Journal of Applied Research in Chemistry
Year:2017 | Volume:10 | Issue:4|Papers Count:11

Pyrolytic carbon usually is deposited on a substrate surface as a carbon coating following pyrolysis of some light hydrocarbon gases at high temperatures from about 900 to 2200 °C by the chemical vapor deposition method. This carbon material structurally consists of a large number of graphitic nanocrystals or graphitic sheets of only a few nanometers in size. Due to high biocompatibility, physical, mechanical, wear resistance, and oxidation resistance properties, it has been used in various fields such as some medical implants (prosthetic heart valves and finger joint implants), nuclear industry (coating of nuclear fuels in high temperate gas-cooled reactors), voltammetric electrochemical sensors, aircraft brake disks, high temperature refractory materials (coating of graphite tubes in graphite furnace atomic absorption spectroscopy), and aerospace industries (nozzle of rocket motors or nose shields of some missiles). In this paper, along with a brief introduction of its structure and fabrication methods, a review of its diverse applications is also presented.

In this study, a new method is developed for copper-catalyzed N-arylation of primary amines, and amino alcohols in ethylene glycol medium. The catalytic system is very simple and consists of a Cu (II) chloride salt (0.1 equivalent), potassium carbonate (2.0 equivalent), and ethylene glycol solvent. Meanwhile, ethylene glycol plays a dual role by activating the catalyst and providing a homogenous medium for the catalytic processes. Thus, under the given conditions there is no need to use auxiliary ligands and other organic solvents to activate the catalyst. All reactions take place under microwave irradiation in short time periods (10 to 20 minutes) giving moderate to good yields of the products (60-75%). In addition, amination of aryl halides by aqueous ammonia is also carried out and the corresponding aromatic amines are produced in high yields.

Nowadays, use of polymeric mulch such as the polymer based on acrylamides is developing due to being eco-friendly, safety, and low cost. Polyacrylamide is odorless, colorless, non-polluting the ground water and surface water, soil and plant tissues. In this study, for the first time, copolymer based on acrylamide and acrylic acid was used in small-scale plots in experimental conditions for use in soil for the purpose of its stabilization and preventing its loss.Copolymer based on acrylamide and acrylic acid was synthesized by free radical polymerization.The water-soluble polymer synthesized by free radical polymerization and characterized using Fourier-transform infrared spectroscopy and thermogravimetric analysis. To calculate the negative charge density of samples, titration method was performed. By increasing density of negative charge of polymer chains, the apparent viscosity decreases with higher rate. It can be concluded that in the presence of acrylic acid, the ions shrank and became more like spheres which ultimately results in coil-like configuration. As the copolymerization reaction proceeds from 50% to 90% weight percent of acrylic acid, the rate slows down due to accumulation of negative charges and the molecular weight of copolymers decreases with increasing the anionic degrees of copolymers.Finally, soil loss was determined using 0.4, 0.6, 1, 2, 3, 4 and 6 gr/m2 of copolymers in water and solutions sprayed on the soil surface before implementation of artificial rainfall, also its continuity in 30min rainfall was studied.

There are many solvents and pollutants in food and water such as dioxane that cause genetic mutations and diseases such as cancer. Solid phase microextraction was introduced as a new method for analysis of pollutant. In this study, composite of zinc oxide nanoplatepolyaniline as a new cover for solid phase microextraction was used for extraction of dioxane.The zinc oxide nanoplates were synthesized by hydrothermal method on the fused silica fiber.After that, a thin film of polyaniline was set on the zinc oxide nanoplates by evaporation method.Investigation of SEM images showed that the thickness of nanocomposite was between 21.5 - 37.6 nanometers. Optimization of extraction parameters was performed by experimental design and gas chromatography. The optimum conditions were achieved as follows, the extraction temperature: 90° C, extraction time: 50 min, salt percentage: 15%, and desorption time: 20 min. The calibration curves were linear from 5 to 100 ng ml-1 for analyte and the limit of detection was 0.5 ng ml-1.Single fiber repeatability (n=4) was13%. The spiked relative recoveries at 40, 100 and 150 ng ml-1 for environmental water sample were in the range of 97– 101%.

In recent years, researchers have used biomaterials for synthesis of composites in order to improve tissue engineering and repair of damaged tissues. In this study, synthesis and characterization of gelatin-carbon nanotube-hydroxyapatite nanocomposite with in situ synthesis method were carried out and the effect of biopolymer concentration was evaluated.Nanocomposites were characterized using infrared spectroscopy (FT-IR), energy dispersive of X- ray (EDAX), X- ray diffraction (XRD), and scanning electron microscopy (SEM) methods.Also, in vitro bioactivity took place by immersion in SBF solution. Based on the results, formation and distribution of nano hydroxyapatite particles as a mineral phase in biopolymer matrix was confirmed. Bioactivity study showed that the gelatin was a suitable matrix for nucleation and growth of the hydroxyapatite nanocrystals, and increasing the concentration of gelatin had an optimum effect on morphology and distribution of nanoparticles.

