Porous properties of coprecipitated Al2O3-SiO2 xerogels prepared from aluminium nitrate nonahydrate and tetraethylorthosilicate

1999 ◽  
Vol 9 (6) ◽  
pp. 1307-1312 ◽  
Author(s):  
Kiyoshi Okada ◽  
Takahiro Tomita ◽  
Yoshikazu Kameshima ◽  
Atsuo Yasumori ◽  
Kenneth J. D. MacKenzie
Keyword(s):  
Aluminium Nitrate ◽  
Porous Properties ◽  
Nitrate Nonahydrate ◽  
Aluminium Nitrate Nonahydrate

Comparative Aluminium Mobilizing Actions of Several Chelators in Aluminium-Loaded Uraemic Rats

1994 ◽  
Vol 13 (2) ◽  
pp. 135-139 ◽  
Author(s):  
M. Gómez ◽  
J.L. Domingo ◽  
D. del Castillo ◽  
J.M. Llobet ◽  
J. Corbella
Keyword(s):  
Citric Acid ◽  
Succinic Acid ◽  
Acid Treatment ◽  
Relative Effectiveness ◽  
Aluminium Nitrate ◽  
Safety Margins ◽  
Daily Dose ◽  
Nitrate Nonahydrate ◽  
Aluminium Nitrate Nonahydrate

The relative effectiveness of deferoxamine (DFO), 1,2-dimethyl-1,3-hydroxypyrid-4-one (L1), and citric and succinic acids in mobilizing and promoting excretion of aluminium (Al) were compared in female uraemic rats which had previously received aluminium nitrate nonahydrate i.p. in a daily dose of 45 mg kg-1 for 3 weeks (5 days/week). Chelators were administered s.c. at doses equal to one-eighth of their respective LD50 for five days. L1 was also given p.o. in doses of 200 mg kg-1 day-1. Total urines were collected 24 h after each chelator administration. Total urinary Al excreted over the 5-day period, expressed as mg kg-1, were: controls, 3.4; DFO-treated, 4.5 (P<0.05); citric acid-treated, 3.7; and succinic acid-treated, 2.7. Although the daily amounts of Al excreted into urine by L1-treated rats were significantly higher ( P<0.001) than those of the controls, most animals died during the period of treatment. Measurements of Al in selected tissues 24 h after the last administration of each chelator revealed that none of the compounds significantly altered the Al concentration in bone, kidney, and brain, whereas only DFO and succinic acid significantly reduced the levels of Al in spleen. Moreover, L1 (given s.c. or p.o.) and citric acid treatment led to a significant reduction in the liver Al burden. These results indicate the need for further investigations to determine the toxicity and the therapeutical safety margins of L1.

Surface Acidity and Hydrophilicity of Coprecipitated Al2O3–SiO2 Xerogels Prepared from Aluminium Nitrate Nonahydrate and Tetraethylorthosilicate

1999 ◽  
Vol 219 (1) ◽  
pp. 195-200 ◽  
Author(s):  
Kiyoshi Okada ◽  
Takahiro Tomita ◽  
Yoshikazu Kameshima ◽  
Atsuo Yasumori ◽  
Kenneth J.D. MacKenzie
Keyword(s):  
Surface Acidity ◽  
Aluminium Nitrate ◽  
Nitrate Nonahydrate ◽  
Aluminium Nitrate Nonahydrate

scholarly journals Synthesis of highly porous Al2O3-YAG composite ceramics

2016 ◽  
Vol 48 (3) ◽  
pp. 303-315
Author(s):  
Adela Egelja ◽  
Jelena Majstorovic ◽  
Nikola Vukovic ◽  
Miroslav Stankovic ◽  
Dusan Bucevac
Keyword(s):  
Sintering Temperature ◽  
Water Solution ◽  
Nitrate Hexahydrate ◽  
Yttrium Nitrate ◽  
Aluminium Nitrate ◽  
Composite Ceramics ◽  
X Ray ◽  
Highly Porous ◽  
Yttrium Nitrate Hexahydrate ◽  
Aluminium Nitrate Nonahydrate

Al2O3-YAG composite was obtained by sintering of porous Al2O3 preforms infiltrated with water solution of aluminium nitrate nonahydrate, Al(NO3)3?9H2O and yttrium nitrate hexahydrate, Y(NO3)3?6H2O. Al2O3 preforms with porosity varying from 26 to 50% were obtained after sintering at temperature ranging from 1100 to 1500?C. Sintering of the infiltrated Al2O3 preforms led to formation of YAG particles due to reaction between Y2O3 and Al2O3 at high temperature. It was found that variation of porosity of alumina preforms and sintering temperature is an effective way to fabricate Al2O3-YAG composite with an unusual combination of properties. Open porosity was in the range 15-35%, specific surface was 0.6-6.1 m2/g, pore size was 150-900 nm whereas compressive strength was from 50 to 250 MPa. The effect of sintering temperature on YAG formation and phase composition were investigated using X-ray diffractometry whereas microstructure of the composite was analysed by scanning electron microscopy.

Structures of chemically stabilized ceramics

1993 ◽  
Vol 51 ◽  
pp. 924-925
Author(s):  
Pratibha L. Gai ◽  
M. A. Saltzberg ◽  
L.G. Hanna ◽  
S.C. Winchester
Keyword(s):  
High Temperature ◽  
Calcium Nitrate ◽  
Nitrate Hexahydrate ◽  
Chemical Route ◽  
Cubic Form ◽  
Tetragonal Form ◽  
Wet Chemical ◽  
Wet Chemical Route ◽  
Final Composition ◽  
Aluminium Nitrate Nonahydrate

Silica based ceramics are some of the most fundamental in crystal chemistry. The cristobalite form of silica has two modifications, α (low temperature, tetragonal form) and β (high temperature, cubic form). This paper describes our structural studies of unusual chemically stabilized cristobalite (CSC) material, a room temperature silica-based ceramic containing small amounts of dopants, prepared by a wet chemical route. It displays many of the structural charatcteristics of the high temperature β-cristobalite (∼270°C), but does not undergo phase inversion to α-cristobalite upon cooling. The Structure of α-cristobalite is well established, but that of β is not yet fully understood.Compositions with varying Ca/Al ratio and substitutions in cristobalite were prepared in the series, CaO:Al2O3:SiO2 : 3-x: x : 40, with x= 0-3. For CSC, a clear sol was prepared from Du Pont colloidal silica, Ludox AS-40®, aluminium nitrate nonahydrate, and calcium nitrate hexahydrate in proportions to form a final composition 1:2:40 composition.

Research on Porous Properties of Air-Entrained Lightweight Aggregate Concrete

2013 ◽  
Vol 652-654 ◽  
pp. 1209-1212
Author(s):  
Wei Xin Hu ◽  
Abulitipu. Abudula
Keyword(s):  
Thermal Conductivity ◽  
Porous Structure ◽  
Concrete Strength ◽  
Lightweight Aggregate ◽  
Lightweight Aggregate Concrete ◽  
Aggregate Concrete ◽  
Materials Properties ◽  
Porous Properties ◽  
Concrete Materials ◽  
The Right

Lightweight aggregate concrete with bleed air : the air-entraining agent added to the lightweight aggregate concrete , cement paste to form the porous structure of the porous structure of the right amount of artificial lightweight aggregate concrete . Reduce the density of the concrete to improve the insulation properties of the concrete . Applied to structural insulation concrete strength than 20Mpa, the thermal conductivity is less than 0.36W / ( m • K) . Of lightweight aggregate structure insulation concrete materials properties and microstructure of variation with air entraining agent .

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