scholarly journals Demonstration of the Use of 3D X-ray Tomography to Compare the Uniformity of Catalyst Coatings in Open-Cell Foams

2018 ◽  
Vol 2 (4) ◽  
pp. 52
Author(s):  
Marie-Line Zanota ◽  
Stéphanie Pallier ◽  
Anaïs Dousse ◽  
Joël Lachambre ◽  
Valérie Meille

Coating open-cell foams by a catalytic layer is a necessary step to obtain structured catalytic foam reactors. The dip-coating method, consisting of immersing the foam in a suspension or in a sol-gel, is generally used to obtain the coating. The excess of liquid has to be evacuated from the foam to obtain a thin layer. Different methods to remove this excess of liquid have been investigated in the present work. The objective was to show that 3D X-ray tomography coupled to image analysis could be a tool to discriminate the methods by analysing the spatial localisation of the catalyst layer throughout the whole foam samples. A simple blowing by air in every direction seems to not be appropriate to obtain uniform coatings.

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
V. L. Chandraboss ◽  
B. Karthikeyan ◽  
J. Kamalakkannan ◽  
S. Prabha ◽  
S. Senthilvelan

The TiO2/SiO2 and ZnO/SiO2 composite films were prepared by sol-gel dip coating method. The surface morphology and crystal structure of thin films were characterized by means of scanning electron microscopy (SEM) with elementary dispersive X-ray analysis (EDX) and X-ray diffractometer (XRD). Optical properties of films have been investigated using ultraviolet and visible spectroscopy (UV-visible spectroscopy). The photocatalytic activity was established by testing the degradation and decolorization of methyl green (MG) from aqueous solution with artificial UV-light.


2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
B. Sadeghi ◽  
R. Sarraf-Mamoory ◽  
H. R. Shahverdi

LiMn2O4spinel cathode materials have been successfully synthesized by solid-state reaction. Surface of these particles was modified by nanostructured LiFePO4via sol gel dip coating method. Synthesized products were characterized by thermally analyzed thermogravimetric and differential thermal analysis (TG/DTA), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy dispersive X-ray spectroscopy (EDX). The results of electrochemical tests showed that the charge/discharge capacities improved and charge retention of battery enhanced. This improved electrochemical performance is caused by LiFePO4phosphate layer on surfaces of LiMn2O4cathode particles.


2016 ◽  
Vol 848 ◽  
pp. 717-721
Author(s):  
Li Yun Chen ◽  
Xiao Ping Liao ◽  
Wei Zhong Jiang ◽  
Jia Yi Ye ◽  
Hui Le Jin ◽  
...  

nanosize TiO2/SiO2 thin films were deposited by sol-gel dip-coating method on enamel substrates. Crystal structure, micro-structure, hydrophilic property, gloss property was investigated by X-ray diffract meter, scanning electron microscope, CCD camera, enamel gloss meter. The results show that the hydrophilic property of the enamel was greatly increased by heating the enamel with coating TiO2/SiO2 film; the gloss property of the enamel surface greatly increased after the enamel coated with TiO2/SiO2 film. The main crystals in TiO2/SiO2 film on the enamel were anatase when the baking temperature was below the 700°C.


2013 ◽  
Vol 734-737 ◽  
pp. 2155-2158 ◽  
Author(s):  
Yun Hai Wang ◽  
Zi Zhou Nie ◽  
Yong Rong Liang

Nickel and antimony doped tin oxide (NATO) electrodes were prepared by sol-gel dip-coating method. The effect of doping levels was investigated via scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD). The electrochemical ozone generation efficiency was also tested. The results showed that sol-gel prepared electrodes had a smoother surface morphology and lower current efficiency for ozone generation than electrodes prepared by traditional pyrolysis method. The nickel and antimony doping lead to a decrease in the crystallites size, while its effects on ozone generation efficiency were complex.


2011 ◽  
Vol 299-300 ◽  
pp. 448-451
Author(s):  
Guo Chao Qi ◽  
Sam Zhang ◽  
Qiang Li ◽  
Feng Jun Shan ◽  
Jing Yuan Yu ◽  
...  

