scholarly journals Electrophoretic Deposition of Aluminum Nitride from Its Suspension in Acetylacetone Using Iodine as an Additive

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Bizuneh Workie ◽  
Brian E. McCandless ◽  
Zewdu Gebeyehu

We have studied electrophoretic deposition of AlN from its suspension in acetylacetone with I2as an additive. AlN powder with particle size <10 μm is dispersed to produce a positive charge and deposited on the cathode by applying fields greater than 10 V/cm between the electrodes. X-ray diffraction and FTIR studies indicate that the AlN before and after deposition has the same composition and structure. An increase in the amount of AlN in the suspension, the deposition potential, and the deposition time results in a linear increase in the weight of the AlN deposited. Electrophoretic deposition from 10 g/L AlN suspension shows an initial increase in the weight of AlN deposited with the concentration of I2, and the weight of AlN decreases after reaching a maximum at 0.20 g/L I2.

2007 ◽  
Vol 72 (3) ◽  
pp. 275-287 ◽  
Author(s):  
Marija Djosic ◽  
Vesna Miskovic-Stankovic ◽  
Vladimir Srdic

An aqueous boehmite sol was prepared by the peptization of Al(OH)3. The electrophoretic deposition of boehmite coatings on titanium from the aqueous sol was performed at a constant voltage (from 1.0 to 10 V) and for a constant deposition time (from 10 to 30 min). Increasing the applied voltage and deposition time increased the mass of the boehmite coating. It was shown that boehmite coatings of maximum thickness, low porosity and good adhesion can be formed at lower deposition voltages and longer deposition times. The boehmite powder, obtained by drying the prepared aqueous sol, and the boehmite coatings were thermally treated at 1000 ?C and 1300 ?C with a holding period of 1 h at the maximum temperature. X-Ray diffraction analysis of the thermally treated samples confirmed the existence of ?-Al2O3 and ????Al2O3 phases, respectively, while scanning electron microscopy revealed the graininess of the structure of the ?-Al2O3 coatings treated at 1300 ?C, indicating a significantly lower sintering temperature of the boehmite coating obtained by electrophoretic deposition.


2021 ◽  
Vol 1032 ◽  
pp. 51-56
Author(s):  
Fei Han ◽  
Xi Ping Xi ◽  
Min Fan ◽  
Ling Ling Wang ◽  
Jin Ming Shi ◽  
...  

In the paper, a novel perovskite microcrystalline with a capsule-free cavity box structure was creatively prepared through solvent thermal reaction, and the composition and structure of CH3NH3PbI3 perovskite microcrystalline were further characterized by scanning electron microscope (SEM) and energy dispersive X-ray (EDX) element mapping. The SEM results show that the grain size of the prepared CH3NH3PbI3 perovskite microcrystalline is more than 100 μm. Furthermore, X-ray diffraction (XRD) analysis was used to characterize the material decomposition of perovskite microcrystals before and after 150 d of air aging. The XRD results indicate the prepared perovskite microcrystalline could be stably preserved in the air for 150 d without degradation. Our method provides technical guidance for further enriching the morphology of CH3NH3PbI3 perovskite microcrystalline.


2008 ◽  
Vol 368-372 ◽  
pp. 1825-1827
Author(s):  
Wei Lin ◽  
Chang An Wang ◽  
Yong Huang

Electrophoretic deposition (EPD) has been widely studied in preparing clay-modified electrodes (CMEs) and in assembly of nano-laminated composite that mimics nacre. In this paper, the hydrothermal intercalation and EPD were combined to prepare CMEs with a uniform and continuous polymer/clay composite film of brick-and-mortar nano-laminated structure. X-ray diffraction, scanning electronic microscopy and thermal gravimetric analysis were employed to characterize the structure and composition of the films. Stability of aqueous suspension, temperature for hydrothermal intercalation and deposition time, etc. were systematically studied and discussed.


Coatings ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1192
Author(s):  
Imen Azzouz ◽  
Joël Faure ◽  
Kaouther Khlifi ◽  
Ahmed Cheikh Larbi ◽  
Hicham Benhayoune

In this paper, 45S5 Bioglass® coatings were elaborated by electrophoretic deposition (EPD) on the titanium alloy Ti6Al4V. An adequate grinding protocol was developed to obtain a stable suspension of submicrometric particles in isopropanol. The voltage and the deposition time of EPD were optimized. An optimal voltage of 30 V and two deposition times (30 and 90 s) were chosen to obtain two different coatings with thicknesses of 21 and 85 µm, respectively. The as-deposited coatings were thermally treated following a two-step protocol: one hour at 120 °C followed by one hour at 450 °C. The surface morphology and the chemical analysis of the 45S5 Bioglass® coatings were assessed, before and after heat treatment, by scanning electron microscopy associated to X-ray microanalysis (SEM-EDXS). Their structural analysis was performed by X-ray diffraction (XRD). A scratch test study was developed for mechanical properties analysis. The obtained results revealed that the obtained coatings were homogeneous, weakly crystallized with an important compactness. An increase in the critical load LC associated with the cohesive limit of the film (from Lc = 3.39 N to Lc = 5.18 N) was observed when the coating thickness was decreased from 85 to 21 µm. After the thermal treatment, the chemical composition of the coatings was not altered, and their mechanical properties were improved.


