Journal of Applied Chemical Research
Volume:11 Issue: 4, Autumn 2017

The use of plant extract is generating the interest of researchers toward cost effective, nontoxic, economic viability and eco-friendly green synthesis of nanoparticles. In the present work, zinc oxide (ZnO) nanoparticles were synthesized using black tea extract and zinc nitrate as the zinc source by the sol-gel method. The synthesized ZnO nanoparticles were characterized by powder X-ray diffraction (XRD), UV-visible spectroscopy and Fourier Transform Infrared Spectroscopy (FTIR). The average crystallite size of ZnO nanoparticles was calculated using Scherrer formula. The X-ray powder diffraction (XRD) analysis revealed the formation of wurtzite hexagonal phase ZnO with average particle size of 32 nm.

The selective nitrosation of β-dicarbonyl compounds with sodium nitrite was carried out under1- methyl-3-carboxymethylimidazolium chloride, prepared from N-methylimidazole and chloroacetic acid, as an acidic ionic liquid. The reaction was found to proceed under relatively mild conditions with excellent conversion and selectivity. The ionic liquid was recycled and reused.

A highly efficient and general method for the synthesis of aryloylamido coumarins derivatives by a three-component condensation of 4-hydroxycoumarin or 4-hydroxy-6- methylpyran-1-one, aryl glyoxals and benzamide in the presence of nano silica supported tin (II) chloride as a heterogeneous catalyst is established. In this method, SnCl2/nano SiO2 was used as green and reusable catalyst. Excellent yields, short reaction times, simple workup, and inexpensiveness and commercially availability of the catalyst are the advantages of this method.

A new, facile, cost effective, and eco-friendly protocol is reported for the synthesis of 2, - dihydroquinazoline-4-(1H)-ones exploring tannic acid as a novel, inexpensive, and biodegradable catalyst. A variety of dihydroquinazolins were prepared from aromatic aldehydes and anthranilamide using catalytic amount of tannic acid under solvent free conditions. Operational simplicity, high yield, and high atom-economy are the important features of this protocol.

This project is aimed at preparation of nano filters using recycled foam of food containers enriched by magnetic nanoparticles, for nitrate removal from water. The characterization of this electrospun magnetic nanofiber depicted a high capacity for nitrate adsorption. The Scanning Electron Microscopy (SEM), X-Ray powder Diffraction (XRD), Energy Dispersive Spectrometry (EDAX) and Inductively Coupled Plasma (ICP) had been applied for this survey. In addition, magnetic behavior of nanoparticles was evaluated by magnetization measurements. The functionality of designing filter against affecting parameters along with the relation of these parameters with each other on the removal efficiency of nitrate was evaluated. It is concluded from the results that the height of the nano filter and the amount of magnetic nanoparticles has the most significant effect on the nitrate removal from water among all other factors. Therefore, optimization techniques can assist to achieve highest efficiency.

Dye sensitized solar cells (DSSCs) are considered as one of the most promising alternativerenewable energy sources. In the structure of DSSCs, a photosensitizer composed of transition metal complexes is used to harvest light. In this work a binuclear complex containing two propionitrile pendant arms [ZnLCu(OAC)]PF6 {L = 1, 6- bis (2-cyanoethyl) -2, 5-bis (2 hydroxy 3-formyl-5-methylbenzyl)-2, 5- diazahexane} has been examined as a non-planar metal based photosensitizer in the fabrication of dye sensitized solar cell. The photovoltaic performance of the fabricated cell was evaluated and photovoltaic parameters were determined. The results showed the conversion efficiency of 0.17%, current density of (Jsc) 0.69 mAcm-2, voltage (Voc) 0.38 v and fill factor (FF) of 0.69 under sun (Am1.5) for the cells. Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) were employed to study the electron transfer mechanism in fabricated cells. The results showed that the potential in cathodic current was more positive indicating that the conduction band position of TiO2 had shifted to positive energies confirming less Voc of the fabricated cell.

Considering the importance of determining potential hazards and factors that can cause an unexpected fire and due to the important role of nanotechnology to achieve more effective properties, this paper presents our experiments on preparing nanocomposites based on Poly(ethylene terephthalate)(PET) and montmorillonite (MMT) as organoclay via melt blending with different clay loadings to investigate their combustion behavior. The main objective of this work was employing cone calorimeter as a perfect device to investigate all combustion parameters such as time to ignition (TTI), heat release rate (HRR), mass loss rate(MLR), CO and CO2 release and peak of heat release rate (pHRR). Thermogravimetric analysis (TGA), Cone calorimeter, limiting oxygen index (LOI) were employed to measure thermal stability and flammability of nanocomposite samples. Morphology and rheology of clay /PET nanocomposites also were investigated using X-ray diffraction (XRD) and Transmission electron microscopy (TEM).The relationship between decrease of intrinsic viscosity and thermal behavior of sample also was studied. Results indicate that clay network was formed in nanocomposites samples which strongly affected flammability of burning samples and resulted more residue during combustion which leads to decrease in dripping of PET during melting.

Dibutyl-Disulfide Montmorillonite (DD-MMT) was synthesized successfully and found to be an excellent adsorbent for Hg(II) removal. The fourier transform infrared spectroscopy (FTIR), x-ray diffraction spectrum (XRD) and scanning electron microscopy (SEM) were used to characterize properties of the absorbent. The effects of several parameters such as solution pH, adsorbent dose, contact time and the initial concentration on the Hg(II) adsorption onto the composite were investigated. DD-MMT had a high capacity for Hg(II) removal that removed Hg(II) (10-100 mg/L) more than 95 % with 2 g/L of adsorbent in only 10 min. The adsorption equilibrium data fitted well to Langmuir isotherm. The maximum adsorption capacity of Hg(II) ions was 312.5 mg/g that was bigger than most of previous methods. Adsorption kinetics of Hg (II) on DD-MMT followed the pseudo-second-order kinetic model. In addition, the method has the advantages of environmental friendly, rapidity, simplicity, and low cost for Hg(II) removal.