Results 261 to 270 of about 154,019 (297)

Sintering of α-Al2O3—Amorphous silica compacts

Ceramics International, 1982
Sintering of α-Al2O3—fused SiO2 compacts at temperatures of 1350–1500 °C is affected by metastable and stable phase reactions. Shrinkage maxima in the range 10 to 30 mole % Al2O3 are the result of cristobalite in the fused SiO2 and its reaction with α-Al2O3 to form the eutectic of the metastable phase equilibrium diagram for SiO2 (cristobalite)—α-Al2O3
Y. Nurishi, J.A. Pask
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Hydrophobicity of Hydroxylated Amorphous Fused Silica Surfaces

Langmuir, 2013
Understanding the mechanism of water adsorption on silica is important in many fields of science and technology, such as geo- and atmospheric chemistry. Vibrational IR-visible sum-frequency generation (SFG) spectroscopy of hydroxyls (~3100-3800 cm(-1)) at the amorphous SiO2 surface in contact with air of varying relative humidity provides information ...
Oleksandr, Isaienko, Eric, Borguet
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Thorium sorption on amorphous silica

Geochimica et Cosmochimica Acta, 1995
Abstract The sorption of Th on amorphous colloidal particles of Si0 2 (Aerosil OX 200) has been studied in perchlorate media in order to obtain quantitative information on the sorption of The on silica. In order to quantify the pH dependence of the charge of the silica surface, potentiometric surface titrations of the silica particles have also been
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Characterization of amorphous silica surface

Reaction Kinetics & Catalysis Letters, 1993
A short survey is presented of results on the dehydration, dehydroxylation and rehydroxylation of the surface of amorphous silica.
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Stability of amorphous indomethacin compounded with silica

International Journal of Pharmaceutics, 2001
The stability of indomethacin (IM) compounded with SiO(2) either by co-grinding or by melt-quenching was examined by recrystallization kinetics under the conditions 30 degrees C and 11% relative humidity. A decrease of the recrystallization rate with and without an appreciable induction period was observed in both compounds.
T, Watanabe, N, Wakiyama, F, Usui, M, Ikeda, T, Isobe, M, Senna   +5 more
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Amorphous non-nano silica spheres

2022
Disclosed herein are methods of deriving silica from biological materials, compositions of such matter, articles of manufacture and amorphous silica spheres. Evidence demonstrates what is disclosed herein to be superior to the silica obtained from sand and other non-renewable sources of silica in personal care products, particularly cosmetics.
Pintado, Manuela E., Madureira, Ana Raquel, Costa, Joana Ribeiro, Dale, Morrison, Dale, Alexander, Dale, Rhys, Huang, Yong   +6 more
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Toxicity of Silica Nanomaterials: Zeolites, Mesoporous Silica, and Amorphous Silica Nanoparticles

2010
Publisher Summary In this chapter, an overview of the toxicity of silica-based nanomaterials is presented. Porous materials, such as crystalline, microporous zeolites, and mesoporous silica materials, have two nanoscale aspects: nanoscale pores that provide large internal surface areas and nanoscale crystal or particle sizes that may lead to unique ...
Anton Petushkov, Nicholas Ndiege, Aliasger K. Salem, Sarah C. Larsen   +3 more
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Shrinkage of Amorphous Silica Fibers

2008
By the application of a new technique, the viscosity of amorphous silica fibers was determined in the 1100-1350 C temperature range. An equation was derived that describes the kinetics of shrinkage of the fibers in terms of their radius, viscosity, and surface tension.
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Hypertension due to inhaled submicron amorphous silica

Toxicology and Applied Pharmacology, 1959
Abstract 1. 1. An inhalation study with synthetic amorphous silica of 200 A particle size range provoked elevation of right and left ventricular pressures in rabbits. 2. 2. The magnitude of the cardiac response was proportional to the dose of SiO 2 administered, the rate of exposure, and the duration of dust inhalation. 3. 3.
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AMORPHOUS SILICAS AND ORAL COMPOSITIONS

1997
An amorphous silica having an RDA value of between 30 and 70, an oil absorption capacity of between 100 and 155cc/100g and a moisture loss of less than 7 % w/w, can be incorporated at a 10 % to 25 % loading into a transparent toothpaste having a refractive index of above 1.445, this toothpaste having an RDA value of between 30 and 60.
CROSFIELD JOSEPH & SONS, STANIER PETER WILLIAM   +1 more
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