JOURNAL OF ADVANCED MATERIALS AND TECHNOLOGIES
Year:2016 | Volume:5 | Issue:3|Papers Count:8

Electrophoretic deposition process as a high-speed process of ceramic body shaping has received great attention in recent years. Suspension conductivity and electrical resistance of the EPD cell as two main parameters in the expression of various kinetic models have been influential. Electrical variation in suspension and deposit had more attraction to change these parameters. While electrodes as a part of electrical system could change conductivity and resistivity. Present study is an endeavor to highlight less mentioned parameter, an electrode material, which could change the EPD models. The experiments were carried out based on aluminum, titanium, stainless steel, copper and graphite electrodes and alumina nano powders. The experiments have shown that the anode material (in cathode deposition) could change EPD models' constants and graphite anodes have same deposition weight in experiment and model. While anodizing of aluminum, with presence of electrical current, deviated results to 0.35. Conductivity based models can predict yield of process better than resistivity based models, since less influencing from electrode material and resistivity of cell. So, we developed a new model based on Ferrari et al.'s model.

Two organic dyes based on indoline were prepared as photosensitizer contain phenothiazine as the electron donor group and acrylic acid (Dye 1) and cyanoacrylic acid (Dye 2) as the electron acceptor anchoring. Spectrophotometric measurements of the synthesized dyes in solution and on a ZnO substrate were carried out in order to assess changes in the status of the dyes. The wavelength of maximum absorption of dye 1 and dye 2 in solution are 412 nm and 424 nm and on ZnO films are 429 nm and 438 nm, respectively. Maximum dye adsorption time around 10h could be utilized with minimum aggregation or precipitation of the dye on photo electrode substrate. The effect of Li ions and composition of the iodide/triiodide based electrolyte on the performance of DSSCs were investigated. A high concentration of Li ions in electrolyte was found to be shift the ZnO conduction band edge to more negative potentials that have a direct effect on recombination phenomena. The Maximum conversion efficiency was achieved for dye 2 in the presence of 1mM Li ions around 5.17%.

In this paper with the aim of investigating the radar absorption behavior of doped barium hexaferrite, composites contain this powder with different weight percent in resin epoxy matrix were prepared. X-ray diffraction analysis (XRD), Vibration sample magnetometer (VSM) and Vector network analysis (VNA) were performed in order to evaluate phase, magnetic properties and microwave absorption properties. According to the results, barium hexaferrite with negligibility amount of non-magnetic hematite phase were was formed. VSM results, representing the reduction of saturation magnetization (Ms) and coercive force (Hc) values in all samples, and the lowest value of saturation magnetization (18.14 emu/g) and coercive force (118 Oe) corresponded to the sample that contain tin ion. According to the VNA results, the maximum absorption is achieved when 50 wt.% of powder is used in resin matrix which was related to the sample with the composition of BaZn0.6Zr0.3Sn0.3Fe10.8O19 at the frequency of 11.1 GHz with -16.3 dB.

A new low cost vanadium sensor developed by immobilizing a direct indicator dye to porous and transparent acetylcellulose film. This sensor was fabricated by binding Gallo cyanine to a cellulose acetate film that had previously been subjected to an exhaustive base hydrolysis for 24h and increase the porosity of the membrane. The cellulose membrane were immediately treated with mixture of 1.00 % (W/V) thiorea and 0.70% (W/V) poly (vinyl alcohol) solution for 48 h at 25°C. The cellulose membrane were separately treated with 0.1% (W/V) solution of gallo cyanine at 25°C with magnetic stirring of the solution for 14h. After washing, the films were dried at 45°C for 20 min. Then the membrane have good durability (>6 months), a short response time (<10 sec) and detection limit 0.003 microgram / ml. The method is easy to perform and uses acetylcellulose as a carrier. The reagents for activity the cellulose support are inexpensive, non-toxic and widely available.

