[en] Time-resolved small-angle X-ray scattering (SAXS) measurements performed during the formation of tetraethyl orthosilicate (TEOS) based silica gels in alcohol with 3-(2-aminoethylamino)propyltrimethoxysilane (EDAS) as an additive are reported. The measurements reveal no discontinuity of the nanostructure at the gel point. A chemically induced spinodal phase separation is found to give a coherent picture of the collected data. Increasing the amount of EDAS induces the phase separation on a smaller length scale, which finally leads to a modified gel morphology. The SAXS measurements and the electron micrographs associated with the dry gels could be interpreted in terms of the suggested wet gel formation mechanism.
Disciplines :
Physics Chemistry
Author, co-author :
Gommes, Cédric ; Université de Liège - ULiège > Département de chimie appliquée > Génie chimique - Génie catalytique
Blacher, Silvia ; Université de Liège - ULiège > Département des sciences cliniques > Labo de biologie des tumeurs et du développement
Goderis, Bart; Katholieke Universiteit Leuven - KUL
Pirard, René ; Université de Liège - ULiège > Département de chimie appliquée > Génie chimique - Génie catalytique
Heinrichs, Benoît ; Université de Liège - ULiège > Département de chimie appliquée > Génie chimique - Génie catalytique
Alié, Christelle ; Université de Liège - ULiège > Chimie générale et chimie physique
Pirard, Jean-Paul ; Université de Liège - ULiège > Département de chimie appliquée > Génie chimique - Génie catalytique
Language :
English
Title :
In situ SAXS analysis of silica gel formation with an additive
Publication date :
01 July 2004
Journal title :
Journal of Physical Chemistry B
ISSN :
1520-6106
eISSN :
1520-5207
Publisher :
Amer Chemical Soc, Washington, United States - Washington
Volume :
108
Issue :
26
Pages :
8983-8991
Peer reviewed :
Peer Reviewed verified by ORBi
Funders :
F.R.S.-FNRS - Fonds de la Recherche Scientifique [BE]
Lenza, R. F. S.; Vasconcelos, W. L. J. Non-Cryst. Solids 2003, 330, 216.
Glatter, O.; Kratky, O. Small-angle X-ray Scattering; Academic Press: New York, 1982.
Schmidt, P. W. Some Fundamental Concepts and Techniques Useful in Small-Angle Scattering Studies of Disordered Solids. In. Modern Aspects of Small Angle Scattering; Brumberger. H., Ed.; Kluwer Academic Publishers: Dordrecht. 1995; p 1.
Mortensen, K. Structural studies of polymer systems using small-angle neutron scattering. In Advanced Functional Molecules and polymers: Nalwa, H. S., Ed.; Overseas Publishers Association: Amsterdam, 2001; p 223.
Teixeira, J. J. Appl. Crystallogr. 1988, 21, 781.
Mortensen, K.; Pedersen, J. K. Macromolecules 1993, 26, 805.
Kaneko, K. J. Membr. Sci. 1994, 96, 59.
Dietler, G.; Aubert, C.; Cannel, D. S.; Wiltzius, P. Phys. Rev. Lett. 1986, 57, 3117.
Martin, J. E.; Keefer, K. D. Phys. Rev. A 1986, 34, 4988.
Carpineti, M.; Giglio M.; Degiorgio, V. Phys. Rev. E 1995, 51, 590.
Hasmy, A.; Jullien, R. J. Non-Cryst. Solids 1995, 156, 342.
Guenoun, P.; Gastaud, R.; Perrot, F.; Beysens, D. Phys. Rev. A 1987, 36, 4876.
de Gennes, P.-G. J. Phys. Lett. 1979, 40, 69.
Stanley, H. E. Introduction to phase transitions and critical phenomena; Clarendon Press: Oxford, 1971.
Schaefer, D. W.; Bunker, B. C.; Wilcoxon, J. P. Proc. R. Soc. London, A 1989, 423, 35.
Vonk, C. G. J. Appl. Crystallogr. 1973, 6, 81.
Siggia, E. D. Phys. Rev. A 1979, 20, 595.
Onuki, A.; Puri, S. Phys. Rev. E 1999, 59, 1331.
Ma, H. S.; Roberts, A. P.; Prévost, J. H.; Jullien, R.; Scherer, G. W. J. Non-Cryst. Solids 2000, 277, 127.
