Papers by Keyword: Electrophoretic Deposition (EPD)

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Authors: Virginia Martina, M. Federica de Riccardis, Daniela Carbone
Abstract: Poly(etherether-ketone) (PEEK) suspensions in ethanol and isopropanol containing also α-alumina and hydroxyapatite powders were studied. An innovative method was used in the study of the quality of suspensions. We studied suspensions by means of zeta potential and grain-size measurements. The comparison amongst the different suspensions was carried out by using statistical and chemometric tools, especially by the use of an explorative test based on the Principal Component Analysis (PCA). The chemometric analysis was performed by involving different combinations of each type of powder and each type of solvent.
Authors: Takaharu Watanabe, Shun Fukutomi, Kozo Taguchi
Abstract: This study examines two things about a dye sensitized solar cell (DSSC) to improve power conversion efficiency. One is how to make ZnO-coated TiO2 electrode. The other is how to make carbon nanotube (CNT) electrode. First, we considered the process of making the ZnO-coated TiO2 electrode of the DSSC. This ZnO coating of the DSSC is important for the increase of power conversion efficiency. The fabrication method of the ZnO-coated TiO2 electrode was simple dip coating. This method uses the immerse of the zinc acetate dehydrate [Zn (CH3COO2)・2H2O] solution. This method can make the cheap ZnO-coated TiO2 electrode. However, this method has a slightly negative effect, which is filling in holes of the porous TiO2 layer. We tried to improve this negative effect. We changed the concentration of a zinc acetate dehydrate solution from low to high. Also, we changed the immersing time of the zinc acetate dehydrate solution. We did the control of the band gap of ZnO-coated TiO2 electrode of DSSC for increasing power conversion efficiency. Second, we substituted CNT for counter electrodes to improve the performance of DSSC. As a manufacture method of CNT electrode, we used electrophoretic deposition (EPD). After that, we baked this CNT electrode and measured its specific surface area. We tried to improve specific surface area by changing baking temperature.
Authors: Elizabeth C. Kolos, Andrew Ruys, Greg J. Roger
Authors: Kanta Sugii, Kazuaki Tamiya, Kozo Taguchi
Abstract: Dye Sensitized Solar Cell (DSSC) is more inexpensive and ecofriendly than silicone solar cell from structure. It has been reported that DSSC made by used ruthenium reaches 10.7 % [1]. However there are some contradiction so that a pigment named Ruthenium complex which is toxic is used in it. So we investigated to solve these problems using MK-II dye that is inexpensive and harmless. At the same time, we explored what kind of influence in conversion efficiency from difference of coating thickness by Electrophoretic Deposition (EPD) method. This method can lead to use flexible materials [2]. Because letting to deposit Titanium oxide (TiO2), we can lower sintering temperature or less to plastic melting point. The result was cell’s conversion efficiency better than others in case of 90sec and 100sec of electrophoresis time. From our experiments it is able to be said that coating thickness made by 90sec and 100sec are suitable, and its difference affect conversion efficiency.
Authors: Y. Yamamoto, Hirotaka Maeda, H. Shibutani, H. Suzuki, O. Horiuchi
Authors: Reza Riahifar, Babak Raissi, Ehsan Marzbanrad, Cyrus Zamani
Abstract: Deposition of ceramic nanoparticles (dispersed in non-aqueous suspension) on in-plane electrodes and under the influence of AC electric fields in the frequency range of 0.01 Hz - 10 kHz is investigated. Analysis of the particle response to the applied field is a difficult task due to the mutual effect of electric and hydrodynamic forces which are present in the system. In this work, however, we show the possibility of dividing the frequency range into four domains with four distinct governing mechanisms. Possible mechanisms are suggested and dominant forces are determined for each domain. In situ optical microscopy observations are used for visualization of nanoparticles´ movement dispersed in liquid medium. These observations show that applying AC electrophoresis at frequencies below 10 kHz is an effective way for manipulating ceramic nanoparticles and device fabrication.
