Proton Conductivity of Amorphous Hydrated Zirconia-Yttria Solid Solutions

2007 ◽  
Vol 336-338 ◽  
pp. 391-394
Author(s):  
Gianfranco Dell'Agli ◽  
Giuseppe Mascolo ◽  
Maria Cristina Mascolo ◽  
Concetta Pagliuca ◽  
Paolo Perna ◽  
...  
Keyword(s):  
Surface Area ◽  
Proton Conductivity ◽  
Solid Solutions ◽  
Amorphous Solid ◽  
Impedance Method ◽  
Starting Mixture ◽  
Variable Content ◽  
Mechanical Mixtures ◽  
Y2o3 Content ◽  
Hydrated Zirconia

Mechanical mixtures of zirconia xerogel with variable content of crystalline Y2O3 up to 25 mol%, were hydrothermally treated by microwave route at 110 °C for 2 hours in the presence of 0.2 M solution of (KOH+K2CO3) mineralizer. The resulting amorphous hydrated zirconia-yttria solid solutions with a maximum solubility of Y2O3 content between 20 ~ 25 mol%, showed a remarkable reduction of the surface area at the increasing Y2O3 content of the starting mixture. The as-synthesized products and the corresponding calcined powders at 400 °C were uniaxially pressed into pellets (10 x 7 x 2 ~ 4 mm, in width) at 150 MPa. Conductivities were measured at 25 °C by AC impedance method with a frequency range from 10 Hz to 1 MHz with the pellets equilibrated either under silica gel or under increasing relative humidity (RH) up to ~90 %. The effects of composition, surface area, calcination temperature and relative RH on the proton conductivity of the amorphous solid solutions are discussed.

Proton Conductivity of Amorphous Hydrated Zirconia-Yttria Solid Solutions

2007 ◽  
pp. 391-394
Author(s):  
Gianfranco Dell'Agli ◽  
Giuseppe Mascolo ◽  
Maria Cristina Mascolo ◽  
Concetta Pagliuca ◽  
Paolo Perna ◽  
...  
Keyword(s):  
Proton Conductivity ◽  
Solid Solutions ◽  
Hydrated Zirconia

Porous Al2O3/Al catalyst supports fabricated by an Al(OH)3/Al mixture and the effect of agglomerates

2005 ◽  
Vol 20 (3) ◽  
pp. 672-679 ◽  
Author(s):  
Zhen-Yan Deng ◽  
Yoshihisa Tanaka ◽  
Yoshio Sakka ◽  
Yutaka Kagawa
Keyword(s):  
Surface Area ◽  
Compaction Pressure ◽  
High Surface ◽  
High Surface Area ◽  
Catalyst Supports ◽  
Al Content ◽  
Starting Mixture ◽  
Mechanical And Electrical Properties ◽  
Uniform Microstructure ◽  
Compact Density

Porous Al2O3/Al catalyst supports were fabricated using a mixture of Al(OH)3 and Al powders, followed by pressureless sintering at a temperature of 600 °C in vacuum. Different pressures were used to prepare green compacts. High compaction pressure led to a high surface area and good mechanical and electrical properties for the sintered specimens. However, when the Al content in the sintered specimen exceeded a definite value, high compaction pressure decreased the surface area abruptly. Scanning electron microscopy observations revealed that agglomeration in the starting mixture has a significant effect on the microstructure of the sintered specimens. High compaction pressure greatly eliminated the agglomerates and led to a uniform microstructure for the sintered specimens. However, when the Al content in the starting mixture was too high, Al particles in the compacts prepared by the high pressure were largely sintered due to the high compact density so that most of the pores were closed. The present study indicates that a suitable compaction pressure is critical to obtaining superior Al2O3/Al supports.

Synthesis of ZrO2–Y6WO12 solid solution powders by a polymerized complex method

1998 ◽  
Vol 13 (4) ◽  
pp. 939-943 ◽  
Author(s):  
Junfeng Ma ◽  
Masahiro Yoshimura ◽  
Masato Kakihana ◽  
Masatomo Yashima
Keyword(s):  
Solid Solution ◽  
Crystallite Size ◽  
Surface Area ◽  
Solid Solutions ◽  
Lattice Parameter ◽  
Cubic Phase ◽  
Complex Method ◽  
Amorphous Precursor ◽  
Fine Powders ◽  
Polymerized Complex Method

A series of solid solutions (1 − x) ZrO2 · xY0.857 W0.143 O1.714 (1/7Y6WO12) of metastable cubic phase were synthesized at 800 °C through a polymerized complex method. Lattice parameter a0 of solid solutions varies linearly with Y0.857 W0.143 O1.714 content (x). Crystallization began to occur above 400 °C from amorphous precursor to yield at 800 °C fine powders of 6–10 nm and 19–40 m2/g for crystallite size and surface area, respectively.

