Mercury porosimetry applied to low density xerogels; relation between structure and mechanical propertiesPirard, René ; Heinrichs, Benoît ; et alin Journal of Sol-Gel Science and Technology (1998), 13(1-3), 335-339 Samples of low density xerogels were submitted to mercury porosimetry at pressures up to 200 MPa. These samples show an unusual behavior: they are first crushed by the isostatic mercury pressure without ... [more ▼] Samples of low density xerogels were submitted to mercury porosimetry at pressures up to 200 MPa. These samples show an unusual behavior: they are first crushed by the isostatic mercury pressure without mercury intrusion and are then intruded by the mercury above a certain pressure. This transition allows the easy determination of the one constant found in the buckling model that is used to interpret the crushing part of the mercury porosimetry experiment. The relation between this constant and the structure of the xerogels determined by TEM and nitrogen adsorption is discussed. [less ▲] Detailed reference viewed: 13 (2 ULg) Rheological characterization on the BaTiO3 sol-gel transition; ; et al in Faraday Discussions (1997), 101 Detailed reference viewed: 20 (3 ULg) Synthesis and characterization of monodisperse spherical zirconia particles; ; Pirard, René et alin Journal of Sol-Gel Science and Technology (1997), 8 Detailed reference viewed: 22 (3 ULg) Rheological characterization on the BaTiO3 sol-gel transition; ; Pirard, René et alin Journal of Sol-Gel Science and Technology (1997), 9 Detailed reference viewed: 12 (3 ULg) Mercury porosimetry applied to low density xerogelsPirard, René ; Heinrichs, Benoît ; et alPoster (1997) Detailed reference viewed: 10 (5 ULg) SYNTHESIS OF SIO2-TIO2 XEROGELS BY SOL-GEL PROCESSPirson, Anne-Marie ; ; Marchot, Pierre et alin Journal of Sol-Gel Science and Technology (1995), 4(3), 179-185 A new method to synthesize SiO2-TiO2 gels by sol-gel process has been developed. This technique uses tetraisopropylorthotitanate [Ti(O'Pr)(4)] and tetraethylorthosilicate [TEOS]: they are mixed in the ... [more ▼] A new method to synthesize SiO2-TiO2 gels by sol-gel process has been developed. This technique uses tetraisopropylorthotitanate [Ti(O'Pr)(4)] and tetraethylorthosilicate [TEOS]: they are mixed in the same solvent and then directly hydrolysed. This one-step reaction is possible because of the use of 2-methoxyethanol, a protic polar solvent. This alcohol plays two different specific roles: it acts as a solvent as well as a stabilizer of titanium alkoxide towards the hydrolysis-precipitation reaction. So, by an accurate adjustment of the quantity of methoxyethanol in the mixture, we can control the reactivity of the titanium precursor. Monolithic and transparent xerogels were obtained whatever the composition. Three monolithic SiO2-TiO2 gels containing 20, 50 and 75 mol% of TiO2 were prepared and studied in details. By using the TG-DSC analysis, we can follow the evolution of the loss of water and organic residues. The structural evolution of gels during calcination is characterized by IR spectroscopy and X-Ray diffraction. [less ▲] Detailed reference viewed: 110 (14 ULg) |
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