Application of sol-gel assisted ultrasound-induced atomisation in the mesostructuring of nickel aluminate UF membranes

Author(s):  
G.B. Kunde ◽  
B. Sehgal
2017 ◽  
Vol 757 ◽  
pp. 171-175
Author(s):  
Suntorn Sangsong ◽  
Kotchawan Srimala ◽  
Mia Radonjic ◽  
Sabaithip Tungkamani ◽  
Thana Sornchamni ◽  
...  

High temperature water gas shift (HT-WGS) is an important catalytic process connected with reforming process in hydrogen production. Ni/CeO2-Al2O3 (or Al2O3) catalysts were studied in this work on the effect of catalyst preparation method toward the physicochemical properties and the HT-WGS activity. Ni/CeO2-Al2O3 were prepared by sol-gel and impregnation methods whereas Ni/Al2O3 was prepared by impregnation method. The catalyst samples were characterized by XRD, H2-TPR and H2-TPD techniques. The catalytic activities of HT-WGS catalysts was demonstrated at 550°C, GHSV of 2x105 mLh-1gcat-1and steam-to-CO ratio of 3. Nickel was detected as a nickel aluminate phase in the calcined catalyst. Ni strongly interacted with support in the calcined catalyst prepared by sol-gel method. The strong metal-support interaction can be resisted by preparing catalyst via impregnation and CeO2 can promote the H2O dissociation in HT-WGS mechanism. The highest metal dispersion, largest metal surface area and greatest HT-WGS activity were consequently achieved by Ni/CeO2-Al2O3 prepared from impregnation method.


Author(s):  
C. Otero Areán ◽  
M. Peñarroya Mentruit ◽  
A.J. López López ◽  
J.B. Parra

2019 ◽  
Vol 48 (5) ◽  
pp. 2932-2939 ◽  
Author(s):  
Md Atiqur Rahman ◽  
Mohammad Rashed Iqbal Faruque ◽  
Mohammad Tariqul Islam

2016 ◽  
Vol 42 (12) ◽  
pp. 7909-7921 ◽  
Author(s):  
Samane Komeili ◽  
Abbas Taeb ◽  
Maryam Takht Ravanchi ◽  
Maryam Rahimi Fard
Keyword(s):  
Sol Gel ◽  

2013 ◽  
Vol 64 ◽  
pp. 167-177 ◽  
Author(s):  
B. Gunduz ◽  
Ahmed A. Al-Ghamdi ◽  
A.A. Hendi ◽  
Zarah H. Gafer ◽  
S. El-Gazzar ◽  
...  

Author(s):  
George C. Ruben ◽  
Merrill W. Shafer

Traditionally ceramics have been shaped from powders and densified at temperatures close to their liquid point. New processing methods using various types of sols, gels, and organometallic precursors at low temperature which enable densificatlon at elevated temperatures well below their liquidus, hold the promise of producing ceramics and glasses of controlled and reproducible properties that are highly reliable for electronic, structural, space or medical applications. Ultrastructure processing of silicon alkoxides in acid medium and mixtures of Ludox HS-40 (120Å spheres from DuPont) and Kasil (38% K2O &62% SiO2) in basic medium have been aimed at producing materials with a range of well defined pore sizes (∼20-400Å) to study physical phenomena and materials behavior in well characterized confined geometries. We have studied Pt/C surface replicas of some of these porous sol-gels prepared at temperatures below their glass transition point.


Author(s):  
V. Kaushik ◽  
P. Maniar ◽  
J. Olowolafe ◽  
R. Jones ◽  
A. Campbell ◽  
...  

Lead zirconium titanate films (Pb (Zr,Ti) O3 or PZT) are being considered for potential application as dielectric films in memory technology due to their high dielectric constants. PZT is a ferroelectric material which shows spontaneous polarizability, reversible under applied electric fields. We report herein some results of TEM studies on thin film capacitor structures containing PZT films with platinum-titanium electrodes.The wafers had a stacked structure consisting of PZT/Pt/Ti/SiO2/Si substrate as shown in Figure 1. Platinum acts as electrode material and titanium is used to overcome the problem of platinum adhesion to the oxide layer. The PZT (0/20/80) films were deposited using a sol-gel method and the structure was annealed at 650°C and 800°C for 30 min in an oxygen ambient. XTEM imaging was done at 200KV with the electron beam parallel to <110> zone axis of silicon.Figure 2 shows the PZT and Pt layers only, since the structure had a tendency to peel off at the Ti-Pt interface during TEM sample preparation.


Author(s):  
J.M. Schwartz ◽  
L.F. Francis ◽  
L.D. Schmidt ◽  
P.S. Schabes-Retchkiman

Ceramic thin films and coatings are of interest for electrical, optical, magnetic and thermal barrier applications. Critical for improved properties in thin films is the development of specific microstructures during processing. To this end, the sol-gel method is advantageous as a versatile processing route. The sol-gel process involves depositing a solution containing metalorganic or colloidal ceramic precursors onto a substrate and heating the deposited layer to form a crystalline or non-crystalline ceramic coating. This route has several advantages, including the ability to create tailored microstructures and properties, to coat large or small areas, simple or complex shapes, and to more easily prepare multicomponent ceramics. Sol-gel derived coatings are amorphous in the as-deposited state and develop their crystalline structure and microstructure during heat-treatment. We are particularly interested in studying the amorphous to crystalline transformation, because many key features of the microstructure such as grain size and grain size distribution may be linked to this transformation.


Author(s):  
P. G. Kotula ◽  
D. D. Erickson ◽  
C. B. Carter

High-resolution field-emission-gun scanning electron microscopy (FESEM) has recently emerged as an extremely powerful method for characterizing the micro- or nanostructure of materials. The development of high efficiency backscattered-electron detectors has increased the resolution attainable with backscattered-electrons to almost that attainable with secondary-electrons. This increased resolution allows backscattered-electron imaging to be utilized to study materials once possible only by TEM. In addition to providing quantitative information, such as critical dimensions, SEM is more statistically representative. That is, the amount of material that can be sampled with SEM for a given measurement is many orders of magnitude greater than that with TEM.In the present work, a Hitachi S-900 FESEM (operating at 5kV) equipped with a high-resolution backscattered electron detector, has been used to study the α-Fe2O3 enhanced or seeded solid-state phase transformations of sol-gel alumina and solid-state reactions in the NiO/α-Al2O3 system. In both cases, a thin-film cross-section approach has been developed to facilitate the investigation. Specifically, the FESEM allows transformed- or reaction-layer thicknesses along interfaces that are millimeters in length to be measured with a resolution of better than 10nm.


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