Electrophoretic Deposition of Nanocrystalline BaTiO3 in Ethanol Medium

2006 ◽  
Vol 314 ◽  
pp. 133-140 ◽  
Author(s):  
Aydin Dogan ◽  
Göktuğ Günkaya ◽  
E. Suvaci ◽  
Markus Niederberger

Electrophoretic deposition technique is a versatile coating method. With this method not only flat surfaces but also curved or rough surfaces can be coated in various thicknesses. In this study, BaTiO3 nanocrystals were synthesized with a novel nonaqueous method. In a simple one pot reaction process, the metallic barium is directly dissolved in benzyl alcohol at slightly elevated temperatures. After the addition of titanium isopropoxide and subsequent solvothermal treatment nearly spherical BaTiO3 nanocrystals typically 5 nm in diameter were obtained. The stability of the suspension in ethanol and nanocrystalline particle size distribution was measured by Malvern Nano-ZS. The BaTiO3 suspensions were directly used in an electrophoretic deposition process without any additional operation. Pt plated alumina was used as substrate. Various voltages were applied by altering the cathode to anode distance as well as deposition time for optimal process control. Because of the ethanol adsorbed on the surface of the nanoparticles, application of high voltages was possible without causing hydrolysis. The deposited surface coatings were dried in air atmosphere and sintered at different temperatures. SEM, EDX and XRD analysis were employed for the investigation of the coating.

2013 ◽  
Vol 832 ◽  
pp. 633-638
Author(s):  
Khatijah Aisha Yaacob ◽  
David Jason Riley

Many researches on electrophoretic deposition of TiO2 nanoparticles (NPs) use commercial TiO2 nanoparticles from Degussa. TiO2 from Degussa is not use in this research because in order to make the TiO2 nanoparticle electronically charged and move under an applied constant voltage, a small amount of iodine and acetylacetone needs to be added to the suspension. It is suggested that the H+ ions generated by the reaction is absorbed on the suspended particles making them positively charged. For anodic EPD, negatively charged nanoparticles are required. In this research TiO2 nanoparticles were prepared by adding 1 ml of titanium isopropoxide dilute with 1 ml ethanol to 10 ml DI water and stirrer under 0°C for 4 hr. As prepared TiO2 nanoparticle were centrifuged at 5500 rpm for 10 min to isolate the particles from the solution. Then the TiO2 nanoparticles were resuspended in ethanol or water. TiO2 nanoparticle with particle diameter of 4.66 nm and anatase phase were produced. Important electrophoretic deposition process parameters, such as apparent pH of the TiO2 NPs, applied voltage, deposition time and solid loading, were studied during electrophoretic deposition of TiO2 nanoparticles.


2012 ◽  
Vol 2012 ◽  
pp. 1-17 ◽  
Author(s):  
M. Selin Sunay ◽  
Onder Pekcan ◽  
Saziye Ugur

Steady-state fluorescence (SSF) technique in conjunction with UV-visible (UVV) technique and atomic force microscope (AFM) was used for studying film formation from TiO2covered nanosized polystyrene (PS) latex particles (320 nm). The effects of film thickness and TiO2content on the film formation and structure properties of PS/TiO2composites were studied. For this purpose, two different sets of PS films with thicknesses of 5 and 20 μm were prepared from pyrene-(P-) labeled PS particles and covered with various layers of TiO2using dip-coating method. These films were then annealed at elevated temperatures above glass transition temperature () of PS in the range of 100–280°C. Fluorescence emission intensity, from P and transmitted light intensity, were measured after each annealing step to monitor the stages of film formation. The results showed that film formation from PS latexes occurs on the top surface of PS/TiO2composites and thus developed independent of TiO2content for both film sets. But the surface morphology of the films was found to vary with both TiO2content and film thickness. After removal of PS, thin films provide a quite ordered porous structure while thick films showed nonporous structure.


2013 ◽  
Vol 1514 ◽  
pp. 151-156
Author(s):  
Darío Pieck ◽  
Lionel Desgranges ◽  
Yves Pontillon ◽  
Pierre Matheron

ABSTRACTIn the present work, we focus on δ-Gd6UO12 phase and its stability under reducing conditions. This later point is interesting regarding reducing environment that could exist in some nuclear storage sites and that could possibly degrade δ–compounds. A polycrystalline δ-Gd6UO12 sample was prepared by sintering cubic-Gd2O3 and UO2 mixed powders under an air atmosphere. The resulting pellets were then characterized and reduced by heat treatment under an Ar with H2 5% atmosphere. XRD analysis of the sample after reduction did not confirm the reduction into Gd6UO11 but a decomposition of the δ-compound. Preliminary characterizations of these decomposition products are presented.


2018 ◽  
Vol 27 (01n02) ◽  
pp. 1840002 ◽  
Author(s):  
Machhindra Koirala ◽  
Jia Woei Wu ◽  
Adam Weltz ◽  
Rajendra Dahal ◽  
Yaron Danon ◽  
...  