Structure evolution, ionic and proton conductivity of solid solutions based on Nd2Hf2O7

2020 ◽  
Vol 46 (11) ◽  
pp. 17383-17391 ◽  
Author(s):  
A.V. Shlyakhtina ◽  
N.V. Lyskov ◽  
A.N. Shchegolikhin ◽  
S.A. Chernyak ◽  
A.V. Knotko ◽  
...  
Keyword(s):  
Proton Conductivity ◽  
Solid Solutions ◽  
Structure Evolution

Proton conductivity of Ba2(In1–x Al x )2O5 solid solutions

2015 ◽  
Vol 51 (9) ◽  
pp. 877-880 ◽  
Author(s):  
N. A. Kochetova ◽  
I. V. Alyabysheva ◽  
I. E. Animitsa
Keyword(s):  
Proton Conductivity ◽  
Solid Solutions

Enthalpy of formation and thermodynamic insights into yttrium doped BaZrO3

2014 ◽  
Vol 2 (42) ◽  
pp. 17840-17847 ◽  
Author(s):  
M. D. Gonçalves ◽  
P. S. Maram ◽  
R. Muccillo ◽  
A. Navrotsky
Keyword(s):  
Enthalpy Of Formation ◽  
Proton Conductivity ◽  
Solid Solutions ◽  
Thermodynamic Data ◽  
Defect Chemistry ◽  
Enthalpies Of Formation ◽  
Materials Selection

This work brings insights into the defect chemistry of YBZ solid solutions by measuring enthalpies of formation. We find a correlation between the obtained thermodynamic data and the known trend of the proton conductivity of YBZ solid solutions. This study is important for informed thermodynamic history-based materials selection and processing for specific applications.

Rubber Resins: Some Properties and Possibilities of Use

1944 ◽  
Vol 17 (3) ◽  
pp. 731-737
Author(s):  
Charles F. Mason
Keyword(s):  
Calcium Carbonate ◽  
Solid Solutions ◽  
Raw Material ◽  
Gutta Percha ◽  
Sulfur Chloride ◽  
Mechanical Mixtures ◽  
Electric Cables

Abstract However, their present uses and possible future uses deserve consideration. Their tendency to thicken in certain solvents has been applied to use in imparting false body (thickening) to certain varnishes. In such cases it is likely that the rubber resin is modified to reduce tackiness before compounding it into quick-drying spirit varnishes. As plasticizers for brittle resins and asphalts they afford a very inexpensive raw material. But, again, experiments must be performed to see if the rubber resin is compatible with the natural or synthetic one, as there is little information as to whether plasticizers form solid solutions or only mechanical mixtures with the resins after heating and mixing. In one case a large shoe manufacturer purchased many tons of gutta-percha resin for impregnation of threads used in sewing on soles; the object was to prevent the entrance of moisture into the shoe and to supply a flexible adhesive. Electric friction tape, which must have an eversoft tacky surface, is coated with a compound of a bitumen, regenerated rubber, and a gutta resin, and is similar in composition to readily appliable insulation pastes, which are used on underground electric cables. The use in ever-soft adhesives and in flypaper are only two of the minor ones. The application of these resins to textiles in the form of emulsions shows large possibilities, as they can be emulsified with ammonium oleate or linoleate and, on drying, leave behind films of rubber resin and the fat acid of the emulsifier. A hardened balata resin has been used in linoleum cement. The soft resin or even the oily one can be hardened by heating for four hours at 80° C, after adding 1 per cent of manganese resinate or 0.5 per cent of calcium carbonate. Treatment of the same resin with sulfur chloride results in a viscous resin which, when warm, can be pulled out into ropes like taffy candy and, when cold, is still viscous. In closing, the writer wishes to state that, even if a reader may fail to find here the exact information he desires about a certain rubber resin, let it be hoped that what information he does find will save many hours of fruitless toil.

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