Sol-Gel Process form Heterometallic Alkoxides to Incorporate Alkaline- and Rare Earths in Alumina for automotive Applications

1996 ◽  
Vol 431 ◽  
Author(s):  
C. K. Narula
Keyword(s):  
Elevated Temperatures ◽  
Sol Gel ◽  
Automotive Applications ◽  
Automotive Catalysts ◽  
Heterometallic Alkoxides ◽  
Sol Gel Process ◽  
Alkaline Earths ◽  
Cost Of Materials ◽  
Gel Processing

AbstractThe high cost of materials prepared by sol-gel processing and the loss of useful surface properties at elevated temperature has prevented the application of sol-gel processed materials in automotive exhaust reduction catalyst formulations. In this report, we briefly describe the important developments needed in the next generation automotive catalysts and the role of sol-gel processed materials. We will also discuss the application of heterometallic alkoxides as sol-gel precursors to achieve the molecular distribution of lanthanides and alkaline earths in alumina matrices needed for the stabilization of alumina based materials at elevated temperatures.

scholarly journals Cyanate Ester Resin/Silica subnanocomposites and their superiority over nanocomposites due to fundamental role of constrained interfacial dynamics

2021 ◽  
Vol 2103 (1) ◽  
pp. 012100
Author(s):  
V A Bershtein ◽  
A M Fainleib ◽  
D A Kirilenko ◽  
P N Yakushev
Keyword(s):  
Positive Impact ◽  
Sol Gel ◽  
Cyanate Ester ◽  
Interfacial Dynamics ◽  
Cyanate Ester Resin ◽  
Sol Gel Process ◽  
Matrix Properties ◽  
Interfacial Areas ◽  
The Matrix

Abstract The study of nanostructure, thermal and relaxation properties (by HAADF-STEM, EDXS, DMA and DSC), combined with the calculations of interparticle distances and interfacial areas, has been performed for a series of the hybrid Cyanate Ester Resin (CER)/Si02 polymer composites with 0.01 to 10 wt.% Si02 units introduced via a sol-gel process. The absence of clusterization, arising only subnanometric Si02 nodes and their quasi-regular distribution within the amorphous matrix, with the shortest distances between nodes, provided their exceptional positive impact on the matrix properties at ultra-low Si02 contents of 0.03-0.1 wt.%. The superiority of these subnanocomposites over the nanocomposites was determined by the role of constrained interfacial dynamics over the whole matrix.

scholarly journals Role of Cr2O3 on the mullittization of di-phasic Al2O3-SiO2 gel

Cerâmica ◽  
2010 ◽  
Vol 56 (339) ◽  
pp. 273-278 ◽  
Author(s):  
Jagannath Roy ◽  
Narayan Bandyopadhyay ◽  
Santanu Das ◽  
Saikat Maitra
Keyword(s):  
Elevated Temperatures ◽  
Sol Gel ◽  
Inorganic Salts ◽  
Maximum Reduction ◽  
Analysis Measurement ◽  
Heat Treated ◽  
Maximum Improvement ◽  
Scanning Electron ◽  
Mullite Ceramics

Diphasic Al2O3-SiO2 gel was synthesized by sol-gel route from inorganic salts following aqueous phase colloidal interaction and the effect of Cr2O3 additive on the formation of mullite ceramics from this diphasic gel was investigated. The gel powder was thoroughly characterized by chemical analysis, measurement of surface area, bulk density and FTIR spectroscopy. The calcined gel was compacted with Cr2O3 additives in three different proportions (ca. 1, 2 and 3 wt%) and heat treated at different elevated temperatures (ca, 1400, 1500 and 1600 ºC). The analyses of microstructure and phase composition of the sintered masses were carried out by scanning electron microscopy and XRD technique. The morphology of the mullite crystals changed significantly in the presence of the additives. It has been observed that more than 7% more mullite has been formed with the addition of maximum 3% additive only. Using the additive, the maximum reduction in apparent porosity was about 30% and maximum improvement in density in the sintered compacts was about 14%. The flexural strength and fracture toughness of the sintered compacts also improved by 16% and 6% respectively in the presence of the Cr2O3 additive under the experimental condition.

The role of uranium(VI) in the ThO2UO3 SolGel process

1980 ◽  
Vol 78 (1) ◽  
pp. 155-162 ◽  
Author(s):  
Param H Tewari ◽  
Allan B Campbell
Keyword(s):  
Sol Gel ◽  
Sol Gel Process

Undoped and Doped Perovskite Films: Sol-Gel Processing and Characterization

1991 ◽  
Vol 243 ◽  
Author(s):  
Mareike Klee ◽  
Rainer Waser
Keyword(s):  
Crystal Structure ◽  
Field Strength ◽  
Remanent Polarization ◽  
Sol Gel ◽  
Insulation Resistance ◽  
Sol Gel Process ◽  
Gel Processing

AbstractThin undoped Pb(ZrxTi1−x)O3 (x=0.2-0.75), BaTiO3, SrTiO3 as well as acceptor (Mn, Ni) and donor (La, Ce) doped films with thicknesses of 0.2-1 μm have been deposited by a modified sol-gel process. The crystal structure and the morphology of the films as a function of the processing and composition were analyzed. The films were characterized with respect to their ferroelectric and dielectric properities e.g. permittivity, remanent polarization, coervice field strength, insulation resistance.