We present a cost effective and scalable approach to fabricate solid state thermal neutron detectors. Electrophoretic deposition technique is used to fill deep silicon trenches with 10B nanoparticles instead of conventional chemical vapor deposition process. Deep silicon trenches with width of 5-6 μm and depth of 60-65 μm were fabricated in a p-type Si (110) wafer using wet chemical etching method instead of DRIE method. These silicon trenches were converted into continuous p-n junction by the standard phosphorus diffusion process. 10B micro/nano particle suspension in ethyl alcohol was used for electrophoretic deposition of particles in deep trenches and iodine was used to change the zeta potential of the particles. The measured effective boron nanoparticles density inside the trenches was estimated to be 0.7 gm cm-3. Under the self-biased condition, the fabricated device showed the intrinsic thermal neutron detection efficiency of 20.9% for a 2.5 × 2.5 mm2 device area.


Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1922 ◽  
Author(s):  
Lunzhi Li ◽  
Lisheng Zhong ◽  
Kai Zhang ◽  
Jinghui Gao ◽  
Man Xu

There is a long-standing puzzle concerning whether polyethylene blends are a suitable substitution for cable-insulation-used crosslinking polyethylene (XLPE) especially at elevated temperatures. In this paper, we investigate temperature dependence of mechanical, electrical properties of blends with 70 wt % linear low density polyethylene (LLDPE) and 30 wt % high density polyethylene (HDPE) (abbreviated as 70 L-30 H). Our results show that the dielectric loss of 70 L-30 H is about an order of magnitude lower than XLPE, and the AC breakdown strength is 22% higher than XLPE at 90 °C. Moreover, the dynamic mechanical thermal analysis (DMA) measurement and hot set tests suggest that the blends shows optimal mechanical properties especially at high temperature with considerable temperature stability. Further scanning electron microscope (SEM) observation and X-ray diffraction (XRD) analysis uncover the reason for the excellent high temperature performance and temperature stability, which can be ascribed to the uniform fine-spherulite structure in 70 L-30 H blends with high crystallinity sustaining at high temperature. Therefore, our findings may enable the potential application of the blends as cable insulation material with higher thermal-endurance ability.


2011 ◽  
Vol 1299 ◽  
Author(s):  
Ping Du ◽  
I-Kuan Lin ◽  
Yunfei Yan ◽  
Xin Zhang

ABSTRACTSilicon carbide (SiC) has received increasing attention on the integration of microelectro-mechanical system (MEMS) due to its excellent mechanical and chemical stability at elevated temperatures. However, the deposition process of SiC thin films tends to induce relative large residual stress. In this work, the relative low stress material silicon oxide was added into SiC by RF magnetron co-sputtering to form silicon oxycarbide (SiOC) composite films. The composition of the films was characterized by Energy dispersive X-ray (EDX) analysis. The Young’s modulus and hardness of the films were measured by nanoindentation technique. The influence of oxygen/carbon ratio and rapid thermal annealing (RTA) temperature on the residual stress of the composite films was investigated by film-substrate curvature measurement using the Stoney’s equation. By choosing the appropriate composition and post processing, a film with relative low residual stress could be obtained.


2013 ◽  
Vol 678 ◽  
pp. 193-197
Author(s):  
Periyasamy Gowthaman ◽  
Manickam Saroja ◽  
Muthusamy Venkatachalam ◽  
Jagadeesh Deenathayalan ◽  
N. Muthukumarasamy ◽  
...  

A novel and simple approach is reported to fabricate ZnO nanorods. Zinc acetate dihydrate, ethanol and de-ionized water were used to prepare seed layer. Zinc nitrate and hexamethylenetetramine solution were used for growth of ZnO nanorods. The ZnO nanorods were grown at two different temperatures of 90°C and 120°C and annealed at three different temperatures of 300°C, 400°C and 500°C in air atmosphere. Nanorod growth temperature and annealing temperature are varied and the corresponding changes in structural, morphological and optical properties were reported. The structure, orientation, surface morphology and optical properties of the ZnO nanorods were investigated by XRD, SEM & UV studies. The influence of growth and annealing temperatures on structural and optical properties were reported.


2015 ◽  
Vol 654 ◽  
pp. 218-223 ◽  
Author(s):  
Alexander Heinemann ◽  
Sven Koenen ◽  
Kerstin Schwabe ◽  
Christoph Rehbock ◽  
Stephan Barcikowski

Electrophoretic deposition of ligand-free platinum nanoparticles has been studied to elucidate how wettability, indicated by contact angle measurements, is linked to vital parameters of the electrophoretic deposition process. These parameters, namely the colloid concentration, electric field strength and deposition time, have been systematically varied in order to determine their influence on the contact angle. Additionally, scanning electron microscopy has been used to confirm the homogeneity of the achieved coatings.


Sign in / Sign up

Export Citation Format

Share Document