In situ X-ray measurements to probe a new solid-state polycondensation mechanism for the design of supramolecular organo-bridged silsesquioxanes.
A long-range ordered organic/inorganic material is synthesized from a bis-silane, (EtO)(3)Si-(CH(2))(3)-NHCONH-C(6)H(4)-NHCONH-(CH(2))(3)-Si(OEt)(3). This crosslinked sol-gel solid exhibits a supramolecular organization via intermolecular hydrogen bonding interactions between urea groups (-NHCONH-) and covalent siloxane bonding, triple bond Si-O-Si triple bond. Time-resolved in situ X-ray measurements (coupling small- and wide-angle X-ray scattering techniques) are performed to follow the different steps involved in the synthetic process. A new mechanism based on the crystallization of the hydrolyzed species followed by their polycondensation in solid state is proposed.
Dieudonné
Philippe
P
Laboratoire des Colloïdes, Verres et Nanomatériaux, UMR CNRS 5587, Université Montpellier 2, 34095 Montpellier Cedex 5, France. dieudonn@lcvn.univ-montp2.fr
Man
Michel Wong Chi
MW
Pichon
Benoît P
BP
Vellutini
Luc
L
Bantignies
Jean-Louis
JL
Blanc
Christophe
C
Creff
Gaëlle
G
Finet
Stéphanie
S
Sauvajol
Jean-Louis
JL
Bied
Catherine
C
Moreau
Joël J E
JJ
D008958:Models, Molecular; D012542:Scattering, Radiation; D012833:Siloxanes / Q000737:chemistry*; D014961:X-Ray Diffraction / Q000379:methods*
D012833:Siloxanes