Iranica Journal of Energy & Environment
Volume:4 Issue: 1, Winter 2013

An efficient green and benign synthesis was developed in the one-pot three component Strecker reaction using heterogeneous nanoporous acid catalyst of SBA-Pr-SO3H with a pore size of 6 nm under solvent free condition. This method has the advantages of short reaction time, ease of the products isolation, excellent yields for the products.

This paper present the study of aqueous CO foam prepared 2 by a mixtures hydrophilic silica nanoparticles and non-ionic Triton X100, TX100, surfactant. The synergistic effects of the mixture on stabilizing the CO2 foam were inferred into few key parameters namely; particles and surfactant concentration, adsorption of surfactant onto the particles via surface tension and adsorption isotherm, foam lifetime and, the size of the bubbles produced. It was found that the adsorption behaviour of TX100 on silica surface exhibit a particular characteristics depend on the concentration of silica, high total surface area available leads to high adsorption of surfactant molecules. The synergetic performance of silica/TX100 in stabilizing foam can be observed at low (0.01%) and intermediate (0.1%) concentration of TX100. Lower concentration required low silica concentration while the intermediate concentration required high silica fraction in the dispersion to stabilize the foam.

In this work, The adsorption of methane onto multi-walled carbon nanotubes (MWCNTs) was studied, in which the influences of temperatureand pressure were investigated. The physical properties of the MWCNT were systematically characterised by Scanning Electron Microscopy (SEM) and Brunauere-Emmette- Teller (BET) surface area measurements. The equilibrium adsorption data were analyzed using threecommon adsorption models: Langmuir, Freundlich and Sips. All of the models fit the experimental results well. The adsorption thermodynamic was carried out at 283.15, 298.15and 313.15 K. The isosteric heat of adosrption (H) was calculated for CH4 and H2, using Claussius–Clapeyron equation. The small amounts of that indicated physical nature of adsorption mechanism.All values were negative, indicating that the adsorptionis feasible and exothermic process in nature.

Direct oxidation of benzene to phenol in liquid phase in the medium of methanol, acetone, acetic acid and acetonitrile as a solvent over chromium catalyst supported on highly ordered nanoporous silica (Cr-LUS-1) by H2O2 were examined. The best results obtained from methanol solvent with 20% yield and selectivity of 90%. Cr-LUS-1 characterized by XRD, nitrogen adsorption-desorption isotherms and visible spectrophotometer.

In the presence of imprinting molecules of Nalidixic acid, uniformly sized molecularly imprinted polymers (MIPs) in nanometer range were synthesized. The MIPs were successfully prepared by precipitation polymerization using methacrylic acid (MAA) and methyl methacrylate (MMA) as functional monomers at different mole ratios. The effect of combination of MAA-to-MMA on the morphology, binding, recognition and release behaviors of the final particles were studied. The produced polymers were characterized by differential scanning calorimetry and their morphology was precisely examined by scanning electron microscopy. We obtained very uniform imprinted nanospheres with diameter of 120- 180 nm. Among the MIP nanospheres the MIPs using combination of MAA and MMA showed nanospheres with lowest mean diameter (120 nm) and the highest selectivity factor (9.7). The adsorption properties of Nalidixic acid in acetonitrile for imprinted nanospheres were evaluated by equilibrium rebinding experiments. Results from binding experiments proved that MIPs exhibit specific affinity to Nalidixic acid in contrast to control polymers and this performance was affected by pH of loading solution and. Moreover, release experiments showed the controlled release of Nalidixic acid in longtime period. The loaded Nalidixic acid was released from the imprinted nanospheres within the 140 h.

A physical vapor condensation process for synthesizing nanosized sulfur powder as a precursor for various industries was simulated by the use of computational? uid dynamic (CFD) modeling. The phase change, swirl flow and heat transfer taking place inside the cyclone are analyzed along with particle formation via gas condensation method. The population balance model is a mathematical framework for the modeling of crystal size distribution (CSD) and the study of gas-phase changes leading to nucleation of the first solid particles. In this paper the Direct Quadrature Method of Moments is used for solving the transport equations of the moments of the size distribution. The temperature, velocity and particle size distribution ranges inside the cyclone were computed. The results show the formation of nanosulfur particles in 1-7 nm range.

Some techniques have been developed to produce carbon nanotubes (CNTs) in sizeable quantities, including arc discharge, laser ablation and chemical vapor deposition (CVD). Arc discharge in liquid environment is a new, simple and cheap method of synthesizing CNTs. CNTs in this study were fabricated by arc discharge in liquid. The present work was undertaken to study the effect of electrical conductivity of liquid on CNTs production and was fabricated using arc discharge between two graphite electrodes submerged in different aqueous solutions of NaCl, KCl and LiCl. For comparative study, CNTs were synthesized under different electrical conductivity conditions and the results were analyzed, compared and discussed.The scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Raman spectroscopy were employed to study the morphology of these carbon nanostructures. Based on LiCl 0.25 N, high-crystalline and a longed multi MWCNTs, SWCNTs were synthesized by using this technique.

