxy group forms an intra-molecular hydrogen bond with the imino group.

Self-supported spinel FeCo₂O₄nanowire array: an efficient non-noble-metal catalyst for the hydrolysis of NaBH₄toward on-demand hydrogen generation

NaBH₄ has been considered as one of the most advantageous candidates for chemical hydrogen storage, but it is still a huge challenge to design efficient non-noble-metal catalysts for on-demand hydrogen generation from NaBH₄ hydrolysis. In this paper, we demonstrate for the first time that a spinel FeCo₂O₄ nanowire array supported on carbon cloth (FeCo₂O₄ NA/CC) behaves as an efficient earth-abundant catalyst toward NaBH₄ hydrolysis in alkaline solutions with an activation energy of 44.98 kJ mol^-1. Such FeCo₂O₄ NA/CC offers a hydrogen generation rate of 2551 ml min^-1 g^-1 under ambient conditions, with good stability and reusability. Its use as an ON/OFF switch for on-demand hydrogen generation is also demonstrated successfully.

Electro-catalyst based on cerium doped cobalt oxide for oxygen evolution reaction in electrochemical water splitting

The impact of position and number of methoxy group(s) to tune the nonlinear optical properties of chalcone derivatives: a dual substitution strategy