Ultrasmooth metal halide perovskite thin films via sol–gel processing

2016 ◽  
Vol 4 (21) ◽  
pp. 8308-8315 ◽  
Author(s):  
Ross A. Kerner ◽  
Lianfeng Zhao ◽  
Zhengguo Xiao ◽  
Barry P. Rand
Keyword(s):  
Thin Film ◽  
Film Formation ◽  
Sol Gel ◽  
Metal Halide ◽  
Film Morphology ◽  
Metal Halide Perovskite ◽  
Sol Gel Process ◽  
Thin Film Formation ◽  
Halide Perovskite ◽  
Gel Processing

We show that metal halide perovskite thin film formation is a sol–gel process which allows us to improve film morphology, achieving roughness ∼1 nm via process and additive engineering.

Sol-Gel Processing of Lithium Niobate Thin-Layers on Silicon

1988 ◽  
Vol 121 ◽  
Author(s):  
Dennis J. Eichorst ◽  
D. A. Payne
Keyword(s):  
Sol Gel ◽  
Solution Chemistry ◽  
Thin Layers ◽  
Processing Route ◽  
High Quality ◽  
Spin Casting ◽  
Evolution Of Structure ◽  
Stable Solutions ◽  
Gel Processing

ABSTRACTSol-gel processing was used for the fabrication of LiNbO3 thin-layers on semiconductors. Two different alkoxide systems were investigated (i.e., ethoxide vs. methoxyethoxide) to determine the role of solution chemistry on the evolution of structure in LiNbO3 layers. An alcohol exchange reaction, which produced lithium niobium methoxyethoxide, proved advantageous with respect to the amount of hydrolysis water content which could be added to give stable solutions. Spin-casting was used for the deposition of thin-layers which crystallized at 500 C on Si. The refractive index of sol-gel derived LiNbO3 was determined to be similar to sputtered or epitaxially grown films. Data are reported for the processing route and the material characteristics. Methoxyethanol based systems appeared to be more forgiving than ethanol based solutions for the fabrication of high-quality thin-layer devices.

Influence Of Hybridation With A Silicate Network On The Properties Of An Eu 3+ Complex Derived From Dipicolinic Acid

1999 ◽  
Vol 576 ◽  
Author(s):  
A. C. Franville ◽  
D. Zambon ◽  
R. Mahiou ◽  
Y. Troin ◽  
J. C. Cousseins
Keyword(s):  
Organic Molecules ◽  
Dipicolinic Acid ◽  
Sol Gel ◽  
Silicate Network ◽  
Hybrid Gels ◽  
Organic Species ◽  
Covalent Grafting ◽  
Sol Gel Process ◽  
Gel Processing ◽  
The Eu

ABSTRACTIn this paper, the preparation, the characterization and the optical features of organicinorganic materials incorporating a trivalent europium organic chelate into a silicate network are described. The covalent grafting and the sol-gel process allow to obtain monophasic hybrid gels in which the structure and the activity of the organic molecules were retained. The Eu3+ coordination mode is not sensitive to the sol-gel processing conditions whereas the morphology of materials, their thermal resistance and their luminescence properties may be adjusted. Characteristics of hybrid compounds are compared to those of the corresponding organic species.

scholarly journals Characterization of LiCo Nanopowders Produced by Sol-Gel Processing

2010 ◽  
Vol 2010 ◽  
pp. 1-8 ◽  
Author(s):  
Sina Soltanmohammad ◽  
Sirous Asgari
Keyword(s):  
Thermal Analyses ◽  
Sol Gel ◽  
Lithium Ion ◽  
Chelating Agent ◽  
Complexing Agents ◽  
Complexing Agent ◽  
Transmission Electron ◽  
Sol Gel Process ◽  
Size And Morphology ◽  
Gel Processing

LiCo nanopowders, one of the most important cathode materials for lithium-ion batteries, were synthesized via a modified sol-gel process assisted with triethanolamine (TEA) as a complexing agent. The influence of three different chelating agents including acrylic acid, citric acid, and oxalic acid on the size and morphology of particles was investigated. Structure and morphology of the synthesized powders were characterized by thermogravimetric/differential thermal analyses (TG/DTA), X-ray diffraction (XRD), and transmission electron microscopy (TEM). Results indicate that the powder processed with TEA and calcinated at 800 had an excellent hexagonal ordering of -NaFe-type (space group Rm). Also, the other three complexing agents had a decisive influence on the particle size, shape, morphology, and degree of agglomeration of the resulting oxides. Based on the data presented in this work, it is proposed that the optimized size and distribution of LiCo powders may be achieved through sol-gel processing using TEA as a chelating agent.

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