Zinc - silver oxide batteries from components such as the negative electrode (zinc plates), the positive electrode (silver plates), separators (cellulose, slufaty, cotton), electrolytes (potassium hydroxide) were maded. Therefore, the performance of this batteries depends to the performance of the mentioned factors. In this study, effects of carbon content on the polarization resistance of silver electrodes in the KOH environment of zinc - silver oxide batteries was investigated. For this purpose, initially three Ag electrodes (positive plate) containing 5, 10 and 15 wt. % carbon powder was prepared. Then, all three silver electrodes were sintered at temperature 500°C for 13 minutes. Potentiodynamic polarization and electrochemical impedance spectroscopy methods were used in the 1.4% KOH solution to evaluate the polarization resistance of Ag electrodes. Scanning electron microscopy was used to examine the microstructure of electrodes and point analysing. Electrochemical tests results showed that with increasing carbon content, polarization resistance of silver electrodes reduced in the KOH. SEM images were showed that with increasing carbon content, the amount and size of pores increased in the electrodes. Also, point analysis results has implies on reduce in the amount of carbon and oxygen, with the increasing of carbon content in electrodes.

In this research, We reported a novel and facile approach to fabricate rGO nanosheet arrays on 3D porous nickel foam. A graphene layer with the sharp edges and wrinkles was obtained on nickel foam by an electrophoretic deposition (EPD).The fabricated electrodes were characterized using scanning electron microscope (FE-SEM).The GO sheets on the nickel foam was annealed at 300̊C, 600oC and 900oC for 4 h under flow of Ar. The electrochemical activities of super capacitors were assessed using cyclic voltammetry (CV) and charge-discharge measurements. A maximum specific capacitance of the Go annealed at 900oC can reach up to 148 Fg-1 at a scan rate of 5mVs-1, which is higher than Go annealed at 600oC (115 Fg-1), Go annealed at 300oC (72 Fg-1) and Go (52 Fg-1). The super capacitor based on a GO with 900oC of annealing temperature showed long cycling stability with 96.1% of capacitance retention after 200 cycles.

The Strain Induced Melt Activation (SIMA) process is one of the semi-solid forming processes in Preparation of non-dendritic microstructures. In this research, verifying the effects of SIMA process on microstructure and the corrosion behavior of Al-Zn-In sacrificial anode was studied. The effect of plastic deformation on the semisolid microstructure of Al-Zn-In alloy was investigated by applying 10-40% uniaxial compression at the ambient temperature and the semi-solid treatment was carried out at the range of 640 to 660 °C for 40 min. Investigate the behavior corrosion by Tafel polarization test was performed in a solution of Sodium Chloride 3.5%. The results indicated that the microstructure of SIMA processed specimens is finer and more Globular than the microstructure of initial material. With increase in the compression ratio from 10 to 30%, The sphericity increased significantly but the variation rate of the average grain size increased and the shape factor decreased with more increase in the compression ratio up to 40%. The average size and sphericity of α-Al solid grains increased with the increase of the temperature heat treatment. Tafel test results showed, Corrosion potential samples alloys Al-Zn-In is more negative and lowest rate of corrosion related to sample heat treated at 640°C with the compression ratio 30%. The results of scanning electron microscopy also indicate the uniform corrosion under aforementioned conditions.

Mica clay minerals group are relatively abundant of minerals in Iran, especially iron Ore. There areusually found as the tailings on the side of hematite. Numerous applications in the area of traditional industries and the high-tech area for it has been found that, depending on the chemical, physical, and thermal properties of it. So complete overview of mica used in this research has been done. Due to the high volume of tailings Sirjan Gol Gohar mines, Identify and determine their applicability for use in other industries is important for two reasons. First, they are widespread and cause environmental problems and second create added value for them. n this research, one of the mine tailings with microscopic techniques, XRF, XRD and STA was fully recognized and examined its engineering properties. According to the review of applications and properties mica are investigated, Potential uses for tailings found.