Papers by Keyword: Electrolyte

Abstract: Natural rubber has an important role in many applications such as tyre products due to excellent elasticity and high friction causing wear on the tire and leading to energy dissipation in the form of heat and noise. Although reinforcing both inorganic and organic fillers can be a solution, it generally needs expensive coupling agent. Finding an excellent coupling agent by considering to environmentally friendly materials and economic aspect, is an interesting study. This study reported modification of natural rubber through copolymer grafting of starch onto natural rubber latex using Glow Discharge Electrolysis Plasma (GDEP) with varying of electrolyte. The experimental indicated that the electrolytes generally give significant effect to percent yield of the hybrid natural rubber-starch product. The highest percent yield is obtained from adding KCl. Addition of the divalent salts such as MgCl₂ and CaCl₂ disturbs the process due to reaction the salts with stabilizing system in natural rubber latex. Addition of NaOH is able to enhance the reaction performance with considering the radical elements recombination. The starch part as polar part and the natural rubber as non polar part building up the hybrid natural rubber-starch products, correlate with hydrophilicity and degradation of the both parts. This study results in the lowest contact angle of 54.8⁰, the highest percent yield of 8.6 %,, and the highest starch content in the product of 1.6%.

Abstract: PVDF-HFP nanofibers are reinforced by (0, 10, 16 and 30wt% ) of butadiene rubber (BR) and are crosslinked by the UV curing during the electrospinning process. These electrospun clothes are soaked with 70wt% uptake of EMI-Tf ionic liquid for solid state electrolytes applications. These electrolytes are investigated by a broadband dielectric spectroscopy over a wide temperature range from-40 to 80 OC. It is found that the temperature dependence of conductivity of all the samples not only follow the VFT relation but also follow the Debye-Stokes-Einstein relation implying the coupling between the ionic conduction and the segmental motion of the polymer matrix. Also, the results indicated that the addition of butadiene rubber did not significantly affect the conduction behavior of the electrolyte. Moreover, the conductivity of all the electrospun cloth electrolytes is much higher than that of the solution casting film.

Abstract: Yttria-stabilized zirconia (YSZ) thin films were deposited successfully using RF magnetron sputtering. The substrate had been used are sapphire glass. A pure ceramic of Zr-Y is synthesized and processed into a planar magnetron target which is reactively sputtered with an Argon-Oxygen gas mixture to form Zr-Y-O nanostructure. The aim of this research is to study the conductivity and roughness YSZ thin film by using RF magnetron sputtering by varying the temperature deposition parameter. By lowering the YSZ thin film into nanostructure would enable for SOFC to be operate at lower temperature below 400°C. The YSZ nanostructure were controlled by varying the deposition parameters, including the deposition temperature and the substrate used. The crystalline of YSZ structure at 100W and temperature 300°C. The surface morphology of the films proved that at 300°C temperature rate deposition showed optimum growth morphology and density of YSZ thin films. Besides, the high deposition subtrate temperature affected the thickness of YSZ thin film at 80nm by using surface profiler. A higher rate of deposition is achievable when the sputtering mode of the Zr-Y target is metallic as opposed to oxide. YSZ is synthesizing to obtain the optimum thin film for SOFC application.

Abstract: Dye Sensitized Solar Cells (DSSC) technology using inorganic electrolytes post problem in solvent evaporation and iodine sublimation (corroding contacts) causing instability of cells. Application of low molecular oligomers is progressing recently for an improved performance. The electrolyte system was aimed for improving electrochemical stability using quasi-solid-state electrolytes from organic capped polymers. A photo-electrochemical cell was developed from bio-based polyurethane diol (PU) polymer electrolyte with Sodium iodide (NaI) as conducting electrolyte transport material. In this study, polyurethane-diol was modified with NaI cations in the hydrothermal chemical reaction to form modified polyurethane-diol electrolyte. The chemical structure of polyurethane-diol and NaI have achieved highest conductivity of 8.06x10^-5 S.cm^-1 where structural of polyurethane-diol with NaI shown redox Fermi vectorial energy transfer evaluated for performance of efficiency. Stable cell for DSSC system require material properties to be invidually optimized in views of various elemential performances and solar cell of FTO/TiO-Pc/PU-NaI-I₂/Ac give a response under light intensity of 100 mW cm⁻² and indicated efficiency of power generation of 4 mW where photovoltaic effect of current density, Jsc of 0.04 mA.cm⁻² and open circuit voltage, Voc of 0.4 V respectively.