A series of the magnesium apatite coatings according to (Ca10-xMgx)(PO4)6(OH)2, where x = 0 to 2, was synthesized through a sol-gel dip-coating method. The roughness of the magnesium coatings increased as more magnesium incorporated into the coatings. The mechanical properties of the coatings were analyzed with Nanoindentor. The incorporation of magnesium decreased the hardness and the Young’s modulus of the coating. The X-ray Photoelectron Spectroscopy (XPS) analysis revealed that only part of magnesium was incorporated into the apatite structure while the rest existed in the form of MgO in the coating.


2011 ◽  
Vol 299-300 ◽  
pp. 508-511
Author(s):  
Guo Chao Qi ◽  
Feng Jun Shan ◽  
Qiang Li ◽  
Jing Yuan Yu ◽  
Qu Kai Zhang

Magnesium apatite (MA, (Ca9Mg)(PO4)6(OH)2) and Hydroxyapatite (HA) coatings were synthesized on Ti6Al4V substrates by a sol-gel dip coating method. Glucose and bovine serum albumin (BSA) were added to the standard simulated body fluid (SBF) separately to form organic-containing simulated body fluids. MA and HA coatings were immersed in standard and organic modified SBF for time periods of 4, 7, 14, 21 and 28 days at 37±1°C. The surface dissolution and deposition behavior of the coatings after soaking were examined with Scanning Electron Microscopy (SEM) and X-ray Photoelectron Spectroscopy (XPS). The results show that glucose in SBF has no apparent effect on the deposition of new apatite from the solution. BSA in SBF shows retardation effect on the deposition of apatite by forming a protein dominant globular layer. This layer inhibits the further deposition of apatite from SBF solution.


2012 ◽  
Vol 557-559 ◽  
pp. 1691-1694 ◽  
Author(s):  
Qi Fu Bao ◽  
Wei Xia Dong ◽  
Jian Er Zhou

Smooth and dense films of CaTiO3 were prepared on the glass substrate by a sol-gel dip coating method. Characterization of the product was carried out by different techniques such as powder X-ray diffraction (XRD), scanning electron microscope (SEM) and UV–vis optical spectroscopy. The results showed that pH and water contents had a great influence on morphology of CaTiO3 film. When water content is 0.128 mol at PH=1.56, CaTiO3 film presents an absorption in the UV region and the band gap is estimated to 3.35 ev. The results show the large potential of this material in electronic structure.


2000 ◽  
Vol 628 ◽  
Author(s):  
Kazuki Nakanishi ◽  
Souichi Kumon ◽  
Kazuyuki Hirao ◽  
Hiroshi Jinnai

ABSTRACTMacroporous silicate thick films were prepared by a sol-gel dip-coating method accompanied by the phase separation using methyl-trimethoxysilane (MTMS), nitric acid and dimethylformamide (DMF) as starting components. The morphology of the film varied to a large extent depending on the time elapsed after the hydrolysis until the dipping of the coating solution. On a glass substrate, the films prepared by early dipping had inhomogeneous submicrometer-sized pores on the surface of the film. At increased reaction times, relatively narrow sized isolated macropores were observed and their size gradually decreased with the increase of reaction time. On a polyester substrate, in contrast, micrometer-sized isolated spherical gel domains were homogeneously deposited by earlier dippings. With an increase of reaction time, the volume fraction of the gel phase increased, then the morphology of the coating transformed into co-continuous gel domains and macropores, and finally inverted into the continuous gel domains with isolated macropores. The overall morphological variation with the reaction time was explained in terms of the phase separation and the structure freezing by the forced gelation, both of which were induced by the evaporation of methanol during the dipping operation.


2006 ◽  
Vol 317-318 ◽  
pp. 807-810 ◽  
Author(s):  
Chang Yeoul Kim ◽  
Jin Wook Choi ◽  
Tae Yeoung Lim ◽  
Duck Kyun Choi

Electrochromic WO3 thin film was prepared by using tungsten metal solution in hydrogen peroxide as a starting solution and by sol-gel dip coating method. XRD pattern showed that tungsten oxide crystal phase formed at 400. In the view of electrochemical property, WO3 thin film which was heat-treated at 300 and was amorphous had better than that of the crystalline phase.


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