Results 151 to 160 of about 1,886 (171)

CdS semiconductor doped silica xerogels

Materials Science and Engineering: A, 1993
Abstract CdS doped amorphous silica was prepared by the sol-gel method. The CdS concentration in weight varied from 5% to 20%. The samples were characterized by four different and complementary techniques: X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM), low frequency inelastic Raman scattering (LOFIRS) and small ...
A. Othmani, C. Bovier, J.C. Plenet, J. Dumas, B. Champagnon, C. Mai   +5 more
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Elastic Properties of Silica Xerogels

Journal of the American Ceramic Society, 1990
To calculate elastic constants, longitudinal and tranverse acoustic wave velocities were measured for silica xerogels as a function of relative humidity (rh). The silica xerogels studied are microporous with open porosity of 53 vol%. The longitudinal wave velocity exhibits a minimum at about 35% rh.
Lisa C. Klein, Bennet Abramoff
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Tunable dye-doped xerogel lasers

Conference on Lasers and Electro-Optics Europe, 1994
The easiest route to produce tunable optical pulses is to use a broadband fluorescent gain medium. For this purpose organic dye molecules are very suitable and have been widely used in solution during the past 30 years. Today, new crystals such as titanium sapphire, and nonlinear techniques such as optical parametric oscillation, may provide solid ...
M. Canva, P. Georges, A. Dubois, A. Brun, F. Chaput, J.-P. Boilot   +5 more
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Structural characterization of silica xerogels

Journal of Non-Crystalline Solids, 1995
The structure of silica xerogels prepared following a fully inorganic route was investigated by means of the concurrent use of gas-adsorption, solid-state nuclear magnetic resonance and neutron diffraction techniques. Such an approach enables consistent estimates for the particle and pore sizes to be derived which show the existence of microporous ...
M.J. Muñoz-Aguado, M. Gregorkiewitz, F.J. Bermejo   +2 more
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Thermal stability of xerogel films

Thin Solid Films, 2001
In this work, we have investigated the thermal stability of the organic component of porous SiO2 (xerogel) films using a combination of ion beam techniques and thermal desorption spectroscopy (TDS). Ion beam techniques reveal a large concentration of carbon and hydrogen atoms in this film.
A. Kumar, H. Bakhru, J.B. Fortin, G.-R. Yang, T.-M. Lu, C. Jin, W.W. Lee   +6 more
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Mechanical Properties of Silica Xerogels

Journal of the American Ceramic Society, 1991
Strengths have been measured for silica xerogels using four‐point bending. The silica xerogels studied are microporous with open porosity of 53 vol%. Strengths were measured on fresh samples, samples which had been outgassed at 250°C, samples which were exposed to ambient conditions for 2 d, and samples stored in ethanol.
Bennett Abramoff, Lisa C. Klein
openaire   +1 more source

Defects in nanocrystalline ceria xerogel

2011
Nanocrystalline ceria was produced via sol-gel from Ce alkoxides with and without the addition of water and a chelating agent (acetylacetone). Microstructure analysis of the resulting powder was conducted on laboratory and synchrotron radiation data using the Whole Powder Pattern Modelling algorithm.
Mueller, Melanie, Leoni, Matteo, Di Maggio, Rosa, Scardi, Paolo   +3 more
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Xerogel package

Chemometrics and Intelligent Laboratory Systems, 2009
Rameela Chandrasekhar, Jeffrey C. Miecznikowski, Daniel P. Gaile, Venu Govindaraju, Frank V. Bright, Kimberly F. Sellers   +5 more
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Microstructure of puffed silica xerogel

Journal of Materials Science Letters, 1993
The structural evolution that takes place during sol-to-gel and gel-to-glass transformations has fascinated both experimentalists and theoreticians [1-5]. In situ techniques [6] such as nuclear magnetic resonance, Raman and infrared spectroscopy, small-angle X-ray, neutron and light scattering, and studies including gas adsorption-desorption analyses ...
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Fluorescent chemosensing silica xerogels

High Energy Chemistry, 2014
M. S. Pilipenko, A. V. Koshkin, V. A. Sazhnikov, M. V. Alfimov   +3 more
openaire   +1 more source