SandraDire,*a EvaPagani,aFlorenceBabonneau,b RiccardoCeccatoaandGiovanniCarturana
a Dipartimento di IngegneriadeiMateriali,UniversitadiTrento,v.Mesiano77,38050Trento,Italy
‘
ChimiedelaMatiereCondensee,Universite PierreetMarieCurie/CNRS,4,placeJussieu,Paris,France
Tetraethoxysilane (TEOS) and methyltriethoxysilane (MTES) have been used to preparehybrid SiO2-based membranes. These self-supported materials were obtained from controlled polymerization reactions for various TEOS/MTES molar ratio sensuring the achievemen to fcrack-free disks 8 cm in diameter and 1040 mm in thickness.Therheological behaviour of precursor solutions was studied and gelling times were determined. The whole process, from starting solution to xerogel, was followed by FTIR spectroscopy, viscosity measurements and multi nuclears olid-state NMR, an disdiscussed in terms of the hydrolysis condensation kinetic softetrafunctionalandtrifunctionalsiliconalkoxides.Density,shrinkage,elasticmodulus(E),modulusofrupture(MOR)
andelongationatbreakwerealldeterminedandrelatedtopreferentialstructuralarrangementsofnetworksaccordingtothe
TEOS/MTESratio.
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a Dipartimento di IngegneriadeiMateriali,UniversitadiTrento,v.Mesiano77,38050Trento,Italy
‘
ChimiedelaMatiereCondensee,Universite PierreetMarieCurie/CNRS,4,placeJussieu,Paris,France
Tetraethoxysilane (TEOS) and methyltriethoxysilane (MTES) have been used to preparehybrid SiO2-based membranes. These self-supported materials were obtained from controlled polymerization reactions for various TEOS/MTES molar ratio sensuring the achievemen to fcrack-free disks 8 cm in diameter and 1040 mm in thickness.Therheological behaviour of precursor solutions was studied and gelling times were determined. The whole process, from starting solution to xerogel, was followed by FTIR spectroscopy, viscosity measurements and multi nuclears olid-state NMR, an disdiscussed in terms of the hydrolysis condensation kinetic softetrafunctionalandtrifunctionalsiliconalkoxides.Density,shrinkage,elasticmodulus(E),modulusofrupture(MOR)
andelongationatbreakwerealldeterminedandrelatedtopreferentialstructuralarrangementsofnetworksaccordingtothe
TEOS/MTESratio.
download full text
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