Browsing by Author "Moreau, JJE"

Now showing 1 - 2 of 2
  • No Thumbnail Available
    Item
    Nanostructuring of hybrid silicas through a self-recognition process
    (Wiley-VCH Verlag Berlin, 2009-05-11) Arrachart, G; Creff, G; Wadepohl, H; Blanc, C; Bonhomme, C; Babonneau, F; Alonso, B; Bantignies, JL; Carcel, C; Moreau, JJE; Dieudonné, P; Sauvajol, JL; Massiot, D; Man, MWC
    The hydrolysis and condensation of a silylated derivative of ureidopyrimidinone led to nanostructured hybrid silica, such as that depicted, as clearly shown by powder XRD studies. The nanostructuring was directly related to molecular recognition through hydrogen bonding. By combining FTIR, solution and solid-state NMR spectroscopic data, the transcription of the hydrogen-bonding networks from the precursor to the final product was clearly evidenced. © 2009, Wiley-VCH Verlag Berlin
  • No Thumbnail Available
    Item
    Silylated melamine and cyanuric acid as precursors for imprinted and hybrid silica materials with molecular recognition properties
    (Wiley-VCH Verlag Berlin, 2009-06-15) Arrachart, G; Carcel, C; Trens, P; Moreau, JJE; Man, MWC
    Two monotrialkoxysilylated compounds that consist of complementary fragments of melamine (M) and cyanuric acid (CA) have been synthesised. The molecular recognition properties of the M and CA fragments through complementary hydrogen bonds (DAD and ADA D = donor, A = acceptor) are the key factor used to direct the formation of hybrid silica materials by using a sol-gel process. These materials were synthesised following two methods: First, an organo-bridged silsesquioxane was obtained by the hydrolysis of the two complementary monotrialkoxysilylated melamine and cyanuric acid derivatives, with fluoride ions as a catalyst. The hydrogen-bonding interactions between the two organic fragments are responsible for the formation of the bridging unit. The transcription of the assembly into the hybrid material was characterised and evidenced by solid-state NMR (Si-29, C-13) and FTIR spectroscopic experiments. Second, the molecular recognition was exploited to synthesise all imprinted hybrid silica. This material was prepared by co-condensation of tetraethyl orthosilicate (TEOS) with the monosilylated cyanuric acid derivative (CA) templated by nonsilylated melamine. The melamine, template was completely removed by treating the solid material with hydrochloric acid. The reintroduction of the template was performed by treating the resulting material with all aqueous suspension Of melamine. These steps were monitored and analysed by several techniques, such as solid-state NMR (Si-29, C-13) and FTIR spectroscopic analysis and nitrogen adsorption-desorption isotherms. © 2009, Wiley-VCH Verlag Berlin