title: Insights into the self-directed structuring of hybrid organic-inorganic silicas through infrared studies.
abstract: Fourier transform infrared (FTIR) spectroscopy has been used to probe the organization of the organic fragments in lamellar bridged silsesquioxanes with organic substructures based on alkylene chains of various lengths and urea groups [O1.5Si(CH2)3NHCONH(CH2)nNHCONH(CH2)3SiO1.5] (n = 6, 8-12). The structure and intermolecular interactions (hydrophobic and H-bonding) of these well-defined self-structured hybrid silicas are discussed in relation to their powder X-ray diffraction patterns. The degree of structural order is determined by the length and parity of the alkylene spacer. A concomitant enhancement in the degree of condensation of the inorganic component and a decrease in the strength of the hydrophobic interactions between the organic components are demonstrated. The strength and directionality of the H-bonding are directly correlated to the crystalllinity of the organic-inorganic hybrid materials.
authors.affiliation: Laboratoire des Colloïdes, Verres et Nanomatériaux (UMR CNRS 5587), Université Montpellier II, 34095 Montpellier Cedex 5, France. jean-louis.bantinies@lcvn.univ-Montp2.fr
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Bantignies
authors.forename: Luc
authors.initials: L
authors.lastname: Vellutini
authors.forename: David
authors.initials: D
authors.lastname: Maurin
authors.forename: Patrick
authors.initials: P
authors.lastname: Hermet
authors.forename: Philippe
authors.initials: P
authors.lastname: Dieudonné
authors.forename: Michel
authors.initials: M
authors.lastname: Wong Chi Man
authors.forename: John R
authors.initials: JR
authors.lastname: Bartlett
authors.forename: Catherine
authors.initials: C
authors.lastname: Bied
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Sauvajol
authors.forename: Joël J E
authors.initials: JJ
authors.lastname: Moreau
mesh_terms: D006860:Hydrogen Bonding; D008958:Models, Molecular; D015394:Molecular Structure; D017646:Organosilicon Compounds / Q000737:chemistry*; D012680:Sensitivity and Specificity; D012822:Silicon Dioxide / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods; D014961:X-Ray Diffraction
chemical_list: D017646:Organosilicon Compounds; D012822:Silicon Dioxide