Journal of Particle Science and Technology
Volume:1 Issue: 2, Spring 2015

An anionic Fe(II) complex, (BMIM)4[Fe(CN)6] (where BMIM is 1-butyl-3-methylimidazolium), was synthesized in ionic liquid [BMIM][PF6] under reflux condition. The complex was characterized by elemental analysis and spectroscopic methods. The magnetite (Fe3O4) nanoparticles were prepared by the hydrothermal and solvothermal (in ionic liquid [BMIM][PF6]) methods from (BMIM)4[Fe(CN)6] as a precursor. The nanoparticles were characterized by X-ray diffraction (XRD), FT-IR, and scanning electron microscopy (SEM). The results show that the preparation of magnetite using the solvothermal method in [BMIM][PF6] has more advantages such as smaller size and high purity.

An experimental and theoretical energy and exergy analysis was conducted for a cylindrical cavity receiver employed in a parabolic dish collector. Based on simultaneous energy and exergy analysis, the receiver average wall temperature and overall heat transfer coefficient were determined. A simplified Nusselt number for Heat Transfer Fluid (HTF) through the receiver as a function of Reynolds and Prandtl numbers was proposed. Based on correlated Nusselt number, the effects of two Nanofluids of alumina nanoparticles in water and ethylene glycol as base fluid on the performance of system were investigated. When Nanofluids are employed as HTF through the receiver, the energy and exergy efficiency are greater compare to pure water. The minimum enhancement in receiver thermal efficiency is 25% and enhancement greater than 60% is attainable. The results indicate that, by increasing only 5% volume in nanoparticle concentration in water, the receiver thermal efficiency is increased greater than 20%. The effect of nanoparticle volume fraction on exergy efficiency for small HTF mass flow rates is greater than larger mass flow rates. By selecting only 5% volume of alumina nanoparticle in water, for small HTF mass flow rates, enhancement in exergy efficiency greater than 10% is attainable.

Radar absorbing materials, i.e. magnetite (Fe3O4) coated carbon fibers (MCCFs) were fabricated by electro-deposition technique. Black-colored single spinel phase Fe3O4 nanoparticles was easily synthesized by hydrothermal method using reduction of a Fe (III) - Triethanolamine complex in an aqueous alkaline solution at 60-80 ◦C. Uniform and compact Fe3O4 films were fabricated on nitric acid treated carbon fibers. A correlation between magnetic and absorption properties of specimens was made. It was found that the deposition time, and the sequences of the coating process have a significant effect on the reflection loss characteristics of the MCCFs. On the other hand, the temperature of the coating process affects strongly the composition of the thin film. MCCFs prepared at 80 ◦C possesses a much higher loss factor than the one prepared at 60 ◦C. The morphology, phases in the coating layer, magnetic properties and absorption behaviors of the MCCFs were examined using FESEM, XRD, permagraph, vector network analyzer (VNA), respectively. The highest reflection loss that is −10 dB at 12.27 GHz was observed in the sample deposited for four minutes. It was also found out that a uniform deposition layer can be observed in the sample deposited in three steps in which each step takes four minimums.

The main objective of the present work was to synthesis polyamide 6 through anionic polymerization of ε-caprolactam in an internal mixer. The reaction time and the rheological properties of samples during the polymerization were studied. The samples were characterized by Thermo Gravimetry Analysis (TGA), Differential Scanning Calorimeter (DSC) and FT-IR spectrometer. The melt flow behavior and viscoelastic properties of the samples were studied by using a Rheometric Mechanical Spectrometer (RMS). The polymerization reaction was found to be very fast such that it completed within 6 minutes as could be detected by following the mixing torque which reached to a steady state after passing a maximum. These results suggest that there is a reaction time above which the viscoelastic behavior of the samples almost remained unchanged, while the viscosity and elasticity of the samples continue to decrease with polymerization reaction time as a result of thermochemical degradation.

In present study, molecular dynamics simulation of Cadmium (II), Lead (II) and Copper (II) removal from aqueous electrolyte solutions using the ion-exchange process with the zeolite particles was done. The results showed that, most of the particles had the highest affinity of ion exchanging with Lead (II) and the lowest affinity with Copper (II). The calculated mean ion-exchange ratios showed that, except for the zeolites which their pore sizes are in the same range of heavy-metal ions’ size, an inverse relationship exists between this ratios and pore size of the zeolites. Furthermore, the ion-exchanging of zeolites LTJ, ANA, SVR, BEC and MER with aqueous electrolyte mixtures containing equal amounts of Cadmium (II), Lead (II) and Copper (II) were simulated. The results demonstrated that in the competitive exchange of electrolyte mixtures, the maximum mean ion-exchange ratio belongs to the ion which has the highest ratio in the single-ion system. Moreover, ion-exchanging of zeolites LTJ, ANA, SVR, BEC and MER with an aqueous electrolyte solution containing Copper (II), in the temperature range of 300-345 K were simulated. The results showed that, no significant change in the mean ion-exchange ratios were found as a result of temperature variations.

In this study, two new Ni/La-Al2O3 catalysts were prepared by a sol-gel method, with different aluminium precursors (aluminium triisopropoxide and aluminium nitrate). The catalysts were characterized by scanning electron microscope (SEM), X-ray fluorescence (XRF), X-ray diffraction (XRD), BET specific surface area, and particle size analysis (PSA) techniques. The BET results showed that the particles obtained from the aluminium nitrate precursor had a larger surface area (203 m2/g). The PSA data showed particle size distributions between 435 and 754 nm for the catalyst prepared from aluminium triisopropoxide. Finally, the catalysts were evaluated for the dechlorination of monochlorobenzene (MCB).

This paper focused on a simple approach for synthesis of molybdenum oxide (MoO3) nanoparticles and reports a facile route for synthesis of such nanoparticles, using microwave irradiation as a homogenous and powerful source of heating, using ethylene glycol as the solvent and heating medium. For more investigations, besides microwave heating, the obtained solutions were also treated by conventional heating. Finally, product particles were characterized and compared using scanning electron microscopy (SEM) and energy dispersive x-ray microanalysis (EDX). According to the results, microwave irradiated particles showed a good dispersion and stability in relation to the other sample. So, the obtained product was subjected to X-ray diffraction (XRD) analysis to survey the formation of MoO3 nanoparticles. The transmission electron microscope (TEM) micrographs were also recorded to study the size and morphology of the nanoparticles. According to the results, nanoparticles were spherical with an average size of about 50 nm. The absorbance spectrum of MoO3 nanoparticles was further studied using the UV-spectroscopy and the absorbance peak was observed at 257nm.