Search Results - "Donatti, D. A."

Structural characteristics of P123-modified supercritical drying and hydrophobic ambient pressure drying aerogels by Awano, C.M., Donatti, D.A., de Vicente, F.S., Vollet, D.R.

“…Supercritical drying (SCD) and hydrophobic ambient pressure drying (APD) aerogels were prepared from hydrolysis of tetraethoxysilane in solutions of…”
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Effects of poly(vinyl alcohol) additions on the structure of silica xerogels by Awano, C.M., Donatti, D.A., Ibañez Ruiz, A., Vollet, D.R.

“…Poly(vinyl alcohol)/silica hybrid xerogels were prepared from sonohydrolysis of tetraethoxysilane (TEOS) and additions of water-solution of poly(vinyl alcohol)…”
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Structural Characteristics of Silica Sonogels Prepared with Additions of Isopropyl Alcohol by Donatti, D. A, Ibañez Ruiz, A, Kumakawa, M. M, Vollet, D. R

“…Wet silica gels with ∼1.4 × 10-3 mol SiO2/cm3 and ∼92 vol % liquid phase were obtained from sonohydrolysis of tetraethoxysilane (TEOS) with different additions…”
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A SAXS study of kinetics of aggregation of TEOS-derived sonogels at different temperatures by Vollet, D.R., Donatti, D.A., Ibañez Ruiz, A.

“…The kinetics of aggregation of tetraethoxysilane (TEOS)-derived silica sols, produced by acid-catalyzed and ultrasound-stimulated hydrolysis, were studied by…”
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Structural characteristics of gels prepared from sonohydrolysis and conventional hydrolysis of TEOS: an emphasis on the mass fractal as determined from the pore size distribution by Vollet, D. R., Torres, R. R., Donatti, D. A., Ibañez Ruiz, A.

“…Silica gels were preparated from fixed proportion mixtures of tetraethoxysilane, water and hydrocloric acid, using either ultrasound stimulation (US) or…”
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Structural study of composites of aerosil fumed silica and tetraethoxysilane-derived sonogels by Donatti, D.A., Ruiz, A. Ibañez, Vollet, D.R.

“…Composites of aerosil fumed silica and tetraethoxysilane-derived sonogel were prepared by changing the aerosil content between 0 and 30 wt% with respect to the…”
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Structural properties of silica gels prepared from oxalic-acid-catalyzed tetraethoxysilane sonohydrolysis by Donatti, D. A., Ruiz, A. Ibañez, Vicelli, M. R., Vollet, D. R.

“…About ∼2.1 × 10−3 mol SiO2 cm−3 and ∼88%‐volume liquid‐phase silica wet gels were prepared from oxalic‐acid‐catalyzed tetraethoxysilane (TEOS) sonohydrolysis…”
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About the thermal stability and pore elimination in the ordered hexagonal mesoporous silica SBA-15 by da Silveira, T., Awano, C.M., Donatti, D.A., de Vicente, F.S., Vollet, D.R.

“…•Ethanol-washed and vacuum dried SBA-15 was heat treated at several temperatures.•The volume of the ordered hexagonal pores diminishes with temperature.•The…”
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Mass fractal characteristics of silica sonogels as determined by small-angle x-ray scattering and nitrogen adsorption by DONATTI, D. A, VOLLET, D. R, IBANEZ RUIZ, A, MESQUITA, A, SILVA, T. F. P

“…A sample series of silica sonogels was prepared using different water-tetraethoxysilane molar ratio (r{sub w}) in the gelation step of the process in order to…”
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Effect of the temperature on the TMOS sono-hydrolysis and a study of the structure of the resulting aged sonogels by Vollet, D.R., Donatti, D.A., Ibañez Ruiz, A., Maceti, H.

“…The effect of temperature on the oxalic acid catalyzed sono-hydrolysis of tetramethoxysilane (TMOS) was studied by means of a heat flux calorimetric method…”
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From sol to aerogel: a study of the nanostructural characteristics of TEOS derived sonogels by Donatti, D.A, Ibañez Ruiz, A, Vollet, D.R

“…The nanostructural characteristics of acid-catalyzed sonogels are studied along the aging process at 60 °C in saturated conditions and after the CO 2…”
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A study of the hydrolysis pathway in oxalic acid catalyzed reacting TMOS-water mixtures under ultrasound stimulation by DONATTI, D. A, VOLLET, D. R, IBANEZ RUIZ, A

“…The hydrolysis of TMOS in oxalic acid catalyzed reacting TMOS-water mixtures, under ultrasound stimulation, was studied by fitting a simplified dissolution and…”
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Structural Modifications in Silica Sonogels Prepared with Additions of Poly(vinyl alcohol) by Portella, J. A, Donatti, D. A, Ibañez Ruiz, A, Vollet, D. R

“…Silica wet gels were prepared from acid sonohydrolysis of tetraethoxysilane (TEOS) and additions of poly(vinyl alcohol) (PVA)−water solution. Aerogels were…”
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Hydrolysis rates of TMOS catalyzed by oxalic acid and stimulated by ultrasound by VOLLET, D. R, DONATTI, D. A, IBANEZ RUIZ, A

“…A simple calorimetric method was employed to study the kinetics of the hydrolysis of the solventless TMOS-water mixtures, under ultrasound stimulation, as a…”
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Spectroscopic and thermal characterization in poly( p-phenylene vinylene)/sol–gel silica sample by Pilla, V., Andrade, A.A., Lima, S.M., Catunda, T., Donatti, D.A., Vollet, D.R., Ruiz, A.I.

“…The absorption and luminescence spectra for the poly( p-phenylene vinylene)/sol–gel silica with different thermal treatments were measured. A considerable…”
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Structural characteristics of silica sonogels prepared with different proportions of TEOS and TMOS by Vollet, D.R., Nunes, L.M., Donatti, D.A., Ibañez Ruiz, A., Maceti, H.

“…Sonohydrolysis of mixtures of tetraethoxysilane (TEOS) and tetramethoxysilane (TMOS) with different TMOS/(TMOS + TEOS) molar ratio R was carried out to obtain…”
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Running holograms in azopolymer films by Freschi, A. A., de Vicente, F. S., Mello, T. B., Donatti, D. A., Vollet, D. R.

“…We report investigations on running holograms recorded in an azopolymer film made of a poly(methyl methacrylate) matrix doped with Disperse Red 1. Two-wave…”
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Mass fractal characteristics of sonogels prepared from sonohydrolysis of tetraethoxysilane with additions of dimethylformamide by Vollet, D.R., de Sousa, W.A.T., Donatti, D.A., Ibañez Ruiz, A.

“…Wet silica gels with ∼1.4 × 10 −3 mol SiO 2/cm 3 and ∼90 vol.% liquid phase were prepared from the sonohydrolysis of tetraethoxysilane (TEOS) with different…”
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Effects of the water quantity on the solventless TEOS hydrolysis under ultrasound stimulation by DONATTI, D. A, VOLLET, D. R

“…The acid hydrolysis under ultrasound stimulation of solventless tetraethoxysilane(TEOS)-water mixtures was studied at 40°C, by means of a heat flux…”
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A calorimetric study of the ultrasound-stimulated hydrolysis of solventless TEOS-water mixtures by Donatti, D. A., Vollet, D. R.

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