2012 ◽  
Vol 706-709 ◽  
pp. 617-622
Author(s):  
Rong Ma ◽  
Igor Zhitomirsky

Electrophoretic deposition method has been developed for the fabrication of organic-inorganic composite films, containing bioglass and hydroxyapatite in a hyaluronic acid matrix. The film composition and deposition yield were varied by variation of the electrochemical bath composition and deposition time. The films were studied by scanning electron microscopy, thermogravimetric analysis and X-ray diffraction methods. The deposition method offers the advantages of room temperature processing and allows the fabrication of composite films for biomedical applications.


Clay Minerals ◽  
1994 ◽  
Vol 29 (2) ◽  
pp. 169-178 ◽  
Author(s):  
A. Akelah ◽  
P. Kelly ◽  
S. Qutubuddin ◽  
A. Moet

Abstract‘Epoxyphilic’ montmorillonites were prepared containing various functional groups which can react with one or both of the components in amine-cured epoxy formulations. The preparation involves the ion exchange of six organic ammonium compounds containing either carboxylic acid, anhydride, phenolic hydroxyl, alcoholic hydroxyl, amide or amine functional groups. X-ray diffraction, elemental analysis and FTIR studies confirm the intercalation of the organic cations to form epoxyphilic montmorillonites. The adsorption behaviour of the modified montmorillonites are compared with the unmodified montmorillonite in an epoxy resin before and after the curing process.


Author(s):  
T. Gulik-Krzywicki ◽  
M.J. Costello

Freeze-etching electron microscopy is currently one of the best methods for studying molecular organization of biological materials. Its application, however, is still limited by our imprecise knowledge about the perturbations of the original organization which may occur during quenching and fracturing of the samples and during the replication of fractured surfaces. Although it is well known that the preservation of the molecular organization of biological materials is critically dependent on the rate of freezing of the samples, little information is presently available concerning the nature and the extent of freezing-rate dependent perturbations of the original organizations. In order to obtain this information, we have developed a method based on the comparison of x-ray diffraction patterns of samples before and after freezing, prior to fracturing and replication.Our experimental set-up is shown in Fig. 1. The sample to be quenched is placed on its holder which is then mounted on a small metal holder (O) fixed on a glass capillary (p), whose position is controlled by a micromanipulator.


2008 ◽  
Vol 59 (9) ◽  
Author(s):  
Violeta Vasilache ◽  
Gheorghe Gutt ◽  
Traian Vasilache

The electrochemical deposition of zinc and combinations with elements of the 8th group of the Periodic System (nickel, cobalt, iron) have good properties for anticorrosive protection, compared with pure zinc. For steel pieces, these films delay apparition and formation of white and red iron oxide. We used solutions with different concentrations of zinc chloride, nickel chloride and potassium chloride. To analyze the results we used the optic microscope and the X-ray diffraction.


2011 ◽  
Vol 314-316 ◽  
pp. 273-278
Author(s):  
Yu Hua Dong ◽  
Ke Ren ◽  
Qiong Zhou

Linear low density polyethylene (LLDPE) was chemically modified with grafting maleic anhydride (MAH) monomer on its backbone by melting blending. Nano-particles SiO2 was modified by cationic surfactant hexadecyl trimethyl ammonium bromide (CTAB) and anionic surfactant sulfosalicylic acid (SSA) and added to PE coating respectively. Measurement of membrane potential showed that the coating containing modified SiO2 nano-particles had characteristic of ion selectivity. The properties of the different coatings were investigated according to relative industrial standards. Experimental results indicated that PE coating with ion selectivity had better performances, such as adhesion strength, cathodic disbonding and anti-corrosion, than those of coating without ion selectivity. Crystal structure of the coatings before and after alkali corrosion was characterized by Fourier transform infrared spectra (FTIR) and X-ray diffraction (XRD). Structure of the coating without ion selectivity was damaged by NaOH alkali solution, causing mechanical properties being decreased. And the structure of the ion selective coatings was not affected.


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