Ionic liquids containing imdazolium cations and chloride anions possess properties categorizing them as green solvents. What gives such ILs these characteristics is that their physical and thermodynamic properties may be tuned on substitution of the halide anion by various organic and inorganic anions. Two anion exchange methods, namely metathesis and acid-base neutralization have been investigated in this work.In metathesis method, 1-alkyl-3-mehylimidazolium chlorides containing butyl, hexyl, and octyl groups have been reacted in aqueous media with sodium and potassium salts, respectively, of BF4- and PF6-anions and the results obtained have been compared with those by reactions with HBF4- and HPF6 acids. The effects of alkyl chain length and anion type on the reaction parameters have also been compared. Comparison of the two methods shows that metathesis is carried out under milder reaction conditions. Therefore, a comparison of chloride anion exchange with OTf-, NTf2- and NO3- was made using the corresponding ammonium, lithium, and silver salts. The most convenient conditions for metathesis were those in the preparation of NO3- and the harshest conditions were required for the synthesis of NTf2- and OTf containing ionic liquids.

A new method for solid-phase extraction and preconcentration of trace Zn2+ ions from aqueous solution using silica coated magnetic Fe3O4 nanoparticles modified with 8-hydroxyquinoline (Fe3O4@SiO2-8-HQ) as adsorbent prior to spectrophotometric determination with dithizone is described. Magnetic sorbent was characterized by SEM and FT-IR techniques. All adsorption experiments were carried out in a batch system. The magnetic adsorbent bearing the Zn2+ was easily separated from the aqueous solution by applying an external magnetic field and the adsorbed Zn2+ was desorbed using an acidic solution. Various factors which influenced the recovery of the analyte including solution pH, contact time, adsorbent dosage, sample volume, concentration and volume of desorbing solution, and foreign ions were investigated. The experimental adsorption data were well fitted to the Langmuir isotherm model. Kinetic studies showed that the adsorption followed pseudo-second-order model. Under the optimal, the enrichment factor, detection limit and relative standard deviation for determination of Zn2+ (50 mg l –1) were found to be 84, 2.7 mg l –1, and 2.93%, respectively. The proposed method was successfully applied to the determination of zinc in real water and wastewater samples.

In this work, the copolymers which are based on the methacrylate and have methyl imidazolium ionic liquids, were prepared from the reaction between chloroethyl methacrylate, and methyl imidazolium monomer ionic liquids. Then radical copolymerization of this monomer with the methacrylic acid in the presence and absence of cross-linking agent, bisacrylamide, were carried out. The percentage of cross-linking agent was 3, and 5 percent, respectively. Ratio of monomers in copolymers was 1: 1 and 1: 3. Then loading and releasing of acarbos for these copolymers as drug delivery system were investigated. Then nano particles of copolymers containing the drug under the process of freeze drying processes were synthesized.Then drug release of acarbose at pH=7 and pH=1 has been investigated, which are similar to the pH of the stomach and intestines. The percentage of drug release in the intestine showed higher than the stomach, which could be important in drug delivery. The thermal behavior of copolymers in the presence and absence of a crosslinking agent has been also studied.

The utility of quinoline derivatives in the areas of medicine, food, catalyst, dye, refineries, and electronics is well established. As a result, the synthesis of quinolines have been an attractive goal for an organic chemist. In this work, amino and cyano quinolines derevatives have been synthesized in an efficient method by treatment of o-aminoaryl ketones and b-cyano carbonyl compounds using FeCl3•6H2O as an available and inexpensive catalyst via Friedlander reaction.By this approach, the related Quinolines have been prepared in excellent yields and purity and well characterized. In addition, the basic contribution of the catalyst to the efficiencies and the products has been determined and discussed. Finally, the antibacterial tests on these compounds indicate considerable effects on the antibacterial properties against Staphylooccocus positive gram and Escherichia Coli bacteria.

Nowadays progress in industrial activities leads to the generation of large amounts of pollutants. Among these pollutants are dyes and pigments which emitted from textile industries into wastewaters. Concerning the toxicity of these pollutants, it is necessary to remove them from water resources. In this research the capability of graphene oxide for adsorption removal of two anionic reactive dyes, Reactive Red 195 (RR195), and Reactive Blue 19 (RB19) as model compounds was assayed. Important parameters influencing the adsorption of RR195 and RB19 including pH, adsorbent dose, and contact time were optimized. Furthermore, the adsorption kinetics studies and adsorption isotherms were investigated. The obtained results showed that the adsorption process of both dyes best fitted in pseudo-second-order model and adsorption process of RR195 was adopted with the Temkin model while adsorption process of RB19 best fitted in Langmuir isotherm model.