Abstract: This paper examines the impact of type of electrolyte solutions, standing time without electricity on the reinforced bond of the concrete of different water cement ratio before and after chloride extraction, processes the microscopic structure and mechanism analysis. The electrochemistry method can discharge the chlorine salt without destroying the original concrete protective layer and realize the non-loss, low cost and fast repair for the concrete structure destroyed by the chlorine salt corrosion. The results show a substantial loss of the reinforced bond (70-76%) after chloride extraction according to the concrete of different water cement ratio, and the decrease is in proportion to the current-on time and the electrochemical capacity of the electrolyte. The increased partial porosity of the cathode area of the concrete by the chlorine and hydrogen produced in the process of electrochemical chlorine extraction, the decomposition and softening of the concrete hydration products with external field are the main reasons for the dramatic drop of the reinforce bond.

Abstract: Low temperature fuel cells are promising environment-friendly energy conversion systems with high energy density and efficiency to be used as components of electronic devices for stationary and portable applications. In this paper, the key materials of the three types low temperature fuel cells are introduced, and the most recent advances related to the key materials and their character are reviewed. The current status of materials for electrolyte, catalyst and electrode materials is focused on.

Abstract: We investigated the electrochemical behavior and properties of lithium titanate oxide as the negative electrode for calcium ion batteries during charge/discharge tests in tetrahydrofuran (THF)-based electrolyte. The reversible charge and discharge capacities of ~150 and ~145 mAh g^–1 were observed, respectively, in THF-based electrolyte. They are larger than those obtained in propylene carbonate-based electrolyte. Moreover, interesting charge/discharge curves were observed, which might be attributed to structural changes during the insertion/extraction of calcium ions. These results were confirmed by the charge/discharge curves and scanning electron microscopy images.

Abstract: In this article, the electrochemical properties of elemental sulfur dissolved in alkaline solution has been studied for the first time using the method of removing the anodic and anodic-cathodic potentiodynamic polarization curves on rhodium electrodes. The influences of different parameters for oxidation process of elemental sulfur, namely sulfur component in electrolyte concentration, scan rate and temperature were investigated. The resulting polarogram presented in oxidation reaction of polysulfide ions to elemental sulfur process. This shows that polysulfide-ions in electrolyte at cathodic polarization was restored to monosulfide, and monosulfide –ions oxidized to elemental sulfur. The effective activation energy was calculated which equals 13,67 Kj/mol, indicating the oxidation reaction of sulfur occurred in diffusion mode.

Abstract: In this work, we present the effect of preparation temperature of electrolytes for fabricating undoped and silver (Ag) doped titanium dioxide (TiO₂) nanotubes by the electrochemical anodic oxidation of pure titanium sheets in electrolytes, mixtures of ethylene glycol (EG), ammonium fluoride (NH₄F) and deionized water, that contain with different of silver ions. Heat treatment of electrolytes was carried out at 100 °C during preparation process. The morphology and structure of prepared nanotubes were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). The structures of TiO₂ nanotubes obtained from heat treatment and non-heat treatment of electrolyte solutions and adding silver ions in electrolyte solution are similar. The nanotubes appear in arrays and the diameters of nanotubes were about 92 nm for non-heat treatment electrolyte solution and undoped TiO₂ and about 102 nm for heat treatment electrolyte solution and all Ag-doped TiO₂ nanotube arrays. When the concentration of silver nitrate (AgNO₃) increases, the TiO₂ nanotube arrays cracked and are not well arranged.

Abstract: Effect of glucose loading on the synthesis mesoporous carbon had been studied using hard template method where mesoporous silica SBA-15 was used as a template. To obtain a large pore of mesoporous carbon sample, a large pore of silica template was used. A series of mesoporous carbon sample was synthesized by loading different amounts of glucose (2.5g, 5.0g and 10.0g) as a carbon precursor to ensure that the template was fully impregnated with precursor. After treatment process, the surface area of carbon samples were measured with Brunauer-Emmett-Teller (BET) analysis and it shows that higher amount of glucose gives higher surface area due to the large pore of the template used. The samples then were tested with cyclic voltammetry technique at different scan rates (10, 20, 30 and 50 mVs^-1) in 6M KOH electrolyte. It reveals that higher surface area samples show a higher specific capacitance with 119 F/g at slow scan rate 10 mVs^-1.