Authors: Guido Falk, Alexander Nold, Birgit Wiegand
Abstract: The processing of ceramic thick and thin films, nano- and micro-scaled ceramic structures as well as bulk ceramics of high quality and precise dimensions under electrophoretic boundary conditions requires a full understanding of the dynamics of relevant interfacial mechanisms and interactions of colloidal phases at the nano- and micro-scale. Recent findings and latest insights on the importance of electrokinetic and electrohydrodynamic interfacial processes for membrane electrophoretic depositon in aqueous media are summarised. In this context, the paper addresses the fundamental importance of surficial charge heterogeneities, electric double layer instabilities, electrokinetically induced micro-vortex dynamics, as well as lateral and medial effective electrical field gradients. These phenomena are evaluated in terms of reasonable correlations and mechanistic coincidences of general EPD deposition principles. The experimental results are based on potentiometry, in-situ videomicroscopy, high-resolution as well as secondary electron microscopy. A numerical method for the simulation of the electrophoretic deposition process is suggested based on a multiphysical Finite Element approach given by Nernst-Planck, Poisson- and Navier-Stokes equations. The results of the simulations provide adequate agreement with experimental findings.
Authors: J.A. Escribano, Isabel Gonzalo-Juan, Antonio Javier Sanchez-Herencia, Begoña Ferrari
Abstract: In this study, coatings with irregular nanotopography prepared by electrophoretic deposition (EPD) in electro-polished surfaces are characterized. Films are composed by Yttria Stabilized Zirconia (YSZ) particles, 5-8 nm in size and spherical morphology, synthesized under hydrothermal conditions and re-dispersed in the post reaction medium. Growth behaviour of coatings with time, including array morphology, aggregation origin and activity, are explored by means of atomic force microscopy (AFM) and its different measurement modes. Arrangement of electrically driven particles at the nanoscale can be assessed through the topographic description of films prepared with increasing deposition times. Moreover, topography can be associated to the electrokinetic behaviour of particles and agglomeration degree of the suspension. The evaluation of particle junctions and then the quality of particle cohesion within the film can also be discerned by AFM characterization.
Authors: Iman Azarian Borojeni, Babak Raissi, Amir Maghsoudipour, Mahmood Kazemzad, Ehsan Marzbanrad
Abstract: In this research aging behaviors of yttria stabilized zirconia (YSZ) in non aqueous suspensions, namely ethanol, isopropanol, n-propanol, acetylacetone and the mixture of ethanol-acetylacetone were investigated. For this purpose, electrical conductivity, electrophoretic mobility and suspension stability during aging time (6 to 7 days) were evaluated. Except for the ethanol-acetyl acetone mixture, each suspension contained 0 to 0.8 g/L iodine. It was revealed that, the alcoholic suspensions indicated lower conductivity in comparison with acetylacetone suspensions. However, acetylacetone suspension showed lower conductivity variation with time. Although iodine could improve the electrophoretic mobility of ethanol and acetylacetone suspensions, it had little effect on electrophoretic mobility of isopropanol and n-propanol suspensions. Also, it was indicated that iodine as a dispersant was not helpful for alcoholic suspensions stability. It was concluded that the mixture of acetylacetone-ethanol suspension was the best candidate in this study for electrophoretic deposition of YSZ, owing to its little behavior variation with the aging time, low conductivity and high electrophoretic mobility. High quality crack-free layers were electrophoretically deposited from this suspension on the substrate by applying 50 V/cm electrical field.
Authors: Hynek Hadraba, Karel Maca, Zdeněk Chlup
Abstract: Electrophoretic deposition of Al2O3 and ZrO2 powders from isopropanol suspension in the presence of monochloroacetic acid under constant-current conditions was studied. The similar charge and electrophoretic mobility of Al2O3 and ZrO2 in the suspensions was found. Adjusting to properly controlled kinetics of deposition deposits were prepared of pre-defined thicknesses. In view of the negative charge of Al2O3 and ZrO2 particles in the isopropanol suspensions used, the prepared layers were deposited on the anode and thus they were not affected by possible solvent electrolysis, which contributed to their defect-free and low-porosity structure.
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