Ni-doped SnO2 nanocrystalline powders have been synthesized by the co-precipitation method from SnCl2.2H2O and NiCl2.6H2O. Nanoparticles crystallize in lower temperature (350°C) and shorter time (2hours) respect to other methods. The samples have been characterized by various advanced techniques such as, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Transmission electron microscopy (TEM) and Vibrating sample magnetometer (VSM). The X-ray diffraction reveals that all samples are pure rutile-type tetragonal phase and the average particles size was observed to vary from 32 nm to 24 nm as the nickel content was increased, The TEM images confirms the size of tin oxide particles in nanoscale and VSM measurements indicate that Ni-doped samples have superparamagnetic properties and they are single domain nanoparticles.

Thermally-reduced graphene was obtained from reduction of graphene oxide (GO) via heat treatment under the hydrogen in the range of 300-1100°C. In order to find optimum tempreture, the synthesized graphene has been investigated by X-ray diffraction (XRD), FTIR spectroscopy as well as Raman spectroscopy. The result indicated that the reduced graphene at 900°C (GR900) had the highest quality in comparison with the other temperatures. Additionally, GR900 exhibited a sharp (002) peak corresponding to an interlayer distance of 3.39° A, which is close to that of conventional graphene (3.4°A). However, the structure of GR900 was also investigated by transmission electron microscopy (TEM), scanning electron microscopy (SEM) and the results supported the previous findings.

In this paper a pilot-scale membrane bioreactor (MBR) equipped with nano-membranes treating the hospital wastewaters has been studied in order to evaluate the removal of nutrients. The main goal was to examine the feasibility of the NF-MBR used to treat hospital wastewater. Process efficiency was evaluated in terms of COD, NH3 N, NO3_N, NO3_N and PO4-P removal. The pilot plant located at the Babol Clinic Hospital, _ Babol, Mazandaran, Iran. The performance of NF-MBR pilot for biological nutrient removal was evaluated during 62 days of operation. The NF-MBR resulting in respective HRT of 2.9 h. The influent COD, NH3_N and PO4-P averaged at 688, 11.8 and 3 mg/l respectively. The final treated effluent COD, N 3_N and PO4-P for the same period averaged 35, 1.69 and 0.89 mg/l respectively. The operating results of the pilot plant demonstrate that the NFMBR process is both effective and efficient in meeting the water discharge and reuse quality requirements at the hospital. The NF-MBR showed a high COD removal, stable and complete nitrification. The biological nutrient removal efficiencies were high from the start of operation with COD and NH 3 N removal efficiencies of 92 ± 4% and _ 88 ± 2, respectively. During the course of the experiment PO4-P removal efficiencies increased and finally PO4-P removal efficiency of 68% was achieved. Indicating that the NF-MBR effluent can be directly discharged into natural waters and it’s suitable for reuse.

Basically most of cement based mixtures are likely shrinking. Use of fibers is not a new idea in this case. Previously, there were some evidences that horse hair, straw and cotton fibers were used in mud and mortars in ancient times. Then, utilizing these fibers in concrete mixture may increase concrete workability and decrease shrinkage cracks. Due to nano cross-section of hair and its proper tensile strength this project investigates its application to reduce the shrinkage of concrete mixtures. For this purpose, human hair fibers were used in 0.4 and 0.8 and 1.2 weight percent and the length of the fibers in each case varied between 15 and 60 millimeter and the samples were made of dimensions of 40×40×160 millimeters. Results are shown as considerable amount of hair may reduce in the shrinkage in the hair reinforced concrete.

Interaction of light with nanoparticles led to extensive knowledge about electromagnetic processes which is fundamental. One of the light effects on the metal nanowires, is the changing of the light polarization. The aim of this research is to study size effects and the surrounding environment properties of nanowires on the degree of polarization of scattered light. Gold and silver metallic nanoparticles due to wide spread use of properties were selected herein. Simulated polarization of scattered light with a FORTRAN program was obtained. Parameters affecting the intensity and degree of polarization of scattered light radius, refractive index and the wavelength of incident light was made nanowire. This research was based on theory as well as simulation method. Nanowire lengths, nanowire interaction with the surrounding dielectric environment were changed polarization of the surrounding molecular nanowires. It has been concluded that silver and gold had the same polarization pattern.